MANAGEMENT OF PETROCLIVAL MENINGIOMAS BY STEREOTAXIC RADIOSURGERY

OBJECTIVE: To evaluate the role of stereotactic radiosurgery in the ma nagement of petroclival meningiomas, we retrospectively reviewed our e xperience with 62 patients managed at the University of Pittsburgh dur ing an 8-year period. METHODS: All patients had cranial base meningiom as involving the region between the petrous apex and the upper two-thi rds of the clivus. Some tumors extended into the cavernous sinus. Each of 39 patients (63%) had previously undergone one or more attempts at surgical resection. Seven patients (11%) had received fractionated ex ternal beam radiation therapy. Using the gamma knife, conformal multip le isocenter radiosurgery was performed with tumor margin doses of 11 to 20 Gy. RESULTS: During the median follow-up period of 37 months, ne urological statuses improved in 13 patients (21%), remained stable in 41 patients (66%), and eventually worsened in 8 patients (13%). Tumor volumes decreased in 14 patients (23%), remained stable in 42 patients (68%), and increased in 5 patients (8%). Despite the proximity of the se tumors to critical neural and vascular structures, complications re sulting from radiosurgery were rare. Five patients (8%) developed new cranial nerve deficits within 24 months of radiosurgery, although none had evidence of tumor progression. These deficits resolved completely in two patients within 6 months of onset. CONCLUSION: Although an eve n longer follow-up period is desirable, we conclude that stereotactic radiosurgery provides a safe and effective management strategy for pet roclival meningiomas, both as a primary procedure and as an adjunct to incomplete resection.