Diffuse pontine glioma (DPG): shorter or longer treatment time?

Diffuse intrinsic pontine glioma is a lethal disease with a median overall survival (OS) of less than one year. Currently, no curative treatment exists, and radiotherapy primarily aims for symptom palliation. Hypofractionated radiotherapy (HR) has been proposed to enhance quality of life through shorter treatment duration, fewer hospital visits, and reduced costs, particularly in low- and middle-income countries (LMICs). However, many LMIC institutions continue to use 54 Gy in 30 fractions. The study aims to identify patients who may benefit from HR.

We reviewed data from MAHAK patients treated between April 2010 and February 2020. Diagnosis was based on clinical symptoms and MRI imaging; biopsy was not mandatory.

Among 108 identified patients, 34(32%) underwent a biopsy, with high-grade glioma or glioblastoma diagnosed in 18(53%). H3K27M mutation was found in two patients, while others were not evaluated. No seeding was detected at diagnosis. Thirty-one patients (29%) received 50-54 Gy using normal fractionation, while the remainder received HR. Median OS was 9.6 months (range 1-67). No significant impact of fractionation was observed. Seventy-eight (72%) patients received chemotherapy, which showed no benefit. Eleven patients received re-irradiation at progression, showing a post-progression OS of 6 months. Poor-risk factors included age over 4 years, symptom duration < 3months, simultaneous triad signs, and absence of hydrocephalus (p < 0.05).

Given their shorter life expectancy, poor-risk patients may benefit from HR. We propose a scoring system based on prognostic factors to guide decisions between HR and normal fractionation.