Temporal Volume Change of Cavernous Sinus Cavernous Hemangiomas after Gamma Knife Surgery.

Cavernous hemangiomas occur very rarely in the cavernous sinus. This study aimed to evaluate the efficacy of Gamma Knife surgery (GKS) on cavernous sinus cavernous hemangioma (CSCH) and to analyze the temporal volume change. We retrospectively reviewed the clinical data of 26 CSCH patients who were treated with GKS between 2001 and 2017. Before GKS, 11 patients (42.3%) had cranial neuropathies and 5 patients (19.2%) complained of headache, whereas 10 patients (38.5%) were initially asymptomatic. The mean pre-GKS mass volume was 9.3 mL (range, 0.5-31.6 mL), and the margin dose ranged from 13 to 15 Gy according to the mass volume and the proximity to the optic pathway. All cranial neuropathy patients and half of headache patients showed clinical improvement. All 26 patients achieved mass control; remarkable responses (less than 1/3 of the initial mass volume) were shown in 19 patients (73.1%) and moderate responses (more than 1/3 and less than 2/3) in 7 patients (26.9%). The mean final mass volume after GKS was 1.8 mL (range, 0-12.6 mL). The mean mass volume at 6 months after GKS was 45% (range, 5-80%) compared to the mass volume before GKS and 21% (range, 0-70%) at 12 months. The higher radiation dose tended to induce more rapid and greater volume reduction. No treatment-related complication was observed during the follow-up period. GKS could be an effective and safe therapeutic strategy for CSCH. GKS induced very rapid volume reduction compared to other benign brain tumors.