Stereotactic radiosurgery and hypofractionated stereotactic radiotherapy for management of vestibular schwannomas: initial experience with 17 cases
Nowadays radiation treatment of patients with vestibular schwannomas (VSs) applied either as stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT) represents a real alternative to surgical tumor resection. During 2010-2011, 17 consecutive patients (19-75 years old) with a VS underwent treatment with SRS or SRT in our center. Microsurgery was initially offered in all cases but was declined for various reasons. Five lesions recurred after the initial partial resection. Two other patients with neurofibromatosis type 2 underwent initial surgery for a large tumor on the contralateral side and had the only hearing ear on the side of the remaining neoplasm. Three elderly persons had somatic problems that were too severe for them to undergo craniotomy. Five small tumors without brain stem compression underwent single-fraction SRS (12.0-12.5 Gy at the 80 % isodose line). Other patients, mainly with large neoplasms that caused brain stem compression, were treated with hypofractionated SRT (five or six daily fractions at a dose of 4.5-5.0 Gy each). Treatment was performed with a dedicated linear accelerator (Elekta Axesse). Various stereotactic fixation devices were used: Leksell G frame, noninvasive HeadFIX frame, reinforced thermoplastic masks. No adverse reactions or complications were seen in any case. Within 3 months after treatment three tumors demonstrated shrinkage accompanied by improvement of the neurological functions. Radiation treatment, particularly hypofractionated SRT, can be safely applied even for large VSs that cause brain stem compression and are accompanied by prominent neurological symptoms.