Evaluating Immunotherapy Responses in Neuro-Oncology for Glioblastoma and Brain Metastases: A Brief Review Featuring Three Cases.

Abstract

Introduction: Recent advancements in immunotherapy have offered new possibilities for treating aggressive glioblastoma (GBM) and brain metastases. However, evaluating treatment responses remains complex, prompting the development of the immunotherapy-specific Response Assessment in Neuro-Oncology (iRANO) criteria. Herein, we present case reports illustrating the intricacies of interpreting imaging changes post-immunotherapy, emphasizing the need for a comprehensive approach to assessing treatment effectiveness.

Case reports: Case 1 discusses a 41-year-old male with GBM, highlighting the challenges of differentiating tumor progression from treatment-induced pseudoprogression. Case 2 discusses a 45-year-old female with brain metastatic malignant melanoma, presenting radiological evidence of progressive disease while undergoing nivolumab treatment. Case 3 discusses a 37-year-old male with GBM, where radiological evidence indicates progressive disease while receiving pembrolizumab treatment.

Management and outcomes: In case 1, we discussed the challenges of distinguishing true tumor progression from treatment-induced pseudoprogression, leading to the continuation of the same treatment due to pseudoprogression. In case 2, post-surgery pathology revealed radionecrosis and treatment-related changes, guiding the continuation of nivolumab therapy. Case 3 involved a pathologically confirmed progression, and the patient received best supportive care due to his performance status.

Discussion: Despite aggressive treatment regimens, the prognosis for GBM patients remains poor, underscoring the necessity for innovative therapeutic strategies. Immunotherapy holds promise in reshaping the treatment landscape for GBM and brain metastases, but further research and refinement of assessment criteria are crucial. Throughout our cases, we discuss the iRANO criteria, developed to overcome the limitations of the RANO criteria in capturing immunotherapy responses, particularly pseudoprogression.