Radiotherapy of Glioblastoma multiforme. Feasibility of increased fraction size and shortened overall treatment

Purpose: With regard to the poor prognosis of patients with glioblastoma multiforme, the aspect of life quality with a minimal treatment time becomes essential. The purpose of the present study is to evaluate whether the results of a radiotherapy schedule using increased single fractions applied over a shortened treatment time is feasible without compromising treatment efficiency or providing more side effects than a conventionally fractionationed treatment. Patients and methods: A total of 38 patients (f=21, m=17, mean age 58 years) with histologically proven glioblastoma multiforme were irradiated after (partial) resection (n=29) or stereotactic surgery (n=9) with single doses of 3.5 Gy (ICRU) 5 fractions a week up to a total dose of 42 Gy following individual treatment planning. Results: Median survival was 45.7 weeks, survival rate after 6 months was 80.9% and decreased to 34.2% after 12 months. Radiotherapy was tolerated without any important acute toxicity or any late side effects during the follow-up period. Conclusions: The increase of the dose per fraction using a fraction size of 3.5 Gy enhanced neither acute nor late toxicity. The survival rate compared well to those described in the literature. Thus the shortened treatment schedule seems as efficient as conventional radiotherapy. Moreover, it seems preferable with regard to quality of life. (orig.)