Stereotactic radiosurgery for intraventricular brain metastases

Object. The authors' institution previously reported a 69% rate of crude local control for surgical management of lateral ventricle metastases at the University of Texas MD Anderson Cancer Center. For comparison, the authors here report their institutional experience with use of stereotactic radiosurgery (SRS) to treat intraventricular metastases. Methods. To identify patients with intraventricular metastases for this retrospective review, the authors queried an institutional SRS database containing the medical records of 1962 patients with 5800 brain metastases who consecutively underwent SRS from June 2009 through October 2013. End points assessed were local control (crude and locoregional), distant failure free survival, progression-free survival, and overall survival. Results. Of the 1962 records examined, those for 25 (1.3%) patients with 30 (0.52%) intraventricular metastases were identified. Median patient age at SRS was 55.8 years. The most common primary malignancy was renal cell carcinoma (n = 13), followed by melanoma (n = 7) and breast adenocarcinoma (n = 5). Median tumor volume was 0.75 cm(3) (range 0.01-5.6 cm(3)). Most lesions were located in the lateral ventricles (n = 25, 83.3%) and were treated to a median dose of 20 Gy (range 14-20 Gy). A total of 12 (48%) patients received whole-brain radiation therapy, most (n = 10) before SRS. With a median follow-up of 11.4 months (range 1.6-39.2 months), the rate of crude local control was 93.3%, and the rates of 6-month and 1-year actuarial locoregional control were 85.2% and 56.2%, respectively. The median overall survival time after SRS was 11.6 months (range 1.3-38.9 months), and the 6-month and 1-year actuarial rates were 87.1% and 46.7%, respectively. Disease dissemination developed in 7 (28%) patients as a second intraventricular metastatic lesion (n = 3, 12%), leptomeningeal disease (n = 3, 12%), or both (n = 1, 4%). Radiographic changes developed in 5 (20%) patients and included necrosis (n = 2,8%) and hemorrhage (n = 3, 12%). A primary diagnosis of renal cell carcinoma was associated with an improved rate of distant failure free survival (p = 0.05) and progression-free survival (p = 0.08). Conclusions. SRS provides excellent local control for intraventricular metastases, with acceptable treatment-related toxicity, thereby supporting nonsurgical treatment for these lesions. The propensity for intraventricular dissemination among intraventricular metastases seems to be histologically dependent.