Objectives/hypothesis: To evaluate outcomes of salvage surgery for vestibular schwannoma (VS) that failed primary stereotactic radiosurgery (SRS).
Methods: Case-control study of 37 patients who underwent surgical resection of sporadic VS following prior SRS at two tertiary academic referral centers between 2003 and 2015. A cohort of nonirradiated control subjects, matched according to tumor size, age, and treatment center, were used as comparison.
Results: Thirty-seven patients were included. The median time from radiation to surgical salvage was 36 months (range 9.6-153 months). Following tumor progression after SRS, 18 (49%) patients underwent gross total resection, 10 (27%) underwent near-total resection, and nine (24%) underwent subtotal resection. Postoperative complications following salvage surgery included one (3%) case of stroke, four (11%) cases of cerebrospinal fluid leak, and two (5%) cases of meningitis. Twenty-seven (73%) patients had good postoperative facial nerve outcome (House-Brackmann Score I-II) at long-term follow-up. There were no cases of tumor recurrence or regrowth after a median length of 26 months following microsurgical salvage (range 3-114 months). The rate of satisfactory postoperative facial nerve function was not different between study and control subjects (73% vs. 76%; P = 0.8); however, less-than-complete resection was utilized more frequently among previously radiated patients (P = 0.01).
Conclusion: Microsurgical salvage of VS following primary radiation therapy is challenging. Less-than-complete resection is required in a greater percentage of patients to preserve facial nerve integrity and prevent neurological complications. Long-term follow-up is needed to determine the risk of delayed progression following incomplete tumor removal.
Level of evidence: 3b. Laryngoscope, 126:2580-2586, 2016.
Keywords: Vestibular schwannoma; acoustic neuroma; gamma knife; microsurgery; radiosurgery; recurrence.
© 2016 The American Laryngological, Rhinological and Otological Society, Inc.