Pediatric diffuse intrinsic pontine gliomas- a prospective observational study from a tertiary care neurosurgical center.

Introduction: Diffuse intrinsic pontine glioma (DIPG) in children comprises 80% of brainstem gliomas. In 2021, 5th edition of WHO CNS tumor classification defined H3K27M altered diffuse midline gliomas (DMGs) which replaced this entity. Lesion location precludes resection and the only current option available is radiotherapy. Patient age, duration of symptoms, histone subtype mutation etc. may helpl in prognostication but the disease remains incurable with a median overall survival of 9-12 months.

Method: This is a prospective observational study from a tertiary health care center in a low to middle-income country. We included patients with DIPG (radiological and/or histopathological H3K27M altered) from June 2018 to April 2023. Clinical, radiological, histology, and molecular features were reviewed and prognostic factors for 3 months, 6 months, and overall survival was analysed for all patients.

Results: We included 92 pediatric patients. The median age of our study population was 8.5 years. Median LPS was 80. Cranial nerve palsy was the most common presenting complaint. Hydrocephalus requiring CSF diversion was present in 38 patients (41.3%). Lesion biopsy was performed in 36 patients (39.1%) and exophytic component decompression was done in 11 patients (11.9%). Seven patients were lost to follow-up. Adjuvant therapy was received by 51 patients (51/85, 60%). Radiotherapy was the only significant prognostic indicator of 3 months, 6 months, and overall survival (HR: 0.39). The presence of necrosis on histopathology was also an indicator of poor prognosis (HR: 2.38). There were 7 long-term survivors in our study but we did not find any significant survival prognostic indicator amongst this group.

Conclusion: Conventional adjuvant therapy has not proven of much benefit. With the advancement in molecular understanding of the entity, there is an upsurge in the development of targeted therapy but with no promising results so far. In this study, we have attempted to explore the prognostic factors and unique challenges we face in a resource-limited setting against this disease.