Postoperative hypofractionated radiotherapy in glioblastoma multiforme

To evaluate the safety and efficacy of hypofractionated radiotherapy (HRT) in glioblastoma multiforme (GM) patients in terms of overall and progression-free survival.

Adult patients with GM were prospectively treated with HRT after total, subtotal or partial tumor excision. HRT was applied 3 days a week with a tumor dose of 3.33 Gy per fraction. At the first phase of treatment 12 fractions and at the second phase 3 fractions with smaller fields were delivered. The total dose was 50 Gy/15 fractions/5 weeks. The results were compared with a historical control group of GM patients treated with conventional RT.

20 patients with GM were treated between 1997-2000 at our department. The tumor was multifocal in one (5%) case. The types of operations used were total tumor excision 10(50%) cases, subtotal excision 5 (25%) cases and partial excision 5 (25%) cases. For the historical control group the corresponding operations were 19 (56%), 6 (18%) and 9 (26%). In the study group one-year survival was 50% and median survival 12 months. Mean overall survival was 13.5 (11.3 months for the historical control group, p=0.16) and progression-free survival 6.8 months (5.6 for the historical control group, p=0.36). Treatment was well tolerated. Acute toxicity was minimal and only one HRT patient had late toxicity (brain necrosis).

The mean overall survival with HRT was better but statistically non significant compared with the historical control group. Our study supports that HRT can be used instead of conventional and hyperfractionated radiotherapy and studies of HRT with higher doses may be meaningful.