The limitation of the function of antitumour immune cells is a common hallmark of cancers that enables their survival. As such, the potential of immune checkpoint inhibition (ICI) acts as a paradigm shift in the treatment of a range of cancers but has not yet been fully capitalised. Combining minimally and non-invasive locoregional therapies offered by radiologists with ICI is now an active field of research with the aim of furthering therapeutic capabilities in medical oncology. In parallel to this impending advancement, the “imaging toolbox” available to radiologists is also growing, enabling more refined tumour characterisation as well as greater accuracy in evaluating responses to therapy. Options range from metabolite labelling to cellular localisation to immune checkpoint screening. It is foreseeable that these novel imaging techniques will be integrated into personalised treatment algorithms. This growth in the field must include updating the current standardised imaging criteria to ensure they are fit for purpose. Such criteria is crucial to both appropriately guide clinical decision-making regarding next steps of treatment, but also provide reliable prognosis. Quantitative approaches to these novel imaging techniques are also already being investigated to further optimise personalised therapeutic decision-making. The therapeutic potential of specific ICIs and locoregional therapies could be determined before administration thus limiting unnecessary side-effects whilst maintaining efficacy. Several radiological aspects of oncological care are advancing simultaneously. Therefore, it is essential that each development is assessed for clinical use and optimised to ensure the best treatment decisions are being offered to the patient. In this review, we discuss state of the art advances in novel functional imaging techniques in the field of immuno-oncology both pre-clinically and clinically. Cancer immunotherapy has been revolutionised through the introduction of immune checkpoint inhibitors (ICIs). By “reactivating” intratumoral antitumour T cells, there is potential for significant improvement in patient outcomes. Such outcomes can be further amplified by harnessing the potential for diagnostic and interventional radiology in the patient pathway. Diagnostic radiology has been integrated with immunotherapies for the purposes of diagnosis, screening and therapeutic response evaluation. The importance of accurate response assessment of imaging cannot be understated with scan interpretation holding a pivotal role in the decision-making process of a patient’s oncological treatment. Image interpretation can both prevent a patient being continued on a therapy course that has little benefit as well as effective therapies being stopped prematurely. This will become more vital in exploring interventional radiology as one of the next steps towards more personalised ICI therapy. These steps can be seen as the continued realisation of the synergistic relationship between immunology and radiology first recognised as early as 1974. The synergy between these interventions and ICI therapy promises improved patient outcomes in a variety of tumour types, following encouraging results reported in both animal models and preliminary clinical studies. The mechanisms underlying the complex interactions between these two modes of therapy have not been fully elucidated. However, one of the greatest theoretical advantages of combination ICI therapy is the enhancement of the innate immune system and consequent “abscopal effects.” In brief, treatment of a tumour at one site can lead to a reduction of systemic tumour burden. This is likely a result of activating antitumour specific cells via a variety of mechanisms and ICI may potentiate this systemic antitumour response. Considering the large number of permutations of interventional and ICI therapies, the optimal combination ICI therapies for specific patient and tumour characteristics have not yet been determined.Interventional radiology  offers a range of locoregional therapies (LRTs) ranging from stereotactic ablative radiotherapy, transarterial chemoembolisation (TACE), brachytherapy , thermal and cryoablation, irreversible electroporation and various therapeutic ultrasound bioeffects . Standardised imaging criteria have previously been developed prior to routine use of ICI therapies, however, further adaptations will likely be required for this new therapeutic avenue. Novel developments in diagnostic radiology will provide methods to establish the optimal LRT for specific conditions as well as implement more advanced standardised methods for evaluating response. Such information can then better guide subsequent clinical decision-making regarding the selection, scheduling, change or termination of combined therapy. Advances in radiological practice in this context are essential as the advent of liquid biopsy will inevitably lead to a greater volume of imaging to screen for cancer earlier and evaluate therapeutic response. This article first provides a background for a range of LRTs which is followed by a review of the new imaging modalities that could benefit the choice and therapeutic evaluation of combined locoregional intervention and ICI oncological therapy. Such technologies if implemented effectively have the potential to make significant progress in the advancement of personalised medicine . While ICI monotherapy can benefit patients through their ability to “remove the brakes” to facilitate the activation of antitumour-specific T cells, it is rarely curative for the majority of cancer types. Systemic monoimmunotherapy can provide objective response rates as high as 45% as for advanced melanoma and 40% for colorectal cancer but lower response rates are observed for lung cancer (26%), breast cancer (24%) and hepatocellular carcinoma (HCC) (17%). As such, the efficacy of using more than one immunotherapy has been assessed in more recent clinical trials. A combination of ICI therapies significantly improve median overall survival in cases of advanced melanoma (39.1 vs 18.5 months), HCC (18.7 vs 11.7 months) and lung cancer (17.1 vs 15.7 months) compared to monotherapy. However, such strategies while conferring greater therapeutic benefit, increase the toxicity and consequent risk of adverse events. Combining ICI with LRTs may limit side-effects while improving patient outcomes.The potential of ICIs was realised in 2010 when the first Phase III clinical trial of ipilimumab, a CTLA-4 inhibitor, was reported. Advanced melanoma patients treated with a combination of ipilimumab and the peptide vaccine, gp100, benefitted from an increase in median overall survival from 6.4 to 10.0 months, compared to those treated with gp100 alone. Y90 loaded on microspheres is delivered to a tumour via the feeding arteries. At this site, Y90 β radiation causes damage with limited injury to the surrounding normal parenchyma. Notably, Y90 therapy has demonstrated non-inferiority to other cancer treatments such as sorafenib, providing equal overall survival rates and decreased adverse events in locally advanced HCC.Brachytherapy is the delivery of internal  radiotherapy, often through use of wires, seeds or other implanted devices. Of note, more recent advances have led to the targeted delivery of radioactive particles via the blood supply to the tumour. This includes the use of Yttrium-90 (Y90) transarterial radioembolisation (TARE), typically used in the treatment of HCC. Thermal ablation can be delivered as radiofrequency ablation (RFA) or microwave ablation (MWA). The efficacy of RFA, measured by recurrence-free survival has been found to be comparable to surgical resection in the treatment of HCC patients with early stage disease. Interestingly, while cryoablation and RFA provide similar efficacy in local HCC progression, cryoablation may be less utilised in the future for liver ablations due to its association with increased risk for complications including “cryo-shock,” renal impairment and thrombocytopaenia. In contrast, cryoablation has an emerging role in renal cell carcinoma (RCC) having been found to be non-inferior to MWA for adverse effects and long-term outcomes.Percutaneous ablation involves the insertion of needle-like probes directly into the tumour to deliver high-energy heat  or cold (cryoablation) exposure, causing coagulative necrosis of the tumour.<3cm. Irreversible electroporation (IRE) is non-thermal ablative intervention that generates external electric fields to form hydrophilic pores in cell membranes without damaging surrounding vital structures such as the vasculature or ducts. IRE is now being explored clinically for treatment of tumours such as unresectable pancreatic cancer given minimal off-target effects and the benefit of sparing vital structures such as the coeliac trunk. While IRE alone has increased survival in unresectable pancreatic cancer from 6 to 14 months, combination with immunotherapy may further improve patients outcomes. Murine and human clinical studies evaluating IRE have indeed found increased intratumoral immune response as well as overall survival rates, particularly when combined with immunotherapy.Another recent study has demonstrated comparable overall survival and disease-free survival for percutaneous MWA and surgical resection of colorectal liver metastases for small resectable lesions  Clinical applications of focused ultrasound, including HIFU are being trialled with promising results with several clinical approvals already in place including ablation of symptomatic uterine fibroids. HIFU has been demonstrated to confer very high survival rates for the treatment of contained prostate cancer treament. HIFU has limited success for high risk prostate cancer patients and in low- to intermediate risk patients may confer improved urinary continence but greater treatment failure rate in comparison to laproscopic radical prostatectomy. Focused ultrasound’s versatility is highlighted by its ability to enhance drug delivery non-destructively. At lower powers, focused ultrasound can also induce localised, subablative intratumoral hyperthermia and this bioeffect has been under clinical investigation for drug delivery in liver tumours. Focused ultrasound mediated cavitation can drive higher concentrations of macromolecular drugs, including immunotherapies, into solid tumours.In contrast, focused ultrasound is a form of non-invasive targeted tumour therapy which can be used for a variety of bioeffects including high intensity focused ultrasound (HIFU), consequent with thermal ablation, subablative hyperthermia and cavitation. HIFU waves targeted to a specific location can cause tissue damage via two broad mechanisms: thermal and mechanical. Broadly speaking, thermal tissue damage shares a linear relationship to exposure time and an exponential relationship to temperature rise . Mechanical damage is exerted by a combination of radiation force and the formation of cavitation bubbles that can either undergo vigorous oscillations resulting in shockwaves forming upon implosion or rapid movements causing shear forces on the surrounding tissue. There are two types of TACE, conventional (cTACE) and the novel drug-eluting beads (DEB-TACE). In cTACE a cytotoxic drug, commonly doxorubicin, emulsified in a radio-opaque contrast agent called lipiodol, is delivered to the hepatic arterial system via an intra-arterial catheter injection near to the tumour site. This results in downstream ischaemic necrosis by both cytotoxicity and ischaemia by compromising the tumour vasculature. Multiple trials and reviews have found TACE can increase overall survival when compared to conservative management of pain and complications, for unresectable HCC culminating in its incorporation into clinical guidance. DEB-TACE in contrast involves the delivery of beads to the tumour that both embolise the microvasculature of the tumour and simultaneously release a cytotoxic drug at a sustained rate over an extended period of time. In theory, this approach provides increased tumour and decreased systemic concentrations of the cytotoxic drug, however, clinical results are conflicting and therapeutic benefit is likely dependent on tumour staging.TACE is currently considered the standard treatment for patients with intermediate stage HCC based on the Barcelona Clinic Liver Cancer scoring system (BCLC). This “abscopal” effect is a shared phenomenon of LRTs. LRTs broadly promote an inflammatory microenvironment, however, there is a disparity in the immunogenicity of each ablative technique. This difference may partially account for the varying responses observed in patients treated with the same technique. It has been suggested that RFA can have pro-oncogenic effects such as greater IL-10 and TGF-b response post-treatment, but the exact mechanisms are unclear. Upon comparison non-ablative interventions such as HIFU, IRE, MWA and cryoablation more reliably generate a proinflammatory response which results in antitumour immunity. Post-Y90 therapy, increases in proinflammatory markers such as IL-1 and oxidative markers such as malondialdehyde have been observed. Similarly, cryoablation likely generates a greater inflammatory response than RFA as evidenced through greater IL-1b, IL-6 and TNF-a responses in rat models. Clinically, MWA and cryoablation have recently been found to be at least as efficacious if not superior to RFA in the treatment of HCC