Management of Large Vestibular Schwannomas by Combined Surgical Resection and Gamma Knife Radiosurgery

Abstract

In this report, we evaluated the treatment results of a combination of surgery and radiosurgery for large vestibular schwannomas. The series of 8 patients included in this study underwent surgery followed by radiosurgical treatment between January 2000 and January 2006. The patients included 5 males and 3 females aged 24-78 years (mean age: 53 years). The average maximum diameter of the tumor was 40 (35-45) mm. At the time of radiosurgery, the treatment size became 18 (9-20) mm. The mean peripheral dose administered was 11.8 (range 11-13) Gy, and the mean dose administered in the centre of the tumor was 23.75 (22-26) Gy. The mean follow-up period was 46 months after radiosurgery. Excellent facial nerve function (House-Brackmann grade 1 or 2) was preserved in 7/8 patients (87.5%). In the case of large vestibular schwannomas, the combined management is one option for maintaining cranial nerve function and tumor growth control.

Efficacy of facial nerve–sparing approach in patients with vestibular schwannomas

“…This work confirms previous studies indicating that microsurgical resection followed by GKS for recurrence yields better rates of facial nerve function than total resection alone for tumors of this size. 4,7 Patients received intraoperative electrophysiological monitoring and lower radiation doses (12 Gy to the 50% isodose line), techniques that are shown to have a better prognosis of facial nerve preservation, which may contribute to the efficacy of our facial nervesparing technique. 21,22 Combining surgery for good control of tumor growth with GKS for tumor expansion prevents facial nerve deficits in patients who might otherwise have a significant risk of facial nerve dysfunction.…”

“…4,7 This series corresponds to patients who were dedicated to the combined approach of microsurgery and GKS from the beginning of their treatment. We show that this approach provides excellent facial nerve function (97% good facial nerve function) with a low risk of tumor regrowth (13.2% of patients required retreatment).…”

“…Studies of tumors treated with microsurgery followed by radiosurgery have been encouraging; facial nerve-sparing techniques can retain facial nerve function in 85% of cases. 4,7,17,18 Despite these encouraging results, the risk of regrowth increases with STR, with resulting morbidities as discussed previously. 1 Larger case studies from a single surgeon will provide stronger support for this facial nerve-preservation technique.…”

Outcomes in Patients with Vestibular Schwannoma after Subtotal Resection and Adjuvant Radiosurgery

“…The debate continues over complete versus incomplete removal as the best management strategy for patients with VS. To date, there have only been a few studies involving a limited number of patients in which outcomes of subtotal removal followed by adjuvant radiosurgery in the treatment of large VS have been analyzed [11,12,13,14,15,16,17]. In the present study, we achieved a 100% tumor control rate, with 87% of our patients showing excellent facial nerve function in the follow-up.…”

Gamma Knife Radiosurgery for the Vestibular Schwannomas, Technical Considerations and Hydrocephalus as a Complication

“…In selecting a candidate for radiosurgery, tumour size should be a primary consideration. To prevent complications (in particular, facial nerve palsy), some authors recommend using a partial or subtotal microsurgical removal approach while applying special care to preserve the facial nerve, and this should then be followed by a secondary gamma knife radiosurgery (Fuentes et al, 2008;C. K. Park et al, 2006).…”