Integrating Quantitative Radiomics in De-intensification Treatment for Oropharyngeal Carcinoma.

Abstract

PURPOSE/OBJECTIVE(S)\nDeintensification for early-stage oropharyngeal carcinoma includes surgery +/- adjuvant radiation therapy without the use of concurrent chemotherapy. Pathologic findings of nodal extracapsular extension (ECE), however, obligate the use of postoperative concurrent chemotherapy in these patients. The purpose of this study was to develop a robust predictive model for ECE using quantitative radiomics.\n\n\nMATERIALS/METHODS\nBetween 2016 and 2020, 81 patients with newly diagnosed resectable oropharyngeal carcinoma underwent upfront transoral robotic surgery and neck dissection at our institutions. In all these patients, high-resolution CT scans were done preoperatively and were concluded to have no evidence of ECE by experienced head and neck radiologists. Eight five percent of tumors were HPV-positive. Median age was 63 years. Radiomics features (107 features) from the primary and extended nodal regions (1-3 mm extension) were extracted to generate predictive models. Two feature selection approaches were evaluated: Minimum Redundancy Maximum Relevance (MRMR) and Linear Discriminant Analysis (LDA). Logistic regression, decision tree, and random forests classifier were chosen for our analysis.\n\n\nRESULTS\nThirty eight percent of patients were found to have ECE in at least one of the nodes, and therefore received concurrent chemoradiation postoperatively. There was a total of 119 pathological positive nodes. Of these positive nodes, 31 nodes were found to have ECE with a ECE of less than 1 to 10mm. Five-fold stratified cross-validation was used for evaluation. A 96% accuracy (0.95 AUC, 0.96 recall) was achieved from the primary node without extension, using LDA feature selection. An improved result of 97% accuracy (0.96 AUC, 0.97 recall) was obtained with the 3mm extension. MRMR attained the maximum accuracy of 77% (0.64 AUC, 0.36 recall) with the 3mm extension.\n\n\nCONCLUSION\nQuantitative radiomics allows a robust prediction of ECE, thereby optimizing de-intensification therapy for oropharyngeal carcinoma.