and liver metastases. Tumour-specific T cell responses have been observed in patients treated with MWA, which are associated with longer progression-free survival and remission. It has been postulated that these interventions generate an in situ tumour vaccine by creating a pool of tumour-associated antigens. Furthermore, non-ablative techniques have a higher likelihood of preserving tissue structure and neoantigens for immune cells to infiltrate and target whilst causing sufficient damage to the tumour. In keeping with this theory, T cells from patients treated with cryoablation exhibited a polyclonal shift indicating a greater variety of antigens are being recognised, likely due to the exposure of multiple tumour antigens following ablation. Correspondingly, a clinical HIFU study in breast cancer found that ablation of breast lesions lead to increases in both total immune cell populations as well as activated cytotoxic T cells in the axillary lymph nodes. However, it remains that the heterogeneous nature of the application of each LRT and cancer type complicates the decision as to which therapy is best for each patient.In 1953, it was observed that targeted external radiotherapy of one tumour area appeared to result in an antitumour response in distant areas due to stimulatory effects on the immune system. This extends to other tumour types as increases in the peripheral blood CD8:Treg ratio are observed post thermal ablation of lung, leiomyosarcoma, desmoid, liver and bone tumours. Similarly, myeloid-derived suppressor cells (MDSCs) which are associated with worse prognosis in HCC are decreased post-RFA. However, the ability to generate a proinflammatory TME and change the immune system landscape is inconsistent. Contrasting studies have found TACE to not significantly increase TAA-specific CD8 T cell populations. In addition, a recovery of anti-inflammatory cells and loss antitumour functions in the long-term post-treatment have been observed. Conversely, pro-tumourigenic effects have also been observed with use of some LRTs. Pro-oncogenic factors such as hypoxia inducible factor 1 a and vascular endothelial growth factor (VEGF) are increased post-RFA and TARE. Nevertheless, it is likely that LRTs that promote antitumour immunity would benefit from augmentation by ICI therapy and these responses are tumour-specific.These effects culminate in the conversion of the tumour microenvironment (TME) to become proinflammatory and facilitate immune cell infiltration. T regulatory cells (Tregs) are typically raised in HCC patients compared to healthy individuals, however, this is significantly reduced post-TACE. In one study combining TACE with tremelimumab, authors identified an increase in the accumulation of intratumoural CD8+ T cells in all patients. However, it is not possible to determine the contribution of TACE in this context as previous trials with tremelimumab have been performed in these patients with a better baseline and prognosis. In contrast, one study did not find any increase in lymphocytic tumour infiltration using combination ICI and Y90 radioembolisation therapy. Interestingly, ablation post anti-PD-1 therapy in patients with stable disease or atypical responses, led to improved objective response rates and median survival. As these trials are limited in number and sample size, current and further larger randomised trials comparing ICI with and without LRT will help establish optimal therapies.Multiple case reports and a handful of trials of combination ICI and LRT therapy have been already performed Supplementary Material 1.Click here for additional data file.While outcomes from these trials can be simplified to patient survival metrics it is crucial to recognise the patterns of response to therapy, most often facilitated through imaging, as ultimately this will inform clinicians if therapies are efficacious or futile for a particular patient. To effectively evaluate imaging across trials and practice, standardised criteria have been developed and modified over the last 50 years. Standardised criteria may need to be further tailored for this new therapeutic avenue to not only compare outcomes between trials but also guide clinical decision-making regarding continuation, switching or cessation of therapies. This criteria provided a standardised and quantifiable method to evaluate the response of a solid tumour to therapy using imaging based on the longest measurable dimension of tumours. In modern clinical practice, CT is preferred imaging modality for RECIST and provides the workhorse, although MRI, PET and plain film are also applicable. . Responses are categorised as complete response (CR), partial response (PR), no change (NC) or progressive disease (PD). Several iterations of RECIST have since been developed with arguably the most important change being immune-related response criteria (irRC). RECIST 1.1 introduced a new method to determine if lymph nodes were pathological as well as providing new methods to measure disease progression. However, the concept of maximum tumour diameter integral to RECIST was not developed with immunotherapies in mind. This becomes most evident with the “pseudoprogression” phenomenon which is the apparent increase in tumour burden  soon after immunotherapy delivery. This is in fact not due to metastatic growth or progression but rather T cell intratumoral infiltration after the ICI removes the “brakes” of the immune checkpoint. This beneficial response would otherwise be incorrectly regarded as PD according to RECIST 1.1. The irRC accounted for this through the requirement of two consecutive studies exhibiting progression for true PD to be defined. The development of RECIST is summarised in Imaging has been used extensively to assess response to cancer therapy. The most commonly used criteria is the “Response Evaluation Criteria in Solid Tumours” (RECIST) first published by the World Health Organisation (WHO) in their 1979 WHO handbook and in 1981 by Miller et al and at the turn of the century, formalised by the RECIST Working Group. Whilst phenomena such as pseudoprogression are not common, with rates ranging from 1.49 to 11.11%, it may become more prevalent with the uptake of combination ICI therapies. LRT may initially shrink the tumour lesion but then be more readily followed by significant lymphocytic infiltration upon ICI. This will undoubtedly be influenced by the scheduling of checkpoint inhibition and specific combinations used. RECIST must be adapted to cater for this and other eventualities to ensure unnecessary termination of therapy is avoided while not risking poor detection of true PD.Further adaptations to existing commonly used response metrics including RECIST, PERCIST and CHOI, may be needed for assessing combined locoregional and ICI therapy. Similar modifications will likely be required across multiple tumour types to correctly evaluate the potential of locoregional and combined therapies in trials. Target lesions suitable for LRT may require development of new evaluation criteria to monitor response accurately. This includes the iRECIST guidelines that require a size threshold  which may not be met for locoregional targets.In the context of LRT response, further limitations must also be addressed. Incorporation of viable tumour measurements such as through arterial enhancement in the modified RECIST (mRECIST) for HCC, have shown superiority to older criteria that do not consider this parameter in predicting overall survival of HCC patients treated with LRTs.Repeat LRT is performed and might be shown in future trials to synergistically act with ICIs to create a sustained immunological pressure to breakthrough immunoinhibitory pathways. This could be most noticeable in the setting of non-thermal ablative techniques whereby tissue architecture is preserved. However, using these metrics to evaluate therapeutic response can be complicated by previous LRT to the same tumour lesion. Furthermore, a patient who experiences significant reduction of a lesion targeted by LRT may only be classed with SD if small lesions not suitable for LRT intervention or are not treated as effectively are still included in the evaluation. These challenges are compounded by the lack of information regarding optimal timing of imaging follow up for combined therapy which may lead to inaccurate assessment of responses. Whilst observations of abscopal effects from LRTs in isolation are rare, the potential remains to misclass these phenomena as new lesions and as a result disease progression.The immune-oncology field would benefit from the widespread implementation and standardisation of emerging novel diagnostic imaging techniques. A combination of both anatomical imaging, specific to the tumour and functional imaging specific to the immune system, would enable better differentiation between pseudoprogression and PD and guide clinical decisions regarding the patients’ treatment. The power of such information also enables researchers to identify shared characteristics between and within experimental arms in trials demonstrating benefit from specific therapies, which may be tailored to specific tumour biomarkers. Such results could be used to design more “focused” trials and take a step towards personalised therapies with new criteria for patient stratification. In addition, patient-specific combined imaging may also provide insight into the complex interactions between LRTs and ICI at a more functional level.Few clinical trials of combined, locoregional and ICI therapy have been completed, however, there are many currently taking place 18F-FDG) used with positron emission tomography (PET) is a now widely adopted functional imaging radiotracer used in oncology. As a labelled glucose analogue, this imaging method capitalises on a tumour’s inherent higher metabolic state resulting in greater uptake at the tumour site and thus stronger emitted signal intensity. While typically used for detection of pathologies including cancer and infective foci, 18F-FDG PET-CT has also been investigated for predicting prognosis. For example, 18F-FDG PET-CT measurements in NSCLC have been found to be reliable predictors of efficacy and patient survival at 2 weeks and 1 month post-nivolumab initiation. There is evidence to suggest that tumour and immune cells compete for glucose in the microenvironment. As such, the heightened tumour metabolism depletes this resource for tumour infiltrating T cells, resulting in dampened effector function. Furthermore, this is possibly linked to other tumour suppression pathways as expression of programmed death ligand-1 (PD-L1) has been shown to promote cellular pathways that drive tumour glycolysis. Positive correlations between 18F-FDG and PD-1/L1 expression in lung cancer and CD8 T cell infiltration have also been demonstrated. However, 18F-FDG cannot be considered as a clinically reliable surrogate for either as correlations were too weak for statistical significance. Furthermore, the relationship between 18F-FDG PET-CT and PD-1/PD-L1 expression is either tumour-specific or inconsistent, with direct proportionality demonstrated in bladder cancer but inverse proportionality in oral squamous carcinoma.Radiolabelled fludeoxyglucose  due to the possibility of misinterpreting unrelated synchronous events that exhibit increased glucose metabolism. To illustrate, a NSCLC study found 21% of patients treated with pembrolizumab or nivolumab who were classified as PD by 18F-FDG PET-CT, were in fact pseudoprogression and another 17% had dissociated responses. Moreover, all these patients experienced clinical benefit from continued ICI. The “PET Response Criteria in Solid Tumours” (PERCIST) was the original standardised criteria for evaluating 18F-FDG PET-CT. In a modification that mirrored the evolution of RECIST to irRC, “immune PERCIST” (iPERCIST) was developed which accounted for pseudoprogression by requiring confirmation of progressive metabolic disease at a second PET scan 4–8 weeks later.A significant limitation of 89Zr-Nivolumab, was carried out in 13 advanced NSCLC patients prior to nivolumab therapy. PET uptake of 89Zr-nivolumab correlated with histologically confirmed PD-1 positive tumour infiltrating immune cells (p = 0.03) and higher peak signals were observed in therapy-responsive lesions >20 mm (p = 0.019), likely limited by the partial volume effect. Tumour lesion uptake was also shown to be heterogeneous between and within patients and was a stronger predictor for progression-free and overall survival compared to lab-based predictive biomarkers  may limit their penetration and uptake by tumours in comparison to the radiolabeled glucose tracer 18F-FDG (~180 Da), three orders of magnitude smaller.