Radiation therapy for incompletely resected meningiomas.

Twelve patients with incompletely resected meningiomas were treated with postoperative radiation therapy. Nine of these patients had previously undergone incomplete surgical resection, and three had suffered one or more postoperative recurrences. The median dose of irradiation was 5490 rads in 6 weeks (range 4800 to 6080 rads). All patients were followed with serial neurological examinations and computerized tomography (CT) scans. Median follow-up period was 54 1/2 months (range 20 to 120 months); 10 of the 12 patients were followed for longer than 42 months posttreatment. Nine patients had no clinical evidence of recurrent disease after radiation therapy, and CT scans confirmed lack of progression or a gradual decrease in tumor size. Three patients had tumor recurrences; two of these lesions appeared at 70 and 112 months after irradiation as extracranial extensions beyond the margin of the irradiation field, and one has exhibited recurrence within the field at 48 months. Three patients who were treated after prior recurrences have demonstrated prolonged progression-free intervals in comparison to the intervals between recurrences prior to irradiation. No significant complications attributable to treatment have been found in any of the patients. These results are discussed in relation to previous reports of the incidence of meningioma recurrence after incomplete resection.