Image-guided stereotactic radiotherapy for patients with vestibular schwannoma

Abstract

Local tumor control and functional outcome after linac-based stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) for vestibular schwannoma (VS) were assessed. In all, 250 patients with VS were treated: 190patients with tumors < 2cm diameter underwent SRS and 60patients with tumors >2 to 3.5cm underwent FSRT. Dose prescription for all cases with SRS (n = 190, 76 %) was 13.5Gy. For FSRT, mainly two hypofractionated schedules (n = 60, 24 %) with either 7fractions of 5Gy (total dose: 35Gy; n = 35) or 11fractions of 3.8Gy (total dose: 41.8Gy; n = 16) were used. The primary endpoint was local tumor control. Secondary endpoints were symptomatic control and morbidity. The median follow-up was 33.8months. The 3-year local tumor control was 88.9 %. Local control for SRS and FSRT was 88 and 92 %, respectively. For FSRT with 35 and 41.8Gy, local control was 90 and 100 %, respectively. There were no acute reactions exceeding gradeI. In 61cases (24.4 % of the entire cohort), trigeminal neuralgia was reported prior to treatment. At last follow-up, 16.3 % (10/61) of those patients reported relief of pain. Regarding facial nerve dysfunction, 45patients (18 %) presented with symptoms prior to RT. At the last follow-up, 13.3% (6/45) of those patients reported a relief of dysesthesia. Using SRS to treat small VS results in good local control rates. FSRT for larger lesions also seems effective. Severe treatment-related complications are not frequent. Therefore, image-guided stereotactic radiotherapy is an appropriate alternative to microsurgery for patients with VS.