ACTR-03. FINAL RESULTS OF A PHASE II STUDY OF HYPOFRACTIONATED RADIOTHERAPY WITH CONCURRENT AND ADJUVANT TEMOZOLOMIDE IN PATIENTS OVER 70 YEARS OLD WITH NEWLY DIAGNOSED GLIOBLASTOMA

Abstract

Abstract BACKGROUND We sought to determine the efficacy and tolerability of hypofractionated radiotherapy (HFRT), 34Gy given over two weeks with concurrent and adjuvant temozolomide, in patients over 70 years old with newly diagnosed GBM. METHODS Patients ≥ 70 years of age with newly diagnosed GBM received HFRT to a dose of 34 Gy in 10 fractions over 2 weeks, delivered with concurrent and adjuvant TMZ. Quality of life (QOL) data using the validated functional assessment of cancer therapy-brain (FACT-BR) questionnaire was collected. Kaplan-Meier methods and log-rank tests were used for survival analyses. A random intercepts growth model with baseline and linear effect in time terms was used to assess QOL with relation to protocol treatment. RESULTS Eleven patients were enrolled from 12/1/2015 to 2/5/2018. Median age and KPS of the cohort was 74 years (range 70 -81) and 80 (range 60–100). Eight patients have died. Median follow-up of the cohort was 13.8 months (range 3 – 26 months). The median progression free survival (PFS) was 6.0 months (CI 4.7 months -not achieved (NA) and the median overall survival (OS) was 24.5 months (CI 10.2 months –NA). MGMT methylation status was significantly associated with both PFS (p =0.02) and OS (p =0.02). All patients completed HFRT with no patients developing ≥ grade 3 adverse treatment events. QOL did not significantly worsen over time with therapy (p =0.75). CONCLUSIONS This completed phase II trial suggest a HFRT schedule of 34Gy delivered over 2 weeks with concomitant and adjuvant TMZ is well tolerated in elderly GBM patients without compromising clinical outcomes. This result compares favorably to the longer HFRT regimen of 40Gy over 3 weeks. ClinicalTrials.gov identifier: NCT01985087