Stereotactic Radiosurgery of Colorectal Carcinoma Brain Metastasis: A Multi- Institutional Experience

Purpose: Colorectal cancer is one of the most common cancers with one of the poorest survival rates following brain metastasis. Only a few studies have described outcomes after radiosurgery and predictors of mortality in these patients. We describe a multi-center experience in the treatment of colorectal cancer metastases to the brain using stereotactic radiosurgery. Material and Methods: A retrospective review of 66 patients treated over 1993 to 2009 with at least one follow-up was undertaken. Median time to death and its predictors were calculated using Kaplan Meier survival analysis and Cox proportional hazard model. Results: Overall median survival for patients with colorectal cancer was 4.05 months with a mortality of 58 (84.06%) patients over a mean follow-up of 7.03+12.44 months. Both survival analysis and multivariate analysis revealed KPS>70 as the only significant predictor of survival (median survival KPS >70: 6.91 months versus KPS < 70: 1.74 months, p=0.004; Hazard ratio for KPS>70 was 0.31, p=0.001). When total volume did not exceed 5.4 cc3, the patients with volume distributed over fewer lesions had improved survival. No such association was observed with higher volumes. Conclusions: SRS moderately improves survival of patients with colorectal cancer metastatic to brain. Higher KPS predicts favorable prognosis in these patients. Categories: Radiation Oncology, General Surgery, Neurosurgery