Hypofractionated whole-brain radiotherapy for multiple brain metastases from transitional cell carcinoma of the bladder

Purpose: Brain metastases in bladder cancer patients are extremely rare. Most patients with multiple lesions receive longer-course whole-brain radiotherapy (WBRT) with 10 × 3 Gy/2 weeks or 20 × 2 Gy/4 weeks. Because its radiosensitivity is relatively low, metastases from bladder cancer may be treated better with hypofractionated radiotherapy. This study compared short-course hypofractionated WBRT (5 × 4 Gy/1 week) to longer-course WBRT. Methods and Materials: Data for 33 patients receiving WBRT alone for multiple brain metastases from transitional cell bladder carcinoma were retrospectively analyzed. Short-course WBRT with 5 × 4 Gy (n = 12 patients) was compared to longer-course WBRT with 10 × 3 Gy/20 × 2 Gy (n = 21 patients) for overall survival (OS) and local (intracerebral) control (LC). Five additional potential prognostic factors were investigated: age, gender, Karnofsky performance score (KPS), number of brain metastases, and extracranial metastases. The Bonferroni correction for multiple tests was used to adjust the p values derived from the multivariate analysis. p values of <0.025 were considered significant. Results: At 6 months, OS was 42% after 5 × 4 Gy and 24% after 10 × 3/20 × 2 Gy (p = 0.31). On univariate analysis, improved OS was associated with less than four brain metastases (p = 0.021) and almost associated with a lack of extracranial metastases (p = 0.057). On multivariate analysis, both factors were not significant. At 6 months, LC was 83% after 5 × 4 Gy and 27% after 10 × 3/20 × 2 Gy (p = 0.035). Improved LC was almost associated with a KPS of ≥70 (p = 0.051). On multivariate analysis, WBRT regimen was almost significant (p = 0.036). KPS showed a trend (p = 0.07). Conclusions: Short-course WBRT with 5 × 4 Gy should be seriously considered for most patients with multiple brain metastases from bladder cancer, as it resulted in improved LC.