“Checkpoint labelling” is the direct radiological labelling of markers targeted in checkpoint inhibition through antibodies or related smaller molecules. The first in-human study for omarkers .121 Wh18F-BMS-986192 (labelled anti- PD-L1 adnectin) systemically which specifically bound to PD-L1 +ve regions. Another anti- PD-L1 adnectin radiotracer also proved to correlate clinically with PD-L1 tumour expression and tumour lesion response to therapy. While statistically significant correlation for overall patient response to therapy as a whole was not demonstrated, the small sample size (n = 13) rather than poor radiotracer capability could account for this shortcoming. PD-L1-specific affibodies  have also been designed and tested in vivo in mice and rhesus monkeys and confirmed specific tracer uptake in PD-L1 positive tumours on the same day as tracer administration. This feature possibly overcomes practical limitations of whole antibody approaches which can take 5–7 days for sufficient blood clearance post-PET tracer administration. This technique conceivably further opens the avenue to precision medicine; i.e. functional imaging driving towards bespoke treatment plans based on ICI screening and monitoring.Smaller protein structures such as adnectins (~40 kDa) have been designed as radiotracers to bind to specific checkpoint inhibitors. In a proof of concept study, mice bearing PD-L1 -ve and +ve xenograft tumours were administered in vivo mouse study demonstrated successful use of a 89Zr-CD8 minibody (antibody binding region fragment) for labelling T cells, generating a heatmap of PET signal within the tumour for T cell density  has been shown to be safe for human use and has increased uptake in bone marrow and lymphoid organs. When 18F-CFA PET was used in three glioblastoma patients being treated with immunotherapy, one patient’s intratumoral signal was elevated three-fold 3 weeks post-treatment. This corresponded with MRI confirmed immune infiltration and is a suggestive of therapeutic response. However, a decrease in signal was observed in another patient who received bevacizumab (anti-VEGF). This is possibly accounted for by the decreased perfusion, determined by advanced MRI, as a result of this therapy. It is unclear whether labelling salvage pathway metabolites will enable differentiation between pseudoprogression and true progression. Contrasting studies have identified 18F-CFA PET as a potential marker for HCC imaging of cancer cells due to their higher proliferation rate and similar reliance on the salvage pathway. It is possible this is dependent on the tumour type, therefore, further studies are required to determine the utility of these radiotracers in combined therapy for different tumour subtypes. Other studies have begun investigating the use of cytokine labelling as prognostic factor pre- and post-ICI but these are early in development with limited success to date and similarly to other types of tracers, is likely to be cancer specific.While the presence of intratumoral T cells may indicate therapeutic response, T cell antitumour function can be limited due to the immunosuppressive mechanisms and T cell exhaustion. To determine if LRTs and ICIs are able to “reactivate” T cells, markers of T cell activity can be evaluated. PET radiotracers of the salvage pathway of DNA synthesis have been developed, as immune cells are predisposed to use these metabolites to facilitate their heightened proliferation rate. In a mouse model, the PET imaging agent GZB was tested for quantifying granzyme B release at CT26 and MC38 tumour sites before and after anti-PD-1 and anti-CTLA-4 therapy. GZB PET signal positively correlated with CD8 T cell subpopulations and Th1 inflammatory cytokines and negatively correlated with immunosuppressive cell types at the tumour site and anti-inflammatory cytokines at draining lymph nodes for MC38. A different approach to granzyme B imaging has also been developed where a small peptide “nanoreporter” is conjugated onto the ICI and is cleaved by granzyme B to activate a fluorescent signal which is detected non-invasively. Higher signal levels were observed in therapy-responsive tumours of treated mice compared to those with therapy-resistant tumours or not treated. Intriguingly, this signal was detected before tumour shrinkage was observed with other imaging modalities and was reported to correspond with survival rates. Other mouse model studies have also found a strong predictive ability of granzyme labelling to distinguish between responders and non-responders to ICI. Despite not yet being investigated in human trials, granzyme B appears to be a promising target for characterising the TME to assess therapeutic response.A T cell specific alternative is “enzyme labelling,” including granzyme B which is expressed by activated CD8 T cells and is involved in immune mediated tumour cell killing. Non-cellular aspects of the inhibitory TME such as hypoxia should also be considered and novel BOLD MRI techniques may also have a supportive diagnostic role here. Carbonic anhydrase (CA) contributes to the acidification of the TME under hypoxic conditions and is strongly expressed by some tumours. CA expression was also found to correlate with intratumoral Foxp3+ T cell density and poorer survival in NSCLC patients. Labelling of CA has already been demonstrated in renal cell cancer patients for lesion detection and as a marker for poor prognosis. However, there is no evidence to suggest whether CA is prognostic for therapeutic response to locoregional intervention or ICI. By contrast, imaging of normalising extracellular pH post-LRT has been identified as a positive prognostic factor for therapeutic response in animal models and may have a role in clinical assessments with further validation. CEST MRI may have a supporting diagnostic role in this regard.For screening and prognostic purposes, it may be useful to characterise the inhibitory aspects of the TME as well. Anti-CD11b radiotracers have been developed to image “myeloid derived suppressor cells,” which are known to be an important negative prognostic marker for response to ICI, and have accurately characterised the TME in mouse models. Furthermore, the immunoinhibitory limitations posed by a hypoxic environment may not be present in well-vascularised tumours. These lesions might be easier targets for combined locoregional interventions and immunotherapy as found in the use of antiangiogenic therapies. It has also been proposed that MRI perfusion studies may enable clinicians to differentiate between tumour recurrence and necrosis. If validated, incorporating this modality post-LRT in follow-up will ensure greater accuracy of response evaluations.Evaluating the tumour vasculature has enabled clinicians to not only determine the tumour’s ability for local invasion and metastasis but also predict response to different therapies. Greater tumour perfusion may allow for superior drug delivery and immune infiltration. In separate studies, greater blood flow on CT perfusion studies for rectal carcinoma and head and neck cancers were associated with better chemotherapy and radiotherapy responses. The algorithm was trained by combining the contrast-enhanced CT scans of 135 patients with advanced solid tumours from the MOSCATO trial, with respective RNA-sequencing data of the CD8B gene. From 84 input variables, 8 variables were retained during the training step to generate the radiomic signature which included a combination of location, density of the peritumoral peripheral ring, kilovoltage peak and grey-level emphasis. The radiomic score indicated whether there was high or low abundance of CD8 infiltrate on analysis of a CT scan. The algorithm was validated with additional data sets of known CD8 T cell infiltration density. Furthermore, a higher radiomics score, indicating an inflamed tumour, was associated with objective response at 3 and 6 months post-anti-PD-1/PD-L1 therapy as well as overall survival.Radiomics is a field that involves using algorithms to automatically extract and quantify features from an image. This approach has been employed to characterise tumours as inflamed or non-inflamed using the CD8 cell signature. Multiple models have also been developed to predict prognosis of HCC patients post TACE therapy. It has generally been found that models which incorporate both radiomics and clinical features such as α-fetoprotein and Child-Pugh score (score of severity of long-term liver disease) perform best in predicting survival.As with cellular labelling, this characterisation has implications for LRT in assessing whether lesions would benefit from direct intervention to switch a tumour from non-inflamed to inflamed even before using ICI for a specific patient. Pathological studies have shown superiority of selective internal radiation (SIRT) over TACE for intratumoral effector T cell recruitment in HCC. The ability to verify T cell infiltration intra- or post-operatively and by tumour region, without need for an invasive biopsy, will lead to more informed decision-making regarding additional interventions or ICI use. It is inevitable that future directions will see increasing application of radiomics to such novel imaging techniques for the purposes of advancing diagnostic and prognostication in oncology and guiding optimal immunotherapy treatments. In-depth characterisation of the whole TME by imaging can be achieved unlike biopsies which can only sample a small fraction of the heterogeneous TME. Screening patients could be performed to ensure specific therapies are only considered for those with predicted therapeutic benefit. Stratification in this manner will likely improve patients’ outcomes and limit futile treatments, avoiding delays in appropriate treatment and eliminate unnecessary adverse effects. In addition, it may lead to greater personalisation of combined locoregional and ICI therapy. Prognostic characteristics within patient treatment groups may also be identified with more imaging modalities available. This will likely include integration of liquid biopsy data which through analysis of hypermutated ctDNA and microsatellite instability could predict which patients would best respond to ICI therapy. Such findings can then be used to guide future trials and clinical practice , intravoxel incoherent motion DWI (IVIM-DWI), functional MRI, BOLD MRI and perfusion studies.practice . In parallel, the use of case series would provide a foundation for future larger scale trials.The therapeutic potential of combined locoregional and immunotherapy may be game changing in the development of more successful oncological treatments in the era of personalised medicine. However, we remain early in this journey and there are several broad and specific challenges. The realisation of this therapeutic pathway will rely on the success of several carefully designed pivotal clinical trials, as there are many combinations of LRTs, immunotherapies and imaging modalities. Furthermore, the relative timing of the therapies and imaging as well as the criteria to be adopted is not consistent. The heterogeneous nature of these trials across a wide range of tumour subtypes may complicate comparisons and weaken conclusions to be made for future evidence-based practice. The expense of such combination device and drug trials can be prohibitive, both in terms of setup costs of earlier phase trials to demonstrate safety and in later phase trials where large numbers of patients are likely to be required to demonstrate efficacy. A plausible solution may include the use of a modified basket or umbrella trial whereby patients are first screened by biotracers discussed in our review and then allocated to specific trial arms. Combination ICI therapy and LRT may go some way to addressing this, but this comes at the cost of increasing toxicity and consequent adverse effects. Further, the response evaluation of LRTs may be more challenging due to previous interventions including radiotherapy and ablation.As with all cancer treatments, there is likely a biological limitation in some patients through the inevitable selection process of resistant cancer cells and immunologically “cold” tumours.Overall, there are multiple imaging techniques and modalities, including functional imaging, that diagnostic radiology can offer to support the field of immunotherapy. Specifically, this may be in terms of diagnosis, directing therapy and following treatment response, but furthermore in tailoring the most appropriate immunotherapy treatments and LRTs. Stepwise advances towards more and more personalised oncological treatment pathways are continuously being made. Both non-invasive and minimally invasive forms of diagnosis and treatment are being developed and implemented. The widespread adoption of liquid biopsy is approaching for screening, diagnosis and prognostication, which in combination with the novel imaging techniques discussed, will provide even more information to enable multidisciplinary teams to effectively generate patient-specific algorithms for treatment and surveillance. Different LRTs have theoretical benefits to being used in combination with ICIs thus, many trials are now taking place. Diagnostic radiology has become pivotal in the field of immunotherapy and its utility will only increase with combined ICI and interventional radiological therapies now being actively pursued. The synergy between LRTs and ICI is only now beginning to be assessed clinically and is in no way optimised. To ensure all relevant information can be extracted from these trials, existing radiological response metrics may need to be adapted and implemented. Incorporation of new imaging technologies into patient screening and therapeutic response evaluation will facilitate progress. This will enable relevant comparisons within and between trials to be made as well as provide more information for clinical decision-making regarding treatment. The future of medical oncology is pivotal on the integration of these new technologies, treatments, and expertise of the multidisciplinary team including close collaboration between oncologists and radiologists.


