Reduction of Overall Treatment Time in Patients Irradiated for More Than Three Brain Metastases

Purpose: Patients with multiple brain metastases usually receive whole brain radiotherapy (WBRT). A dose of 30 Gy in 10 fractions (10 × 3 Gy) in 2 weeks is the standard treatment in many centers. Regarding the poor survival of these patients, a shorter RT regimen would be preferable if it provides a similar outcome as that with 10 × 3 Gy. This study compared 20 Gy in five fractions (5 × 4 Gy) within 5 days to 10 × 3 Gy. Methods and Materials: Data from 442 patients treated with WBRT for multiple brain metastases were retrospectively analyzed. Survival and local control within the brain of 232 patients treated with 5 × 4 Gy were compared with the survival and local control within the brain of 210 patients treated with 10 × 3 Gy. Seven additional potential prognostic factors were investigated: age, gender, Karnofsky performance score, tumor type, interval from tumor diagnosis to RT, extracranial metastases, and recursive partitioning analysis class. Results: On univariate analysis, the WBRT program was not associated with survival (p = 0.29) or local control (p = 0.07). On multivariate analyses, improved survival was associated with a lower recursive partitioning analysis class (p < 0.001), age ≤60 years (p = 0.001), Karnofsky performance score ≥70 (p = 0.015), and the absence of extracranial metastases (p = 0.005). Improved local control was associated with a lower recursive partitioning analysis class (p < 0.001), Karnofsky performance score ≥70 (p < 0.001), and breast cancer (p = 0.043). Grade 3 acute toxicity rates were not significantly different between 5 × 4 Gy and 10 × 3 Gy. Conclusions: Shorter course WBRT with 5 × 4 Gy was associated with similar survival and local control as "standard" WBRT with 10 × 3 Gy in patients with more than three brain metastases. The 5 × 4-Gy regimen appears preferable for most of these patients, because it is less time consuming and more convenient for patients than the 10 × 3-Gy regimen.