P17.04 Gamma knife surgery for Cavernous sinus cavernous hemangioma - comparative results to surgery and radiation therapy

Abstract

Objectives: Cavernous hemangiomas occur very rarely in the cavernous sinus. These lesions share the same histologic features as intracerebral lesions, but their clinical picture is quite different. The objectives of this study are to evaluate the efficacy of Gamma Knife Surgery (GKS) on cavernous sinus cavernous hemangiomas (CSCHs) and to compare the results of GKS to those of surgical treatment and fractionated radiation therapy (FRT). Methods: Before 2000, we operated 7 cases of CSCHs. We have performed GKS for 26 cases and FRT for 4 cases since 2000. Among 26 cases that were treated by GKS, two patients were performed other treatment before GKS (surgery and FRT). Thirteen patients were diagnosed incidentally during the work up of other reason such as headache or head trauma. Most common symptom was cranial nerve palsy (ptosis, diplopia and facial sense change) in 12 cases. Results: Of 7 surgically treated cases, 4 patients had already had extraocular muscle palsy preoperatively. Gross total resection (GTR) was achieved using extradural approach in all 7 cases and there has been no tumor recurrence during follow up. However, 2 new trigeminal nerve deficits developed after operation. FRT was performed for 4 cases, usually large ones. All 4 tumors were well controlled, however, symptomatic radiation necrosis was developed at brainstem in 1 case. Twenty-six patients were treated by GKS. The mean tumor volume was 9.7 cm3 (range 0.5-31.6). The prescription dose to the tumor margin varied from 13 to 15 Gy by the proximity to the optic pathway. The mean follow up period was 46.1 months (range 11.1-131.1). Eleven patients showed marked clinical improvement within 3 months. All the cases showed significant shrinkage of the tumors was noted within 6 months and 11 patients had complete remission at the last follow up (34%). Mean residual volume comparing to pre-GKS initial volume was 20.8% (range 0-70%). There was no complication related to GKS during their follow up. Conclusion: Even though surgical resection for CSCHs is curative treatment, it is not always easy and safe. Because of the radiosensitive nature of CSCHs, FRT could be another treatment option in case of large CSCHs, but it has potential radiation-related risk. GKS is an effective and safe treatment modality and could be a treatment of choice for CSCHs.