Visual outcomes after primary tumour treatment of uveal melanoma (UM) have been investigated repeatedly. This study evaluates the correlation between best-corrected visual acuity (BCVA) before treatment with clinicopathological factors and patient survival.Pre-treatment BCVA was examined in relation to tumour dimensions and location, and survival in a retrospective cohort of 1809 patients who underwent plaque brachytherapy. BCVA was also correlated to tumour histological factors in a second cohort of 137 enucleated eyes.p = 0.19) and had similar frequency of ciliary body involvement (p = 0.99) but had tumours with greater apical thickness (p < 0.0001), greater diameter (p < 0.0001) and shorter distance to the optic disc and fovea (p < 0.0001). There were no significant relations between low BCVA and any of 13 examined tumour histological factors at a Bonferroni-corrected significance level (p > 0.004). Patients with low BCVA had greater incidence of UM-related mortality in competing risk analysis (p = 0.0019) and shorter overall survival (p < 0.0001). Low BCVA was also associated with increased hazard ratio (HR) for UM-related mortality in univariate analysis , but not in multivariate analysis with tumour size and location as covariates.The mean BCVA of the tumour eye prior to plaque brachytherapy was LogMAR 0.42 (SD 0.46). Patients with low BCVA (LogMAR ≥ 1.00) did not differ in age (UM patients with low BCVA before primary tumour treatment have a worse prognosis, likely related to increased tumour dimensions. Future studies should examine the prognostic significance of BCVA in relation to macula-involving retinal detachment and genetic factors. Uveal melanoma (UM) is the most common primary intraocular malignancy, affecting more than 7000 individuals each year worldwide . UMs mosMany studies have reported short and long-term visual outcomes after plaque brachytherapy and other eye-preserving treatment modalities –16. ThesHistologically, UMs are identified as dome-shaped, mushroom-shaped or lobulated masses of atypical melanocytes with varying degrees of pigmentation and vascularity –24. TypiOne could perhaps assume that a correlation between low VA and large tumour size, and thereby poor prognosis, is self-evident and that such a basic correlation as the prognostic importance of visual acuity in the tumour eye would have been examined repeatedly. A reduced VA in UM could however be caused by several factors not related to tumour size or location, including but not limited to retinal detachment, tumour infiltration of the retina, bleeding, necrosis, inflammation, and cataract from direct contact between tumour and lens. And quite surprisingly, we are only aware of one previous study that has examined the implication of VA before treatment for patient survival, and none that has included histological characteristics. In a cohort of UM patients treated with plaque brachytherapy published in 2018, Snellen visual acuity ≤ 20/200 (LogMar ≥ 1.00) was associated with increased hazard ratio (HR) for metastasis in univariate Cox regression . VA was The first cohort consisted of clinical data from consecutive patients with UM treated with plaque brachytherapy between the years 1980 and 2017 at St. Erik Eye Hospital, Stockholm, Sweden. Pre-established inclusion criteria were: Availability of all the clinical data parameters detailed below. Exclusion criterium was: Less than three years of follow-up. The apical thickness of all tumours had been measured with A and B-scan ultrasonography at diagnosis. Tumour diameters and distances to the optic disc and fovea had been measured upon examination with slit-lamp biomicroscopy and wide-field fundus photographs at the same occasion. Plaque brachytherapy was typically initiated one to three weeks later.The second cohort consisted of paraffin-embedded and formalin-fixed eyes that underwent primary enucleation for UM between the years 1985 and 2010. For diagnostic purposes, these had previously been stained with haematoxylin and eosin, as well as periodic acid-Schiff (PAS) without haematoxylin counterstain. Inclusion criteria were: Histologically proven melanoma originating from the choroid or ciliary body, and availability of all the clinical data parameters detailed below. Exclusion criteria were: No or too little tumour tissue represented in section, extensive tumour necrosis, haemorrhage or inflammation, heavily pigmented tumour affecting visual examination and suboptimal staining results, determined by positive and negative internal and external controls, and patient still alive . One representative section from each eye was digitally scanned at × 400 using Nano Zoomer 2.0 HT scanner  as described previously –44. The For both cohorts, clinical data on patient sex, age at diagnosis, best corrected visual acuity (BCVA), tumour thickness, tumour diameter, tumour distance to the optic disc and fovea, presence of retinal detachment , other ocular diseases , AJCC T category, date of diagnosis and vital status at last follow-up  were obtained from our treatment registry . The regThe study follows the tenets of the Declaration of Helsinki and the research group’s internal data security policy for sensitive data. Ethical permission was obtained from the Regional Ethics Review Board in Stockholm (reference 2019–03485) and from the Swedish Ethical Review Authority (record number 2020-02835). According to the approved ethics application, the requirement for written informed consent was waived for the first cohort because this was a retrospective study that did not require collection of identifiable health information including patient names, personal identifiers, addresses, other contact details or photographs, and did not affect treatment or follow-up of the patients. Similarly, the requirement for written informed consent was waived for the second cohort as only deceased patients were included.Best corrected visual acuity (BCVA): Each patient’s VA had been measured according to a standardized methodology one to three weeks prior to treatment by an optometrist or ophthalmic nurse at the Ocular Oncology Service, St. Erik Eye Hospital. A KM-chart in an illuminated light box was used and patients tested at a distance of 3 m . The BCVLow and high BCVA: The measured BCVAs were dichotomized so that high BCVA was defined as LogMAR <1.00 ; and low BCVA as LogMAR ≥ 1.00 , following a previously used classification , 49. In In the second cohort, patterns of microvascular loops and networks were assessed in a light microscope through a green narrow band pass filter according to the method described by Folberg et al. . For stap < 0.05 were considered significant, all p-values being two-sided. Shapiro-Wilk tests were used to evaluate the deviation of continuous variables from normal distribution. If the test was significant (p < 0.05), the Mann Whitney U tests were used, otherwise Student’s t-test were used. Violin plots and linear regression were used to evaluate tumour thickness, diameter and distance to the optic disc and fovea in relation to BCVA. Uni- and multivariate Cox regression HRs for UM-related mortality in relation to BCVA, tumour dimensions and distance to the optic disc and fovea were calculated. Cumulative incidence function estimates from competing risks data were plotted with the cmprsk package for R, and the equality of survival distributions was tested with Gray’s test for equality [2) tests  or Fisher’s exact tests (if any field had a sample of <5). As this involved a large number of tests without preplanned hypotheses which would have increase the risk for type I error, Bonferroni correction was applied and the significance level was reduced to 0.004 (0.05 divided by 13) [Differences with a equality . Overalld by 13) . BCVA leOne thousand eight hundred and seventy patients met the inclusion criteria, of which 61 were excluded for lack of follow-up data. One thousand eight hundred and nine patients remained in the study. Of the 1809 patients, 896 (50%) were men and 913 (50%) were women. The mean age at diagnosis was 63 years (SD 14). The mean tumour thickness was 5.7 mm (SD 2.9) and the mean diameter 10.9 mm (SD 3.9 mm). The mean BCVA of the tumour eye prior to treatment was 0.42 (SD 0.46). One thousand five hundred and eight patients (83%) had high BCVA (LogMAR < 1.00) whereas 301 patients (17%) had low BCVA (LogMAR ≥ 1.00).Eight hundred and forty-five patients (47%) had deceased before the end of follow-up. Median follow-up for the 964 survivors was 10.1 years  and ciliary body involvement observable in slit-lamp biomicroscopy and/or ultrasonography. All other clinical factors  differed significantly. In linear regression, decreasing BCVA also correlated with older patient age Fig. .Fig. 1CoIn univariate Cox regression, lower BCVA, and greater tumour apical thickness, tumour diameter and tumour distance to the optic disc were associated with increased HRs for UM-related mortality. In multivariate regression, only tumour thickness and diameter retained their significance Table .Table 2Cp = 0.0019, Fig. p = 0.00052, Fig. In cumulative incidence function estimates of UM-related mortality from competing risks data, patients with low BCVA had significantly greater incidence of UM-related mortality than patients with high BCVA  n = 7 patient still alive, n = 6 no or too little tumour tissue represented in section, and n = 1 the represented tumour was completely necrotic). One hundred and thirty-seven eyes remained in the study. Of these 137 patients, 77 (56%) were men and 60 (44%) were women. The mean age at diagnosis was 65 years (SD 13). The mean tumour thickness was 8.0 mm (SD 3.3) and the mean diameter 14.0 mm (SD 4.6 mm). The mean BCVA of the tumour eye prior to enucleation was 0.75 (SD 0.68). Eighty-four patients (61%) had high BCVA (LogMAR < 1.00) whereas 53 patients (39%) had low BCVA (LogMAR ≥ 1.00).One hundred and fifty-one eyes met the inclusion criteria, of which fourteen were excluded  had other ocular diseases that may have contributed to a decreased BCVA. Of these, six (4%) had cataract, five (3%) had glaucoma, one (1%) had retinal scarring from a tuberculosis infection in childhood and two (1%) had mild diabetic retinopathy . An addi2 or Fisher’s exact p > 0.004, Upon histological examination, 39 tumours (28%) were composed of >90% epithelioid