Long-term efficacy of fractionated radiotherapy for benign meningiomas.

Purpose: To assess long term efficacy of fractionated stereotactic radiotherapy (fSRT) in the treatment of benign intracranial meningiomas.

Materials And Methods: Retrospective study of 222 patients with histologically confirmed (58%) and unverified presumed (42%) grade I intracranial meningioma treated with fSRT in a single institution to doses of 50-55Gy in 30-33 fractions.

Results: At a median follow-up of 43months (range 3-144) the 5 and 10years local control (LC) were 93% and 86%. Patients with tumors involving the optic nerve (42 patients) and patients with cavernous sinus/parasellar region meningiomas (78 patients) had 5 and 10years LC of 100%. The 5 and 10years survival probabilities were 93% and 84%. On multivariate analysis gender and tumor site were independent predictors of LC. Worsening of pre-existing cranial nerve deficit occurred in 8 (3.5%) and onset of new deficit in 1 (0.5%) patient. Two patients with optic nerve sheath meningioma (1%) developed radiation retinopathy. There were no cases of radiation necrosis or second brain tumors.

Conclusion: fSRT achieves excellent medium and long term tumor control with minimal morbidity particularly in patients with benign meningiomas involving the parasellar region and the optic nerves and questions the role of other treatment modalities for tumors at these locations.