Treating<unk>  is difficult due to several complicating factors: * The tumor cells are resistant to conventional therapies. * The brain is susceptible to damage from conventional therapy. * The brain has a limited capacity to repair itself. * Many drugs cannot cross the blood–brain barrier to act on the tumor. Treatment of primary brain tumors consists of palliative (symptomatic) care and therapies intended to improve survival. Symptomatic therapy Supportive treatment focuses on relieving symptoms and improving the patient's neurologic function. The primary supportive agents are anticonvulsants and corticosteroids. * Historically, around 90% of patients with<unk>  underwent anticonvulsant treatment, although only an estimated 40% of patients required this treatment. Recently, neurosurgeons have been recommended that anticonvulsants not be administered prophylactically, and should wait until a seizure occurs before prescribing this medication. Those receiving phenytoin concurrent with radiation may have serious skin reactions such as erythema multiforme and Stevens–Johnson syndrome. * Corticosteroids, usually dexamethasone, can reduce peritumoral edema (through rearrangement of the blood–brain barrier), diminishing mass effect and lowering intracranial pressure, with a decrease in headache or drowsiness. Surgery Surgery is the first stage of treatment of<unk> . An average<unk>  tumor contains 1011 cells, which is on average reduced to 109 cells after surgery (a reduction of 99%). Benefits of surgery include resection for a pathological diagnosis, alleviation of symptoms related to mass effect, and potentially removing disease before secondary resistance to radiotherapy and chemotherapy occurs. The greater the extent of tumor removal, the better. In retrospective analyses, removal of 98% or more of the tumor has been associated with a significantly longer healthier time than if less than 98% of the tumor is removed. The chances of near-complete initial removal of the tumor may be increased if the surgery is guided by a fluorescent dye known as 5-aminolevulinic acid.<unk>  cells are widely infiltrative through the brain at diagnosis, so despite a "total resection" of all obvious tumor, most people with<unk>  later develop recurrent tumors either near the original site or at more distant locations within the brain. Other modalities, typically radiation and chemotherapy, are used after surgery in an effort to suppress and slow recurrent disease. Radiotherapy Subsequent to surgery, radiotherapy becomes the mainstay of treatment for people with<unk> . It is typically performed along with giving temozolomide. A pivotal clinical trial carried out in the early 1970s showed that among 303<unk>  patients randomized to radiation or nonradiation therapy, those who received radiation had a median survival more than double those who did not. Subsequent clinical research has attempted to build on the backbone of surgery followed by radiation. On average, radiotherapy after surgery can reduce the tumor size to 107 cells. Whole-brain radiotherapy does not improve when compared to the more precise and targeted three-dimensional conformal radiotherapy. A total radiation dose of 60–65 Gy has been found to be optimal for treatment.<unk>  tumors are well known to contain zones of tissue exhibiting hypoxia, which are highly resistant to radiotherapy. Various approaches to chemotherapy radiosensitizers have been pursued with limited success . , newer research approaches included preclinical and clinical investigations into the use of an oxygen diffusion-enhancing compound such as trans sodium crocetinate as radiosensitizers, and a clinical trial was underway. Boron neutron capture therapy has been tested as an alternative treatment for<unk> , but is not in common use. Chemotherapy Most studies show no benefit from the addition of chemotherapy. However, a large clinical trial of 575 participants randomized to standard radiation versus radiation plus temozolomide chemotherapy showed that the group receiving temozolomide survived a median of 14.6 months as opposed to 12.1 months for the group receiving radiation alone. This treatment regimen is now standard for most cases of<unk>  where the person is not enrolled in a clinical trial. Temozolomide seems to work by sensitizing the tumor cells to radiation, and appears more effective for tumors with MGMT promoter methylation. High doses of temozolomide in high-grade<unk> omas yield low toxicity, but the results are comparable to the standard doses. Antiangiogenic therapy with medications such as bevacizumab control symptoms, but do not appear to affect overall survival in those with<unk> . The overall benefit of anti-angiogenic therapies as of 2019 is unclear. In elderly people with newly diagnosed<unk>  who are reasonably fit, concurrent and adjuvant chemoradiotherapy gives the best overall survival but is associated with a greater risk of haematological adverse events than radiotherapy alone. Cannabinoids The efficacy of cannabinoids (cannabis derivatives) is known in oncology (through capsules of tetrahydrocannabinol (THC) or the synthetic analogue nabilone), on the one hand to combat nausea and vomiting induced by chemotherapy, on the other to stimulate appetite and lessen the sense of anguish or the actual pain. Their ability to inhibit growth and angiogenesis in malignant<unk> omas in mouse models has been demonstrated. The results of a pilot study on the use of THC in end-stage patients with recurrent<unk>  appeared worthy of further study. A potential avenue for future research rests on the discovery that cannabinoids are able to attack the neoplastic stem cells of<unk>  in mouse models, with the result on the one hand of inducing their differentiation into more mature, possibly more "treatable" cells, and on the other hand to inhibit tumorigenesis. Other procedures Alternating electric field therapy is an FDA-approved therapy for newly diagnosed and recurrent<unk> . In 2015, initial results from a phase-III randomized clinical trial of alternating electric field therapy plus temozolomide in newly diagnosed<unk>  reported a three-month improvement in progression-free survival, and a five-month improvement in overall survival compared to temozolomide therapy alone, representing the first large trial in a decade to show a survival improvement in this setting. Despite these results, the efficacy of this approach remains controversial among medical experts. However, increasing understanding of the mechanistic basis through which alternating electric field therapy exerts anti-cancer effects and results from ongoing phase-III clinical trials in extracranial cancers may help facilitate increased clinical acceptance to treat<unk>  in the future. A Tel Aviv University study showed that pharmacological and molecular inhibition of the P-selectin protein leads to reduced tumor growth and increased survival in mouse models of<unk> . The results of this research could open to possible therapies with drugs that inhibit this protein, such as crizanlizumab.
Glioblastoma
Ameloblastoma
Glioma
Medulloblastoma
Hemangioblastoma
Gliosarcoma
Astrocytoma
Gliosis