Radiomics for Differentiation of the Posterior Fossa Pilocytic Astrocytoma Versus Hemangioblastomas in Adults. A Pilot Study

Purpose:Both pilocytic astrocytoma (PA) and hemangioblastoma (HB) are common primary neoplasms of the posterior fossa with similar radiological manifestations. This study was conducted to evaluate the role of radiomics in differentiating these two conditions in adults. Materials and Methods:After a retrospective search of our institutional imaging archive, adult patients with a known diagnosis of PA or HB were included. We reviewed each patient’s most recent preoperative brain magnetic resonance imaging (MRI). The solid enhancing nodule of each lesion on post-contrast T1 sequence was manually segmented. Multiple radiomic features were then extracted from each nodule using the Pyradiomic library. Subsequently, the most predictive features were identified by feature selection models. Following this, different machine learning (ML) models were constructed based on these selected features to classify lesions as PA or HB. Finally, we evaluated the performance of each model by leave-one-out cross-validation. Results:With inclusion and exclusion criteria, 34 enhancing PA nodules and 39 HB nodules were selected. A total of 115 features were extracted from each enhancing nodule. Twelve characteristics were detected as most predictive of histopathological diagnosis. Among various ML models, the neural network had the best performance in differentiating these two conditions with an AUC of 0.9 and an accuracy of 82%. Conclusions:In this retrospective study, radiomic MRI techniques demonstrated high performance in distinguishing adult posterior fossa PA from HB. Future development of radiomic models may advance presurgical diagnosis of these two conditions when added to routine clinical practice and thus improve patient management.