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

Abstract

Background: The debate continues with a limited number of publications describing outcomes in patients with vestibular schwannoma (VS) treated with planned subtotal resection (STR) plus stereotactic radiosurgery (SRS). Here we present our experience. Methods: This is a retrospective review of 22 patients with VS Koos grade III and IV who were treated with STR followed by SRS. Tumor volumes, facial nerve function, hearing preservation, and the presence of trigeminal neuropathy were noted. Spearman's rank test was used to correlate facial nerve grade with postoperative tumor residual tumor volume. Results: Tumor control was achieved in all patients with a mean follow-up of 28 months. No patient required other treatment beyond the original surgery and adjuvant SRS during this period. After a mean postoperative period of 28 months, 19/22 patients had excellent (House-Brackmann I or II) facial nerve function grading. Improved facial nerve function was positively correlated with larger residual tumor volume (r_s = 0.63). Kaplan-Meier curve showed around 80% probability for regaining facial nerve function after initial deterioration. Four patients reported postoperative facial numbness at the side of surgery, with 3 cases showing improvement within a month. Temporary postoperative caudal cranial nerve dysfunction was observed in 2 patients. Conclusion: Hybrid strategy of STR and adjuvant SRS provides patients with large VS excellent tumor control and a good clinical outcome.

Preserving normal facial nerve function and improving hearing outcome in large vestibular schwannomas with a combined approach: planned subtotal resection followed by gamma knife radiosurgery

“…Tumor growth control was achieved in 93.8%. Recently, Radwan et al [53] have presented their results in a series of 22 patients treated with planned subtotal resection. Seventeen of them had radiosurgery and 5 wanted to undergo a “wait-and-scan” strategy for the remnant.…”

“…The mean time between surgery and radiosurgery was 9.5 months. In this series, the radiosurgery management was heterogeneous, with 9 cases undergoing GKRS and 7 hypofractionated regimens [53]. …”

Intentional Subtotal Resection of Vestibular Schwannoma: A Reexamination

“…Two of the largest studies of intentional STARS report over 90% tumor control, yet have less than an average of 3 years followup data. 18,19 A recent meta-analysis of intentional STARS demonstrated 94% tumor control at a median of 48 months and excellent facial nerve outcomes in 96%. 9 However, according to one of the largest purely surgical series with decades of available data, failure of tumor control is rare in the first 5 postoperative years regardless, though extent of resection remains the greatest protective factor against recurrence.…”

Awake craniotomy for vestibular schwannoma

“…One may assume that the smaller the remnant, the less risk of recurrence. The strategy of doing near-total resection, leaving a very thin tumour remnant on the facial nerve is gaining increasing support, as this may lead to better facial nerve outcomes; the remnant grows slowly or not at all, and radiosurgery may stop further growth [2,8,10]. Near-total resection may, however, increase the risk of damage to the cochlear nerve.…”

“…Subtotal resection may lead to tumour recurrence and hearing loss later on, similar to what is reported for radiosurgery. One recently published strategy is to do a subtotal resection followed by radiosurgery [4,8]. It remains to be seen if any of the two strategies will gain widespread use.…”