cells, 71 (52%) of mixed cell types and 27 (20%) of >90% spindle cells. Fourteen tumours (10%) had necrotic areas. Vasculogenic mimicry was identified in 48 tumours (35%). In contingency tables, there were no statistically significant relationships between low BCVA and any one of the examined tumour histological factors at the Bonferroni-corrected significance level (χBAP1 mutations, which are dependent of monosomy 3 etc.In this paper, we have examined correlations between pre-treatment visual acuity, clinical characteristics, patient survival and histopathological findings in eyes with UM. Patients with low BCVA had tumours with significantly greater apical thickness, diameter and significantly shorter distance to the optic disc and fovea. Patients with low BCVA also had significantly greater incidence of UM-related mortality, shorter overall survival, and increased HR for UM-related mortality. However, the association was not retained in multivariate analysis, and the likely explanation for the link between BCVA and patient prognosis is that patients with poor vision have larger tumours. One could perhaps ask if a risk factor that does not retain its significance in multivariate analysis is truly a risk factor at all. We would argue that low BCVA can potentially be caused by several factors not directly related to tumour size and location, as mentioned in the introduction. Further, even if two risk factors correlate strongly, they might me suitable for use in different situations: E.g., if a patient presents with an intraocular tumour and low BCVA, attending optometrists and ophthalmologists can be alerted to a potentially large tumour and poor prognosis well before an ultrasonography has been performed. Lastly, independence of relevant covariates is not a requirement for risk factors in UM and other tumours, or else we would have to abandon tumour thickness as a prognostic factor, which in many cohorts is dependent of tumour diameter; and BAP-1 immunoreactivity and Nevertheless, the correlation between low BCVA and larger tumours observed here is neither unexpected nor unprecedented . The disWe found no association between retinal detachment and poor BCVA. This highlights a limitation of this study: The data specified if detachment of any part of the retina could be observed by slit lamp biomicroscopy, but not if a retinal detachment involved the macula. Naturally, such involvement is strongly correlated with BCVA . One reaBAP1 mutations, BAP-1 expression or gene expression signatures, which are among the strongest prognostic factors in UM [Other limitations to this study include the limited sample used for histological correlations. It is possible that some of the correlations identified as non-significant, e.g., visual acuity and histological factors, would have been significant in a larger cohort. Not least postlaminar optic nerve invasion has previously been shown to correlate with decreased BCVA and poor survival in a larger study by Lindegaard et al. . Thirdlyrs in UM , 61. FifUM patients with low BCVA before primary tumour treatment have significantly worse survival, likely related to increased tumour dimensions. No significant correlations between BCVA and tumour histology including tumour cell type, degree of pigmentation, presence of necrosis, presence of subretinal fluid, extraocular growth, penetration of Bruch’s membrane, tumour infiltration of the optic nerve head or ciliary body and anterior segment involvement could be identified. Future studies should examine the prognostic significance of BCVA in relation to macula-involving retinal detachment, cytogenetic and gene expression factors.Visual outcomes after treatment of uveal melanoma have been investigated repeatedly. Surprisingly few studies have examined the correlation between visual acuity before primary tumour treatment with long-term patient outcomes.In a cohort of 1809 patients, we find that uveal melanoma patients with low visual acuity before treatment have greater incidence of uveal-melanoma-related mortality in competing risk analysis, and that they have shorter overall survival. This is likely related to the fact that patients with low visual acuity had significantly larger tumours. In the second cohort with 137 enucleated eyes, however, there were no significant relations between low visual acuity and any one of 13 examined tumour histological factors at a Bonferroni-corrected significance level.Supplementary TableSupplementary Figure


BackgroundAnimal models of distributive hypotension and resuscitation allow the assessment of hemodynamic monitoring modalities and resuscitation strategies. The fluid-first paradigm for resuscitation is currently being challenged with clinical trials. In this investigation, venous return and perfusion are assessed, and full hemodynamics are characterized, in a porcine model of endotoxemic hypotension with and without fluid pre-loading.MethodsTwo groups of six pigs had the induction of standardized endotoxemic hypotension . Group 1 underwent four 10 cc/kg crystalloid boluses, and Group 2 was not fluid pre-resuscitated. Both groups underwent progressive norepinephrine (NE) up-titration to 0.25 mcg/kg/minute over 30 minutes. Vital signs, central parameters, and laboratory values were obtained at baseline, “critical hypotension,” after each bolus and during NE administration.Results-5 versus 738±258 dyn/s/cm-5; P=0.03) and Group 2 . In Group 1, the four fluid boluses decreased heart rate (HR), pulmonary capillary wedge pressure (PCWP), and central venous pressure (CVP) (P<0.05). No changes were observed in blood pressure, cardiac output (CO), or lactate. NE up-titration increased HR in Group 1 and decreased CVP in both groups. Higher final CVP  and PCWP  values were observed in Group 1 relative to Group 2, reflecting increased venous return.Endotoxemia decreased the systemic vascular resistance (SVR) in Group 1  was preserved by increased NE-induced chronotropy. Distributive shock is characterized by low systemic vascular resistance (SVR), with associated hypotension and malperfusion. To attempt to augment perfusion, this form of shock is considered hyperdynamic, as the heart is forced to increase its inotropic and chronotropic activities. Sepsis and septic shock due to bacterial infection are the most frequently encountered forms of distributive shock and the most common cause of mortality in the intensive care unit (ICU). Management principles have been driven by the Surviving Sepsis Guidelines, recently updated in 2021, in which treatment is tailored to the normalization of mean arterial pressure (MAP) >65 mmHg) and the reduction of serum lactic acid levels . Insuffi mmHg andWhile distinct from bacterial sepsis, endotoxemia due to bloodstream seeding with lipopolysaccharides (LPS) similarly produces low-SVR hypotension ,7. ModelLarge animal models of endotoxemia are highly useful to clinicians and scientists alike, as they can be used to assess resuscitation strategies, test novel hemodynamic monitoring modalities, and characterize perturbations seen in distributive hypotension and shock ,11. The To induce low-SVR hypotension, a previously reported porcine model of intravenous (IV) LPS infusion was used . In thisInduction and preparationThe protocol of LPS infusion represents a slight adaptation of the method reported by Byrne and colleagues  and has LPS infusion2}; blood obtained from the superior vena cava), and central hemodynamic parameters  were obtained. A lipopolysaccharide  solution was initiated using the dosing protocol reported in Table Once fully anesthetized and catheterized, pigs were brought to a euvolemic state using IV PlasmaLyte A  infusion to a pulmonary capillary wedge pressure (PCWP) of 10±1 mmHg, followed by a 15-minute equilibration period. Baseline vital signs , arterial line-derived arterial blood gasses , PAC-obtained venous blood gasses .Data analysisMeasures of central tendency are reported as mean (standard deviation), and comparisons between the two groups were made using paired or unpaired Student’s t-tests, as appropriate. One-way analysis of variance (ANOVA) with post hoc tests was used to assess parameter changes over the course of fluid or pressor administration. A criterion of P≤0.05 was used to denote statistical significance.Most hemodynamic values were directly measured. MPAP was taken as (2/3)(DPAP)+(1/3)(SPAP). SVR was calculated using 80*(MAP-CVP)/CO. CO was taken as the average of three thermodilution-derived measurements. PCWP was obtained at the end of expiration. Arterial waveforms, central venous pressure waveforms, and pulmonary artery waveforms were continually transduced to LabChart 8 for post hoc analysis.-5 to 738 (258) dyn/s/cm-5 and 1121 (196) dyn/s/cm-5 to 759 (342) dyn/s/cm-5, respectively, indicating low-resistance hypotension. Vital signs and central hemodynamic parameters are summarized in Table 2; Group 1 did demonstrate a significant decrease in PCWP , whereas Group 2 did not . Baseline parameters were well matched, though Group 1 had a slightly decreased DPAP and MPAP relative to Group 2.The precipitation of critical hypotension was achieved without mortalities in all 12 pigs, in the two groups. Mean SVRs for the two groups  significantly decreased from 1031 (106) dyn/s/cmDuring the course of four 10 cc/kg boluses, HR decreased (P=0.02), though no changes in systemic or pulmonary blood pressures were noted. PCWP P=0.0003) and CVP (<0.001) were central parameters that increased in response to fluid. Over the range of fluid delivered, CO elevation was observed relative to critical hypotension only upon the post hoc analysis of multiple comparisons, after bolus 2. There was evidence of a trend indicative of increasing CO during the course of the fluid loading (P=0.09). Hemodynamic parameters and select laboratory values obtained during the fluid-loading protocol in Group 1 are summarized in Table  and CVP During the NE infusion protocol, HR significantly increased in Group 1, the fluid-loaded pigs (P=0.003), though was not changed in the NE-only pigs. The final HRs for both groups were not different. Notably, in this model, MAP was not augmented with NE infusion. In both groups, NE administration generated a decrease in CVP, though without significant changes in other central parameters. At the end of the