Intracranial hemangiopericytoma: clinical experience and treatment considerations in a modern series of 40 adult patients.

INTRODUCTION: Intracranial hemangiopericytoma (HPC) is a malignant meningothelial tumor. Because of its rarity, few guidelines exist for optimal management.
METHODS: University of California at San Francisco patients managed for intracranial HPC were compiled into a single database based on a retrospective review of patient records. Univariate and multivariate regression was performed to determine factors that independently predicted treatment outcomes.
RESULTS: A total of 40 patients with intracranial HPC were treated from 1989 to 2010. Treatment and follow-up information was available for analysis on 35 patients. The median survival for all patients was 16.2 years after date of diagnosis, with 1-year, 5-year, and 10-year survival rates of 100%, 92%, and 68%, respectively. Nineteen patients (54%) had HPC recurrence. The median time until recurrence was 5 years, with 1-year, 5-year, and 10-year progression-free survival rates of 96%, 49%, and 28%, respectively. Seven patients (20%) developed extracranial metastasis. Tumor characteristics associated with earlier recurrence included size ≥6 cm (log-rank, P < .05) and nonskull base location (log-rank, P < .05). Strategies combining adjuvant radiation with tumor resection appeared to hinder tumor progression, but had no effect on overall survival or the development of metastasis. Greater extent of resection was associated with increased overall survival (log-rank, P < .05).
CONCLUSIONS: Adjuvant radiation may show promise in preventing tumor progression, but recurrence remains a common treatment outcome regardless of initial strategy. When safe and feasible, gross total resection should be pursued as an initial surgical strategy to maximize overall survival. The propensity of these tumors to metastasize makes detailed staging imaging necessary.