Gamma knife stereotactic radiosurgery for intracranial hemangiopericytoma.

BACKGROUND

Intracranial hemangiopericytoma (HPC) is a rare tumors that comprises under 1% of all primary brain tumors. This tumor is notable for its aggressive clinical behavior, such as a high rate of recurrence after surgical resection and proclivity for extracanial metastases. For the management of recurrent intracranial tumors, we applied Gamma Knife radiosurgery (GKRS) in cases in which the tumors were well-circumscribed and measured less than 3 centimeters in diameter. In this study, we evaluated the efficacy and role of GKRS in controlling recurrent HPC.Materials and Methods: Between April 2004 and July 2010, we treated seven patients with intracranial HPC using GKRS. All patients underwent surgical resection prior to GKRS. The mean age of the patients at the first GKRS was 43.4 (range, 29 to 68) years. At the first GKRS, six patients of seven patients had one tumor, and the remaining patient had four tumors. Therefore, a total of 10 tumors were detected at the first GKRS, all of which were treated. The median follow-up time was 52.1 months (range, 13 to 71 months). During follow-up, three of the seven patients underwent a total of 22 repeat GKRS procedures for newly developed tumors or 4 lesions with regrowth. Ultimately, a total of 32 GKRS procedures were performed in the seven patients. The mean radiosurgery target volume was 4.1 ml (range, 0.3-23.9ml), and the mean marginal dose was 16.5 Gy (range, 10-20).

RESULTS

Five patients were alive at the end of the follow-up visit, without any serious neurological deficits. One patient presented with extracranial metastasis and died from cerebrospinal dissemination of the tumor 71 months after the first GKRS. Another patient died from colon cancer during follow-up. The 1-, 3-, and 5-year local tumor control rates were 100%, 92% and 69.7%, respectively.

CONCLUSIONS

GKRS is an effective management option for patients with recurrent hemangiopericytoma.