resuscitation protocol, both PCWP  and CVP  were higher in Group 1 than in Group 2. These results are summarized in Table In this investigation, a thorough characterization of a porcine model of endotoxemic hypotension and shock is provided. Moreover, changes in vital signs, central hemodynamic parameters, and key laboratory values indicative of the severity of hypotension and shock are reported during the course of initial fluid resuscitation and during NE-based resuscitation. Clinical paradigms warrant intravenous crystalloid fluid as the initial treatment to increase blood pressure, restore intravascular volume, optimize venous return, and increase perfusion. However, the parameters assessed in this model have not been well characterized in the case where distributive hypotension is treated first with NE, the first-line clinically employed vasopressor. The principal findings are not only that this model of endotoxemia can reliably propagate low-resistance, distributive hypotension but also that fluid pre-loading ultimately increases key parameters indicative of a venous return to the right heart: CVP and PCWP.Multiple other reports of porcine endotoxemia use a constant dose of LPS administration. Endo and colleagues infused LPS at a constant rate of 80 µg/kg/hour. While direct PAC data were not available, interestingly, changes were not observed in HR, MAP, or CVP relative to their baseline values, or a control cohort, during the course of the experiment, while SVR (using PiCCO to estimate CO) only declined after 60 minutes, with normalization by 90 minutes . As thesThis study underscores the sensitivity of PCWP and CVP during fluid- or pressor-based resuscitation from states of distributive shock. PCWP is recognized as a “gold standard” direct measure of fluid status. It is derived via the occlusion of the pulmonary artery with a balloon-tipped port of a PAC and provides an accurate measure of left atrial and left ventricular end-diastolic pressures . Its useThe importance of CO as a surrogate for perfusion, an important endpoint in resuscitation from distributive hypotension and shock, has led to the development of multiple devices to obtain a CO estimation without a PAC. These approaches for the estimation of CO either are operator-dependent (echocardiography) or require an arterial line, intubation, and high tidal volume ventilation for accuracy  . In thisThe degree to which NE-induced CO augmentation is dependent on fluid pre-loading is assessed in a series of pigs to explore whether an up-front NE approach to increasing CO is plausible, a challenge to the current paradigm yet also a question that has prompted national studies. Early NE administration is thought to confer benefits including the prevention of prolonged hypotension, early CO increase, improved microcirculation , and the prevention of fluid overload . Thus, fThis model of swine endotoxemia may be useful for researchers and clinicians, as it allows for the mimicry of the physiology of sepsis and can be used accordingly. It is replicable and relatively cost-effective and allows for the assessment of alternative resuscitation strategies such as a “vasopressor-first” approach. The findings suggest, similar to hemorrhage, that compensatory mechanisms are effectively invoked to preserve CO during the controlled LPS insult, even in cases where pigs are significantly volume-responsive, yet undergo no fluid pre-loading. These data, coupled with the benefits of fluid-restrictive strategies, suggest the need for custom-tailoring resuscitation from distributive shock, as well as the mandate for non-invasive, accurate adjuncts to surrogate for the central parameters PCWP and CO.LimitationsThis model of endotoxemia causes a well-described, initial rapid elevation in pulmonary pressures leading to potential hemodynamic compromise requiring epinephrine, a well-recognized phenomenon whose mitigation with sildenafil has been attempted. Though this elevation in pulmonary pressures is transient and fully reversible, this critical event makes the findings less translatable to the more common human condition of septic shock . AdditioThis porcine model of LPS-induced endotoxemic hypotension with resuscitation can mimic human physiologic perturbations in sepsis. Using this model, a resuscitative approach with NE only generated a lower overall CVP and PCWP, while CO was similar after fluid pre-loading. Further animal and human studies are warranted to optimize resuscitation from distributive shock, balancing excess fluid with the risk of organ malperfusion.


The American Burn Association recommends volume resuscitation at 2-4ml/kg/TBSA; however, in practice, fluid resuscitation often exceeds these goals. Additional strategies used for burn resuscitation include the use of colloid rescue and high dose ascorbic acid (HDAA). In 2018, our institution moved from a fluid resuscitation strategy which included calculating fluid requirements using 4ml/kg/TBSA and HDAA infusion for burns > 30% TBSA to a strategy that calculated fluids using a 2ml/kg/TBSA with the removal of HDAA. Additionally, the guidance for colloid rescue was updated to provide specific time points for evaluation of the need for initiation of this intervention. The primary objective of this study was to compare outcomes of the new institutional resuscitation strategy to the previous one.This was a retrospective cohort study evaluating outcomes for acute burn resuscitation between the previous institutional resuscitation guideline with the updated guideline. This study included adult patients admitted for burn injury with >20% TBSA between August 1, 2016, to September 30, 2021. The primary outcome was a composite safety endpoint which included incidence of acute kidney injury and intra-abdominal hypertension requiring intervention. Acute kidney injury was defined as a serum creatinine increase 1.5 times baseline. Statistical analyses utilized the Mann-Whitney U test for non-normally distributed continuous data and the chi-squared and Fischer’s exact test for categorical data. A p-value of < 0.05 was considered statistically significant.The final analysis included 43 in the pre-group and 52 in the post-group update. Baseline characteristics between the groups were similar. The primary composite safety outcome was non-statistically significantly lower in the post-guideline update group . Total fluid volume administered  and hourly urine output within the first 24 hours  were significantly lower in the post-group. No differences were observed in vasopressor use , vasopressor duration (70.3 hours vs. 50.4 hours p=0.24), or duration of mechanical ventilation .The burn resuscitation guideline update resulted in significantly lower 24 hour- fluid volumes, without negative hemodynamic consequences.The comparison of two resuscitation protocols provides evidence for other institutions to help optimize their resuscitation practice


Glioblastomas are resistant to treatments targeting angiogenic blood vessel development. It is possible that glioblastoma cells are forming vessel-like structures, called vasculogenic mimicry (VM), and contributing to treatment resistance through this process. We aimed to quantify VM in primary and recurrent glioblastoma and to determine whether VM vessels express the pathological vessel marker prostate-specific membrane antigen (PSMA). We found that only a small proportion of vessels in glioblastoma were VM, and that these vessels did not express PSMA. However, the expression of PSMA was decreased in recurrent compared to primary tumours, as was the total vessel density. The potential of VM as a treatment target and its contribution to treatment resistance in glioblastoma require further investigation.p < 0.001). PSMA was expressed by endothelial vessels, and its expression was also decreased in recurrent tumours (p = 0.027). VM was observed in 42.86% of primary tumours and 28.57% of recurrent tumours. VM accounted for only a small proportion of the tumour vasculature and VM density did not differ between primary and recurrent tumours (p = 0.266). The functional contribution of VM and its potential as a treatment target in glioblastoma require further investigation.Vasculogenic mimicry (VM), the ability of tumour cells to form functional microvasculature without an endothelial lining, may contribute to anti-angiogenic treatment resistance in glioblastoma. We aimed to assess the extent of VM formation in primary and recurrent glioblastomas and to determine whether VM vessels also express prostate-specific membrane antigen (PSMA), a pathological vessel marker. Formalin-fixed paraffin-embedded tissue from 35 matched pairs of primary and recurrent glioblastoma was immunohistochemically labelled for PSMA and CD34 and stained with periodic acid–Schiff (PAS). Vascular structures were categorised as endothelial vessels (CD34+/PAS+) or VM (CD34−/PAS+). Most blood vessels in both primary and recurrent tumours were endothelial vessels, and these significantly decreased in recurrent tumours ( Glioblastoma is the most commonly occurring adult primary malignant brain tumour .Despite an aggressive standard treatment approach of maximal safe surgical resection, radiation therapy, and temozolomide (TMZ) chemotherapy, the median survival time for glioblastoma is poor at 14.6 months . AdditioVasculogenic mimicry (VM) is the formation of a functional vascular network by tumour cells . VM was Prostate-specific membrane antigen (PSMA) is a transmembrane glycoprotein expressed in the normal prostatic epithelium, renal tubules, and small intestine ,16. It iSince the extent to which VM occurs in recurrent glioblastoma has not previously been studied, we aimed to determine whether VM vessels were present in recurrent tumours and whether VM density differed between primary and recurrent glioblastoma. We also aimed to assess whether PSMA expression occurred in both angiogenic and VM vessels. This study was approved by the Human Research Ethics Committee of the University of Newcastle (H-2018-0007). Formalin-fixed paraffin-embedded (FFPE) tumour tissue from 35 cases of glioblastoma with matched primary and recurrent tumour tissue was sourced from the Mark Hughes Foundation Brain Cancer Biobank facilitated by the NSW Regional Biospecimen Services (The University of Newcastle). Glioblastoma was diagnosed histologically at the time of primary tumour resection by a Hunter Area Health Service pathologist according to either the 2007 or 2016 World Health Organisation Classification of Tumours of the Central Nervous System criteria. Clinical information available for the cohort included median age at diagnosis (years), patient sex, treatment after primary resection, IDH1 mutation status, MGMT promoter methylation status, recurrent tissue collection timepoint, and median overall survival (days) .