Fractionated Stereotactic Radiosurgery(FSRS) for Sella and Parasella Tumors Adjacent to Optic Apparatus

ABSTRACT

OBJECTIVE: Compared with other neural structures, optic apparatus are particularly sensitive to radiation. If tumors are adjacent to or in contact with optic apparatus, a number of limitations need to be addressed for planning radiosurgery. To avoid radiation induced optic neuropathy, we treated these lesions with fractionated stereotactic radiosurgery (FSRS). This study is undertaken to assess the efficacy of FSRS for sella and parasella tumors adjacent to or in contact with optic apparatus. METHODS: We treated 19 sellar region tumors located adjacent to or in contact with optic apparatus with fractionated stereotactic radiosurgery using the Novalis system. Seventeen patients who could be followed were included in this study. They consisted of 8 pituitary adenomas, 4 optic gliomas, 3 meningiomas, 2 craniopharyngiomas. The mean tumor volume was 16.1cc(range 1-61.1). When planning FSRS, the prescribed fractionation dose to optic apparatus below 200cGy. Follow up examinations consisted of neurological, neuroradiological, and neuroopthalmological evaluations. RESULTS: Follow-up ranged from 2 to 34 months(mean 15 months). Serial magnetic resonance imaging revealed no increase in volume of tumor in all 17 patients. No patients had radiation induced optic neuropathy. CONCLUSION: Fractionated stereotactic radiosurgery is proper innovative treatment modality for sella or parasella tumors adjacent to or in contact with optic apparatus to avoid radiation induced optic neuropathy. We need further follow-up and clinical experiences.