Predicting response to chemotherapy in neuroblastoma using deep learning: A report from the International Neuroblastoma Risk Group.
10039 Background: Metaiodobenzylguanidine (MIBG) scans are a radionucleotide imaging modality used to evaluate neuroblastoma stage at diagnosis and also determine disease response following therapy. Curie scoring is used to semi quantitatively assess disease burden from an MIBG scan on a scale from none (0) to widespread throughout the body (30) While a Curie score =2 after six cycles of induction chemotherapy has been shown to be prognostic of outcome, there is no established correlation between diagnostic Curie score and outcome. Deep learning models, such as convolutional neural networks (CNN) have been shown to learn generalizable patterns within images for successful classification of metastases and detection of multiple adult cancers. We hypothesized a CNN could be developed to predict response to induction chemotherapy, a proxy for outcome, using diagnostic MIBG scans. Methods: DICOM MIBG scans and associated clinical data from a Children's Oncology Group (COG) pilot study for children diagnosed with high risk neuroblastoma (ANBL12P1; NCT1798004) were deidentified and linked to clinical data by the Pediatric Cancer Data Commons and obtained from the International Neuroblastoma Risk Group Data Commons. Patients were defined as having a poor response to induction chemotherapy if their Curie score after four cycles of induction chemotherapy was =2. An independent external validation cohort was comprised of 29 images from 26 high risk patients treated at the University of Chicago with clinically annotated diagnostic and post cycle six induction DICOM MIBG scans. The CNN was trained using 2D whole body MIBG scans obtained at diagnosis. We developed the CNN using a transfer learning approach using the Xception architecture as the base layer. Hyperparameter optimization was performed using an 80% 20% train validation strategy. Model performance was evaluated using area under the receiver operating characteristic curve (AUROC) Results: Among 146 patients with high risk neuroblastoma enrolled on ANBL12P1, 104 had available diagnostic and end induction MIBG scans. There were no differences in clinical or biological characteristics between included and excluded patients. The base model CNN was able to predict which patients had a poor response to induction chemotherapy with an AUROC of 0.72 in the validation set from the ANBL12P1 cohort. Additionally, the CNN was able to predict patient response to therapy with an AUROC of 0.64 in an independent external dataset from University of Chicago. Conclusions: Our study suggests it is feasible to apply machine learning of diagnostic MIBG scans to predict response to chemotherapy for high risk neuroblastoma patients. Given these promising results, further work to improve AUROC and performance within larger datasets is ongoing.