Fractionations in radiotherapy of brain metastases.

ABSTRACT

AIMS AND BACKGROUND: The aim of this study was to evaluate different fractionations for radiotherapy of brain metastases. METHODS: One hundred and twenty-five patients treated with whole brain cobalt therapy (WBRT) were examined to evaluate the effect on survival and quality of life of three different dose fractionations (2 Gy x 25, 3 Gy x 10 and 4 Gy x 5). Fractionation was evaluated in relation to mean survival, single or multiple lesions, presence of extracranial metastases, primary tumor control and neurological status before and after treatment. Kaplan-Meier analysis of survival and univariate and multivariate analysis of these factors were performed. Twenty-six (21%) patients were treated with 2 Gy x 25, 48 patients (38%) with 3 Gy x 10 and 42 patients (33%) with 4 Gy x 5. The other 9 patients were treated with unusual fractionations. RESULTS: In 66% of patients an improvement in neurological status after radiotherapy was recorded. Patients with controlled primary tumors had a better mean survival, 8.6 months, if they had no extracranial metastases. The six-month survival was 21% in the 4 Gy x 5 group, 36% in the 3 Gy x 10 group, and 21% in the 2 Gy x 25 group; the results for one-year actuarial survival were highly similar in the three fractionation groups (5%, 11% and 6%, respectively). CONCLUSIONS: The use of 5 x 4 Gy fractionation may be appropriate in lung cancer patients, where no significant difference in 6- and 12-month survival was observed with respect to the other fractionation groups despite the most unfavorable prognosis of these patients and the lower biological effectiveness of this fractionation with respect to the other schedules.