Identification of Patients With Glioblastoma Who May Benefit from Hypofractionated Radiotherapy

Background/Aim: Standard radiotherapy (RT) for glioblastoma lasts 6 weeks. We aimed to identify patients who would benefit from a hypofractionated approach. Patients and Methods: In 167 patients receiving standard fractionation, 10 factors were analyzed for local control (LC) and overall survival (OS). A survival score was developed and compared to a previous instrument. Results: On multivariate analysis, better LC was significantly associated with the presence of only one lesion and O6- methylguanine-DNA methyltransferase (MGMT) promoter methylation. Better OS was associated with one lesion, better performance status, MGMT promoter methylation, and receipt of chemotherapy. Lesion diameter <= 40 mm and upfront resection were associated with improved OS on univariate analyses. Based on assigning scores to these six factors, three groups, with 32-35, 36-44 and 45-48 points, were designed with 12-month OS-rates of 0%, 56%, and 92%, respectively. Accuracy in predicting death within 12 months and survival >= 12 months was 100% and 92%, respectively, versus 67% and 83% with the previous scoring system. Conclusion: A new survival score with higher accuracy was developed for patients with glioblastoma. Our model can be utilized to individualize RT dose-fractionation recommendations for glioblastoma.