Long-term Follow-up Results of Gamma Knife Radiosurgery for Benign Tumors Involving Cavernous Sinus

ABSTRACT

OBJECTIVE: We describe our long-term experiences of gamma knife radiosurgical treatment on benign tumors involving cavernous sinus, including meningiomas, trigeminal neurinomas and pituitary adenomas. METHODS: From June 1990 to January 2001, forty-two patients with benign cavernous sinus tumors were treated with gamma knife radiosurgery in our institution. Of these, twenty-seven patients(64%) had precedently undergone open surgery and others(36%) were treated only with gamma knife. Tumor type distribution was meningiomas(n=20, 48%), trigeminal neurinomas(n=8, 19%) and pituitary adenomas(n=14, 33%). Mean follow-up period was 42.4 months. Mean tumor volume and mean marginal dose were 6.8cm3(Lange 0.37-39.3cm3 and 17.6Gy(range 11-35Gy) respectively. RESULTS: Tumor control was achieved in thirty-nine patients(93%). Tumor enlarged in two patients(1 meningioma and 1 pituitary adenoma). One patient with neurofibromatosis(type 2) accompanied with trigeminal neurinoma expired due to disease progression. Hormonal relapse was occurred three years after radiosurgery for pituitary adenoma in one patient. There were functional improvement in seven patients, including relief in facial pain(2 patients) and improvements of trigeminal nerve or abducens nerve deficits(5 patients). Three tumors have shown cystic change which have been of indolent course. Complications after radiosurgical treatment were oculomotor and abducens nerve palsies in one patient. CONCLUSION: For benign tumors involving cavernous sinus, gamma knife radiosurgery with its excellent long-term tumor control rates and minimal morbidity could serve as a first treatment modality or combination with open surgery in selected patients.