Once-Daily and Twice-Daily Radiotherapy without Chemotherapy in the Treatment of Malignant Glioma

Abstract

Aims and Background: To review if hyperfractionated radiotherapy provides better tumor control over standard radiotherapy for malignant glioma without chemotherapy.Methods: The records of 48 patients with glioblastoma multiforme or anaplastic astrocytoma treated with hyperfractionated/standard radiotherapy were reviewed for survival and prognostic factors analyses. The radiation schedule consisted of standard fractionation (1.8~2 Gy/day) or hyperfractionated fractionation (1.2~1.5 Gy twice/day with at least 6 hours interval), depending on the preference of different physicians. None of them received chemotherapy. Eight patients underwent biopsy only, and 28 patients underwent subtotal resection. The rest 12 patients had gross tumor resection. Survival rates were estimated using the method of Kaplan and Meier. In univariate analyses of survival time, the different variables were compared using the log rank test. Within the framework of Cox regression models, multivariate analysis was performed to differentiate the relationships between variables and their relevance to the survival.Results: No patient was lost to follow-up. Median survival was 13 months (range, 1-158 months). Two patients had complete response after radiotherapy. Twenty-two had partial response. The other 24 had stable disease or progression. The hyperfractionated radiotherapy group didn't show any benefit on survival (13 vs. 16.733 months, p=0.439). Age older than 50 years showed worse prognosis in both univariate and multivariate analyses. Tumor involvement more than one lobe, grossly total resection not achieved, and biologically equivalent dose (assuming α/β ratio=10) (BED10) less than 72 GyE had trends associating with worse prognosis, which were not statistically significant.Conclusion: In our study, patients didn't benefit from hyperfractionated radiotherapy. Due to small patient number, further investigation is warranted to evaluate the benefit and toxicity of hyperfractionated radiotherapy.