SURG-69. Diffuse Intrinsic Pontine Gliomas in Adults: A Prospective Single-Institute Study

Abstract INTRODUCTION Adult DIPG comprises only 1-2% of adult brain tumours; it is important to discuss this entity in adults because, with whatever limited literature we have, the disease appears to be a different entity than pediatric DIPG. In this study, we will explore the clinic-radiological, surgical, histopathological, and genetic aspects of the disease and their impact on prognosis. METHOD This is a prospective study of all adult patients with diffuse intrinsic pontine glioma from June 2019 to April 2023. Clinical, radiological, histology, and molecular features were reviewed and prognostic factors for overall survival was analysed for all patients. RESULTS We included 47 adult patients: 20 with H3K27M alterations, 15 without H3K27M alterations, and 12 without a biopsy. The median age of our study population is 29 years. Median KPS was 90. Cranial nerve palsy was the most common presenting complaint. Hydrocephalus requiring cerebrospinal fluid (CSF) diversion was present in 8 patients (17%). Lesion biopsy was performed in 35 patients (74.5%), and exophytic component decompression was done in 4 patients (8.5%). Four patients were lost to follow-up. Adjuvant therapy was received by 25 patients (58.1%). Radiotherapy was the only significant prognostic indicator of overall survival (p-value<0.01). There were 12 long-term survivors in our study, but we did not find any significant survival prognostic indicator among this group. Patients with non-H3K27 M altered DIPG had a significantly better survival rate than those with H3K27M-altered glioma (p-value < 0.01). CONCLUSION Adult DIPG behave differently from pediatric DIPG due to differences in the histopathological diagnosis spectrum and hence needs to be assessed in depth for better prognostication of patients.