RTHP-32. PHASE II STUDY OF HYPO-FRACTIONATED ACCELERATED RADIOTHERAPY WITH CONCURRENT AND MAINTENANCE TEMOZOLOMIDE IN NEWLY DIAGNOSED GLIOBLASTOMA: COMPLIANCE AND EARLY CLINICAL OUTCOME (HyART)

Abstract

INTRODUCTION: To compare hypo-fractionated (HyRT) with conventional fractionated radiotherapy (CRT) for good prognosis newly diagnosed patients with glioblastoma (GBM). METHODS: HyART, a Phase II trial randomly assigned newly diagnosed GBM patients 1:1 by computer generated randomization chart to HyRT and CRT. Patients of 16 - 65 years, Karnofsky performance score ≥70 and maximal safe surgical resection were randomized. SPSS v16. was used for all statistical analysis. RESULTS: 83 patients randomized, 77 were evaluable. Median age 45 years (Range: 16-65). Male: Female ratio was 2:1. 20(25.9%) patients had seizure at presentation. Median symptom duration was 2 months (1 day-72 months). 49 patients had GTR. Only two patients required hospitalization for features of raised intracranial pressure during radiation and two required long duration steroid after RT in the HyRT arm. Three patients in HyRT arm grade III thrombocytopenia during maintenance phase. At a median follow up of 9 months 31 experienced disease progression. However, none of the patient has a documented radio necrosis as of now. Median PFS was 13.1 months (95% CI: 11.7-14.5 months). Median PFS was significantly better for GTR than STR (14.1 vs 9.6 months; p=0.004). Patients operated at high volume center have better PFS (14.1 vs 9.6 months). Median PFS was better but not significant for IDH mutated patients (16.3 vs 13.1 months). A delay in initiation of RT by more than 6 weeks conferred worse PFS (9.9 vs 14.2 months; p=0.022). There was no difference in PFS for patients treated with HyRT vs CRT. Estimated median OS was 29.6 months (95% CI: 19.1- 40.1 months). CONCLUSION: HyRT appears to be well tolerated with no treatment interruption and equivalent survival compared to CRT.