Long-Term Follow-Up of 32 Meningiomas of the Clivus and Foramen Magnum Subjected to Stereotactic Radiosurgery

Introduction: Meningiomas of the clivus and foramen magnum are infrequent and are difficult to treat surgically because of their location, access, and the associated vascular and nerve structures. Such lesions are often candidates for stereotactic radiosurgery (SRS). Objective: A retrospective analysis is made of the results of SRS in 32 patients with menigioma of clivus and foramen magnum, subjected to a median follow-up period of 6 years. Material and Methods: A total of 32 patients, mean age of 55.13 +/- 13.36 years, were studied. 16 patients (50%) had undergone prior surgery 12.2 +/- 12.8 months before SRS. Median tumor volume (TV) 13.195, median dose was 1,400 cGy, prescribed to the 90% median isodose line. In 19 cases (59.37%) coverage of the TV was partial. Results: After a median follow-up of 6 years (2.2-11.3), significant TV reduction was observed (final TV 13.49 +/- 13.37 p < 0.001). Tumor control was achieved in 29 patients (90.6%). The prior symptoms improved in 16 cases (50%), remained without change in 13 (40.6%), and worsened in 3 (9.4%). Conclusions: SRS provides a safe and effective strategy for clivus and foramen magnum meningiomas being a clear alternative of microsurgical removal. With a median of follow-up of 6 years, no cranial nerve palsy was found. A long follow-up is necessary. Copyright (C) 2010 S. Karger AG, Basel