RADT-31. EMBRACING HYPOFRACTIONATED RADIOTHERAPY FOR GLIOBLASTOMA IN A RESOURCE CONSTRAINED SETTING

Abstract BACKGROUND Various hypofractionated schedules of radiation have been tried in glioblastoma with limited success. Though the shorter fractionation is appealing and there is evidence (since 2017) to use the 40Gy in 15 fractions regime in the elderly, the fear of toxicity limits its use, especially in the developing nations. We have tried this regime in younger patients (not eligible for supportive care alone) who had a poor Performance status or if only a biopsy had been performed. METHODS 25 patients treated for glioblastoma from 2017 to 2023 using 4000cGy delivered in 15 fractions were included in the study. The patient details were obtained retrospectively from the medical records and the Eclipse Treatment Planning system. RESULTS There were 16 males and 9 females. Median age was 62 years (range 52 to 77 years). 56% of the patients had an ECOG performance score of 3; and the rest 2. 12 lesions were on the Right side, 9 in the left and the rest extended across the midline. Surgery was limited to biopsy alone in 8; almost as many (n=7) had a Near Total Resection; the rest underwent decompression. Surprisingly, almost half the patients were MGMT unmethylated. 16 patients were on steroids either during or after radiation. All 25 maintained their Performance Status and completed radiation as planned. The mean GTV Volume - 53.48 cc (Range 6-201). Dmax was never above 103%; Brainstem and Optic Apparatus Dmax were also kept below 100%. In the majority, 3 beams of mixed energy were used. 19 patients received both Concurrent and adjuvant temozolomide; only adjuvant was given to 6. The median overall survival was 7.7 months (range 2-60.6 months) and the Disease free survival was 7.5 months (Range 1-60.5 months). CONCLUSIONS Hypofractionated radiotherapy of 4000 cGy in 15 fractions seems to be a kinder treatment in glioblastoma patients with a poor performance status.