® image analysis platform  for analysis.FFPE tissue was sliced into 4 µm sections and processed by the NSW Regional Biospecimen Services for automated IHC using the Ventana Discovery Ultra Staining System . Sections were labelled using pre-diluted rabbit monoclonal PSMA  and mouse monoclonal CD34  as the primary antibodies. Slides were loaded into the instrument and tissue sections were baked to the slides and deparaffinised. Antigen retrieval was performed at pH9/95 °C with an incubation time of 32 min. Blocking was performed before addition of the primary antibody, followed by incubation for 24 min at 36 °C. The appropriate secondary antibody was added , followed by another 24 min incubation period. 3′,3′-diaminobenzadine (DAB) was used as the chromogen. Labelled slides were removed from the instrument. All slides were stained with PAS and counterstained with haematoxylin. Positive and negative control slides were included with each batch of slides labelled by the instrument. Slides were digitised at 400× absolute magnification using the Aperio Digital AT2 Pathology System  and imported into the HALO® to select the area to be analysed. Exclusion annotations were used to outline areas within the tumour that were to be excluded from vessel assessment, such as necrotic tissue. The tiled partitioner function was then used to place 10 boxes of 550 × 500 µm within the annotated region. Boxes were placed at least 550 µm apart and were not placed over any exclusion regions. Where more than 10 boxes were generated, the relevant number of boxes required to reduce to total number to 10 were removed at random by HALO®. The number of endothelial, VM, and “mosaic” vessels were counted within each of the 10 regions per section. Endothelial vessels were CD34+/PAS+, VM vessels were CD34−/PAS+, and vessels that were partially CD34+ and partially CD34− with a PAS+ basement membrane were considered mosaic vessels, as described in previous studies [2.CD34/PAS-labelled sections were used to assess glioblastoma vasculature. An annotation region was drawn around the perimeter of each tumour section in HALO studies ,20. Dens® image analysis platform was used to assess PSMA expression levels. The tumour perimeter was selected, and large areas of necrosis and adjacent normal tissue were manually excluded. Tissue classifier algorithms were trained to recognise PSMA+ labelling , tumour tissue, necrosis, and areas of the slide that did not contain tissue. The Area Quantification algorithm was trained and optimised to detect positive pixel intensities corresponding to PSMA labelling within the tumour. The algorithm was then used to quantify the total tissue area analysed for each tumour and the percentage of the tumour that was weakly, moderately, and strongly labelled for PSMA. PSMA expression values were calculated as an H-score for each tumour section using the equation: H-score = (1 × % of weakly labelled tissue) + (2 × % of moderately labelled tissue) + (3 × % of strongly labelled tissue). HALOp-value < 0.05 was considered statistically significant for all tests. Datasets were tested for normality using the Shapiro–Wilk test. Two-tailed Wilcoxon matched-pairs signed rank tests were used to assess median differences in total vessel density and densities of endothelial, VM, and mosaic vessel subsets between primary and recurrent tumour groups. A one-tailed Wilcoxon matched-pairs signed rank test was used to determine whether PSMA expression significantly decreased in the recurrent tumour group. Kendall’s tau-b correlations were run to determine the relationship between vessel densities, PSMA expression, and clinical characteristics. Kaplan–Meier survival analyses with log rank tests were used to determine whether there were differences in the overall survival (OS), progression-free survival (PFS), or post-progression survival distributions when tumours were grouped as being VM+/VM− or having above or below median PSMA expression. OS was defined as the time in days between the date of primary surgery and date of death, or last known follow-up for censored cases. PFS was defined as the time in days between the date of primary surgery and date of recurrent surgery, and post-progression survival was defined as the time in days from the date of recurrent surgery until date of death. Descriptive statistics are reported as median values for tests of group differences and survival analyses. Statistical analyses were performed using SPSS Statistics  or GraphPad Prism . A A total of 35 cases with matched primary and recurrent glioblastoma samples were included in this study. Twenty patients (57.14%) were male and 15 (42.86%) were female. The median age at diagnosis was 59 years (range 23–81 years) and the median OS time was 493 days (range 57–2531 days). Additional demographic and clinical information is summarised in Immunohistochemical labelling for CD34 and staining with PAS were used to identify endothelial, VM, and mosaic vessels in glioblastoma tissue sections . Vessels2) to recurrent (41.67 vessels/mm2) tumours was statistically significant  compared to primary (86.98 vessels/mm2) glioblastomas  and recurrent (1.32 vessels/mm2) groups  demonstrated a decrease in total vessel density at recurrence, and the decrease in total vessel density from primary (88.30 vessels/mmn = 20) had a median OS time of 514 days, which was longer than the median OS time of 445 days for patients with VM+ tumours (n = 15). However, the survival distributions of the two groups were not significantly different (χ2 (1) = 0.381, p = 0.537) (n = 25) had a longer median OS time of 553 days compared to the median OS time of 434 days for the VM+ recurrent group (n = 10). Again, the difference in OS distributions was not significant (χ2 (1) = 3.552, p = 0.060) (2 (1) = 4.830, p = 0.028), where the median survival of the VM− group  was longer than that of the VM + group   A. When s= 0.060) B. Howeve; n = 8) C. PFS di; n = 8) . z = −1.925, one-tailed p = 0.027) (To determine which type(s) of vessels expressed PSMA in glioblastoma, serial sections of tissue were labelled by DAB IHC for PSMA or CD34 and stained using PAS. Vascular areas of tumour tissue that were PSMA+ were also CD34+ on the subsequent section, indicating that PSMA is expressed by endothelial vessels, not VM, in glioblastoma . We then= 0.027) . n = 18) had a median OS time of 501 days, which was not significantly different from the OS time of 493 days for the below-median PSMA group  = 0.188, p = 0.665)  was longer than for cases with below-median PSMA expression  = 3.860, p = 0.049) (2 (1) = 0.143, p = 0.705)  A. The me= 0.049) B. Howeve= 0.705) C. PFS an= 0.705) . b = 0.343, p = 0.009). No other significant correlations between vessel densities and clinical features were observed . All correlations between densities of different vessel types are shown in b = 0.175, p = 0.143) or recurrent  glioblastoma. The complete correlation matrix is presented in We next determined whether there were correlations between densities of any of the observed vessel types, in either primary or recurrent tumours, and clinical characteristics such as age at diagnosis and OS time. There was a statistically significant moderate positive correlation between VM vessel density in the primary tumour and age at diagnosis . In The reduction in overall vessel density at recurrence compared to primary glioblastoma was attributed to a significant decrease in the density of endothelial vessels, which accounted for most of the tumour vasculature. A decrease in CD34+ vessel density in recurrent glioblastoma has been previously reported ,26, withLabelling for the endothelial cell marker CD34 through immunohistochemistry (IHC) and staining with PAS is the most frequently used method of identifying VM vessels in glioblastoma tissue . Using tAlthough we report a smaller proportion of VM vessels, our results are in agreement with those of a previous study, which also demonstrated that VM vessels represent a minor component of the glioblastoma vasculature . Liu et Despite VM making a minor contribution to the overall vascular density in glioblastoma, a shorter overall survival time has been reported for glioblastoma patients with VM+ primary tumours ,14. We aIn addition to completely CD34− vessels, we observed vessels that were partially CD34+ in a subset of both primary and recurrent glioblastomas. We categorised these as “mosaic” vessels, consistent with prior reports of these vessels in glioblastoma ,20. One PSMA is expressed by the vasculature of numerous tumour types. In agreement with our results, the expression of PSMA in endothelial-cell-lined vessels in glioblastoma has been previously reported ,26. In tWhile we did not observe PSMA+ VM structures in our glioblastoma cases, the possibility of PSMA expression by glioblastoma-derived vasculature cannot be entirely excluded. PSMA is expressed not only by vessels within tumours, but also by a small proportion of glioblastoma cells, which, in addition to VM, may also undergo the process of endothelial transdifferentiation in order to contribute to vessel formation ,40. In nChanges that occur after treatment in recurrent glioblastoma extend to aspects of the tumour microenvironment, including the tumour vasculature. These changes include a decrease in endothelial vessel density and decreased expression of PSMA, suggesting a reduced dependence on tumour angiogenesis. Categorical assessment of VM presence at recurrence suggested an association between VM and shorter post-progression survival. However, VM accounted for a minor proportion of the tumour vasculature in both the primary and recurrent setting, and the extent to which VM makes a functional contribution to the overall vasculature requires further study in order to determine whether VM is a relevant treatment target.


