We investigated the effectiveness and the benefit of fractionated GKS in skull base meningioma which shows minimal symptom but be adjacent to critical structure.

     We retrospectively searched our institute records for 12 patients underwent fractionated GKS from 2006 to 2008 and evaluated overall survival, tumor control rate, toxicity, and symptomatology. The mean age was 61.2 years (range 37 ~ 81 years). 3 patients were male and 9 patients were female. 10 patients were treated with GKS as a primary treatment and 2 patients underwent previous operations

     Median follow up duration was 16 months (range 12 ~ 26 months). Tumor volumes measured between 4.3 and 53.2 cc (median 11.5 cc). The mean prescription dose at the tumor margin was 5.6 Gy (range 5 ~ 8 Gy) and the mean fraction time was 2.8 times (range 2 ~ 3 times). Overall survival rate for 1 year were 100%.

     Tumor control was achieved in 100% of our series (16.6% tumor regression, 83.4% stable size). Quantitative tumor volume reduction was 21.4% for 1 year. 91.7% of the patients improved their symptoms or were stable. Clinically significant acute toxicity was not seen. In one case, adverse radiation effect was detected (defined as a new post-GKS edema), but silent. There was no complication such as new cranial nerve palsy.

     This is a retrospective study.

     Fractionated GKS represents a safe and effective treatment modality that can be recommended for large skull base meningiomas in critical locations either after incomplete surgery or as primary treatment for patients with no or minimal symptoms.

     Although, it requires long term follow-up to assess the effectiveness of fractionated GKS.