Management of petroclival meningiomas by stereotactic radiosurgery

To evaluate the role of stereotactic radiosurgery in the management of petroclival meningiomas, we retrospectively reviewed our experience with 62 patients managed at the University of Pittsburgh during an 8-year period.

All patients had cranial base meningiomas involving the region between the petrous apex and the upper two-thirds 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 external beam radiation therapy. Using the gamma knife, conformal multiple isocenter radiosurgery was performed with tumor margin doses of 11 to 20 Gy.

During the median follow-up period of 37 months, neurological 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 these tumors to critical neural and vascular structures, complications resulting 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.

Although an even longer follow-up period is desirable, we conclude that stereotactic radiosurgery provides a safe and effective management strategy for petroclival meningiomas, both as a primary procedure and as an adjunct to incomplete resection.