Lactate is not only an endpoint of glycolysis but is gradually being discovered to play the role of a universal metabolic fuel for energy via the ‘lactate shuttle’ moving between cells and transmitting signals. The glycolytic‐dependent metabolism found in tumours and fast‐growing cells has made lactate a pivotal player in energy metabolism reprogramming, which enables cells to obtain abundant energy in a short time. Moreover, lactate can provide favourable conditions for tumorigenesis by shaping the acidic tumour microenvironment, recruiting immune cells, etc. and the recently discovered lactate‐induced lactylation moves even further on pro‐tumorigenesis mechanisms of lactate production, circulation and utilization. As with other epigenetic modifications, lactylation can modify histone proteins to alter the spatial configuration of chromatin, affect DNA accessibility and regulate the expression of corresponding genes. What's more, the degree of lactylation is inseparable from the spatialized lactate concentration, which builds a bridge between epigenetics and metabolic reprogramming. Here, we review the important role of lactate in energy reprogramming, summarize the latest finding of lactylation in tumorigenesis and try to explore therapeutic strategies in oncotherapy that can kill two birds with one stone. Lactate is not only an endpoint of glycolysis but is gradually being discovered to play the role of a universal metabolic fuel for energy via the ‘lactate shuttle’ moving between cells and transmitting signals. The glycolytic‐dependent metabolism found in tumours and fast‐growing cells has made lactate a pivotal player in energy metabolism reprogramming, which enables cells to obtain abundant energy in a short time. Moreover, lactate can provide favourable conditions for tumorigenesis by shaping the acidic tumour microenvironment, recruiting immune cells, etc., and the recently discovered lactate‐induced lactylation moves even further on pro‐tumorigenesis mechanisms of lactate production, circulation and utilization. As with other epigenetic modifications, lactylation can modify histone proteins to alter the spatial configuration of chromatin, affect DNA accessibility and regulate the expression of corresponding genes. What's more, the degree of lactylation is inseparable from the spatialized lactate concentration, which builds a bridge between epigenetics and metabolic reprogramming. Here, we review the important role of lactate in energy reprogramming, summarize the latest finding of lactylation in tumorigenesis and try to explore therapeutic strategies in oncotherapy that can kill two birds with one stone. Study shows that a small number of mutations in genes can exhibit profoundly altered DNA methylation patterns.In addition to the disruption of the normal pattern of epigenetic modification such as global hypomethylation of DNA, the occurrence of abnormal epigenetic mutations can also lead to the occurrence of disease.Epigenetic modifications, including a wide range of post‐translational modifications (PTMs) on histone and non‐histone proteins, integrate environmental cues that feed back into downstream cellular responses through regulatory gene expression.In 2019, Zhang et al. discovered a brand new epigenetic modification called lactylation on lysine residues that directly stimulates gene transcription from chromatin, through a mass shift from mass spectrometry that matched with a lactyl group.Collectively, lactate‐induced lactylation, the epigenetic modification that is metabolic stress‐related, links the high‐lactate characteristics of tumour metabolism with tumorigenesis from a new perspective.2A major hallmark of cancer is metabolic reprogramming.Not only in the tumour microenvironment but also lactate in the human body has long been proven to be not just a product of hypoxia, but can be continuously formed and utilized under aerobic conditions. The production and utilization of lactate not only reflect the metabolism within the cells but also signals through the lactate shuttle between cells.Some studies have shown that aerobic glycolysis is performed by the cancer‐associated fibroblasts (CAFs) recruited by the tumour, which thus extrudes lactate to ‘feed’ neighbouring cancer cells. The expression of MCT4, a transporter that controls lactate efflux, in CAFs and the high expression of MCT1, a transporter involved in lactate uptake, in breast cancer cells support these ideas. This ‘metabolic coupling’ between the tumour‐associated stroma and adjacent epithelial cancer cells provides the impetus for the growth and metastasis of cancer cells.However, there is another recent finding that may give a different idea. The hypoxic cell population in the tumour microenvironment uses glucose for Warburg‐like metabolism, and the ensuing large amount of lactate is transported via the lactate shuttle to the adjacent normal oxygen‐supplying cell population for oxidative phosphorylation metabolism (OXPHOS metabolism).The above two views seem to indicate that there are different ‘metabolic couplings’ in the complex and diverse tumour microenvironment, and there is still no universal conclusion on who is the bearer of lactate production, but what shapes such metabolic reprogramming have been successively reported in recent years. This tumour‐promoting metabolic switch mediates by transforming growth factor signalling, activating HIF‐1α‐transcription, oncogene activation or tumour suppressor gene loss and maintaining tumour cell survival and development in the harsh tumour microenvironment.As mentioned above, in the tumour microenvironment, lactate is mass‐produced, accumulated and promoted tumorigenic through a variety of functions, one of which is reshaping the tumour microenvironment.3As more and more studies have been reported, many metabolites can become substrates or cofactors of acylating enzymes and act on epigenetic modification. Fluctuations in metabolite concentrations will directly affect the extent of epigenetic modification, this connection can be spatial, which means the transfer of enzymes or metabolites, or changes of them in spatial regions can affect the level of modification in the corresponding region.Cell chromatin is composed of DNA and histones, both of which can be modified epigenetically, affecting the configuration of chromosomes and, thus, acting as gene regulation. Epigenetic modifications on both DNA and histones regulate the enzymes of the corresponding metabolic pathways, which, in turn, influence epigenetic modification.Acetylation is a chemical reaction in which acetyl‐CoA serves as an acetyl‐group donor, lysine acetyltransferases (KATs) and histone acetyltransferases (HATs) as catalytic enzymes, which are also known as writers.Interestingly, recent studies have found that there is a complex crosstalk between the newly discovered histone modification lactylation and acetylation, which may shed some light on their role, separately and synergistically, in tumours and corresponding treatment strategies. Both lactylation and acetylation tend to occur on lysine (Lys) residues, and p300 in the HATs family has also been found to be the main ‘writer’ enzyme for lactylation.44.1Lactylation was initially found at lysine in histones, which is also known as Kla. After the histone lactylation was discovered, Zhang et al. demonstrated through further research that the lactylation modification also increased in a dose‐dependent manner with the addition of glucose dose, which was further demonstrated by tracking glucose 13C‐labelled atoms. Drug‐mediated inhibition and promotion of glycolysis, respectively, lead to a decrease and increase in global Kla amounts, which means that lactylation levels are inextricably linked to local lactate concentrations.Kla has been found to play a regulatory role in physiological processes such as activating transcription, promoting cell reprogramming, promoting pulmonary fibrosis and promoting macrophage polarization.With the deepening of its research, as well as the breakthrough of lactated protein analysis technology,4.2Lactate‐induced lactylation modulates and creates a favourable tumour microenvironment and promotes the survival and progression of tumour.Lactate itself has long been found to promote tumour proliferation by inducing VEGF expression and TAM polarization to an M2‐like phenotype. Tumour‐derived lactate signalling activates macrophages via HIF1α to reach a tumour‐promoting state characterized by upregulated expression of Arg 1 and VEGF.β signalling in Treg cells, and patients with hepatocellular carcinoma with a low degree of MOESIN lactylation in Treg cells were more sensitively responding to anti‐PD‐1 treatment. Combination therapy with anti‐PD‐1 and lactate dehydrogenase inhibitors has a stronger anti‐tumour effect than anti‐PD‐1 alone, which also indicates that lactylation has great potential as a target for combination therapy.TIMs play an important role in tumour immune escape, and lactylation enriched in the promoter of methyltransferase‐like 3 (METTL3) region drives the high expression of METTL3, which, in turn, strengthens the immunosuppressive capacity of TIMs through the METTL3/m6A/JAK1/STAT3 axis.In addition to playing an important role in remodelling the microenvironment, lactylation has also been found to play an important role in the regulation of the pluripotency of cells. Gli‐like transcriptional factor 1 (Glis1) binds to promotors of somatic genes and glycolytic genes in the early stage of reprogramming and triggers the epigenome–metabolome–epigenome cascade, which further facilitates cellular reprogramming from senescent cells into pluripotent cells.Lactylation can work with other epigenetic modifications to co‐act in tumorigenesis. In ocular melanoma, lactylation signals were also found to be significantly enriched in the YTHDF2 (YTH N6‐methyladenosine RNA binding protein 2) promoter region and YTHDF2, one of the m6A code readers, has been reported to function as an oncogene in a variety of tumours.β (platelet‐derived growth factor receptor β) signalling, which, in turn, facilitates histone lactylation, thus forming a positive feedback loop of pro‐tumorigenesis in ccRCC.By directly regulating gene expression, lactate‐induced lactylation can act on key tumorigenesis pathways, thereby promoting tumorigenesis and metastasis. Lactylation was found upregulated in clear cell renal cell carcinoma (ccRCC), triggered by inactive von Hippel–Lindau (VHL), which is widely recognized as an essential part of ccRCC formation.5Lactate is a core energy metabolism substrate that plays the role of a key molecule for metabolism between cells in the tumour microenvironment. Some tumour cells and CAFs undergoing metabolic reprogramming can quickly obtain a large amount of energy by aerobic glycolysis and transport the lactate produced in large quantities to other cells in the microenvironment through ‘lactate shuttle’, efficiently supplying substrates for energy‐producing. As a result, the concentration of lactate in the microenvironment and related cells significantly increases, which not only directly shapes the tumour‐promoting acidic microenvironment but also provides a substrate for cellular lactylation in the tumour‐related microenvironment. Studies have shown that the occurrence of lactylation is related to spatial lactate concentration, and multiple key lactylation sites have been detected in the tumour microenvironment, which can recruit tumour‐related immune cells, reshape the microenvironment and cooperate with other epigenetic modifications to promote tumorigenesis, progression, and even directly act on the gene expression of tumour‐related key pathways. Collectively, In the tumour microenvironment, the production, circulation and utilization of lactate have become the ‘right hand’ of tumours in both energy metabolism and epigenetic modification, which plays a role in facilitating tumour onset and progression. Therefore, whether targeted lactylation can be used as an effective means of cancer treatment, or whether targeted lactate production can kill two birds with one stone, while improving the tumour microenvironment, preventing and improving lactylation modification to combat tumours, the exploration of these problems is promisingly moving towards potentially powerful tumour treatment strategies.Yi Qin conceived of the presented idea; Ting Wang, Zeng Ye, Zheng Li, De‐sheng Jing and Gui‐xiong Fan wrote the manuscript and prepared the figure and tables; Meng‐qi Liu, Qi‐feng Zhuo and Shun‐rong Ji searched the literature and collected the references; Yi Qin, Xiao‐wu Xu and Xian‐jun Yu supervised the project and critically reviewed and edited the manuscript. All authors read and approved the final manuscript.This work was supported by grants from Shanghai Municipal Science and Technology Commission (20ZR1471100), National Natural Science Foundation of China , Shanghai Municipal Science and Technology Major Project (21JC1401500), Scientific Innovation Project of Shanghai Education Committee (2019‐01‐07‐00‐07‐E00057), Clinical Research Plan of Shanghai Hospital Development Center (SHDC2020CR1006A) and Xuhui District Artificial Intelligence Medical Hospital Cooperation Project (2021–011).The authors declare that they have no conflict interests.