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

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.

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.

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.

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.