Linac radiosurgery for benign meningiomas.

Purpose: To review outcomes for patients treated with linac radiosurgery for benign meningiomas.

Methods And Materials: Between January 1989 and July 1997, 70 patients with 76 meningiomas were treated with LINAC-based radiosurgery. In 38 patients, radiosurgery was the initial treatment. In 32 patients, radiosurgery followed surgery or conventional radiotherapy. The average treatment volume was 10.0 cm3 (range, 0.6 to 28.6 cm3). The mean peripheral dose was 12.7 Gy (range, 10 to 20 Gy). The mean clinical follow-up period was 23 months. No patient was lost to follow-up.

Results: No lesions enlarged during the follow-up period; of 48 lesions in patients who had follow-up for at least one year and hence had follow-up imaging, 27 tumors remained unchanged and 21 tumors were reduced in size. Two patients experienced transient radiation-induced neurological deficits. One was treated with surgical excision of the tumor; the other responded to prolonged steroid therapy. Both patients, treated early in our experience, received doses higher than we would currently recommend.

Conclusions: Early results suggest that stereotactic radiosurgery is an effective treatment for meningiomas. Long-term follow-up will be necessary to fully evaluate its efficacy.