Intraventricular metastasis: a systematic review of patient demographics, clinical characteristics, and outcomes.

[BACKGROUND] Intraventricular metastases (IVM) are rare occurrences of brain metastases that arise within the ventricles from primary tumors elsewhere in the body. While brain metastases are common, IVM account for only 1-2% of such cases and present unique treatment challenges due to their deep-seated location. This systematic review aims to comprehensively analyze patient demographics, clinical characteristics, treatment approaches, and outcomes for individuals diagnosed with IVM.

[METHODS] A systematic search of online journals was performed to identify and include studies regarding metastases within the brain's ventricles from non-central nervous system (CNS) primary tumors. Data on demographics, clinical features, tumor characteristics, treatment modalities, and survival outcomes were analyzed. A total of 54 studies comprising 141 patients were included.

[RESULTS] The average age was 58 years, with a male predominance (66%). Renal cell carcinoma (RCC) was the most common primary tumor (46%), followed by lung (20%), thyroid (8%), and breast cancer (7%). Most metastases occurred in the lateral ventricles (80%). Treatment included surgery (38%), radiotherapy alone (29%), and combined modalities (18%). The average survival from metastasis diagnosis to death was 1.3 years. No significant survival differences were observed between patients with renal versus non-renal primaries or between isolated IVM and those with additional metastases, though isolated IVM patients showed a longer survival trend.

[CONCLUSIONS] IVM are exceedingly rare, with RCC representing a disproportionate number of cases. Surgical resection remains the predominant treatment, though outcomes remain poor. Future research should focus on early detection and tailored therapeutic approaches to improve prognosis.