Radiosurgery of cavernous sinus tumors

Stereotactic radiosurgery was applied to concentrate high dose of photon irradiation to tumors enclosed in the cavernous sinus. We have treated 10 meningiomas, five pituitary tumors, and three metastatic lesions in the past two years. Follow-up time ranges from 3 to 18 months with an average of 10 months. Tumor volume ranged from 0.92 to 53.31 cc with an average 10.79 cc. CT scans and MRIs were used to demonstrate the tumor relationship to cranial nerves and structures of the brain. One to 6 isocenters were used. Collimator size varied from 7 to 28 mm, and the dose to the margin of the tumor ranged from 1400 to 2500 cGy with an average of 1650 cGy. Maximal dose range of 1575 to 5000 cGy. The margin of the tumor was encompassed within the 50 to 95% isodose volume with an average treatment prescribed to the 57% isodose volume. Symptomatic response was seen in 12 patients, and stabilization of symptoms in three patients with progression of symptoms observed in three patients. Radiographic imaging revealed response in eight patients, unchanged in three patients and progression in three patients. This report shows the feasibility of applying linear accelerator radiosurgery to the treatment of cavernous sinus tumors. This form of therapy promises to play an important role in complementing tumor resection.