RADT-44. COMPARATIVE ANALYSIS OF HYPOFRACTIONATED SHORT-COURSE VERSUS STANDARD RADIATION THERAPY IN ELDERLY PATIENTS WITH GLIOBLASTOMA: ANALYSIS OF NATIONWIDE DATABASE

Abstract PURPOSE Hypofractionated short-course radiation therapy (SCRT) is an alternative treatment option for elderly or frail patients with newly diagnosed glioblastoma (GBM) post-surgery. This study compares survival outcomes and treatment costs between patients receiving SCRT and those undergoing standard long-course radiation therapy (LCRT). METHODS This retrospective study utilized health insurance claims and national cancer registry data from Korea to compare overall survival (OS) and treatment costs between patients receiving SCRT and LCRT across all ages and sub-group analysis within the subgroup of cases aged 65 and older from 2016 onwards, a period when intensity-modulated radiotherapy (IMRT) was widely adopted. RESULTS A total of 1,598 patients were included. Median OS since the first day of radiation therapy was 10.4 months (95% CI [9.6; 12.8]) for SCRT (n = 197) versus 16.2 months (95% CI [15.5; 16.9]) for LCRT (n = 1401), respectively. Subgroup analysis using stabilized inverse probability of treatment weighting (S-IPTW) showed indicating non-inferiority in elderly patients in median OS for elderly patients (≥ 65) with 10.6 months (95% CI [8.9; 14.0]) for SCRT (n = 147) versus 13.2 months (95% CI [8.9; 14.0]) for LCRT (n = 541). The median treatment cost of SCRT is about 6,000 USD lower, 25% less than LCRT. Compliance with the standard TMZ regimen post-radiation improved OS across all age groups. CONCLUSION Considering comparable OS and shorter treatment duration, SCRT offers a viable, cost-effective option for elderly GBM patients. Adhering to standard TMZ also contributes to OS improvement. Further research reflecting key prognostic factors is essential to refining the role of SCRT.