Differential Impact of Treatment Sequencing on Long-Term Facial Nerve Outcomes in Recurrent or Progressive Vestibular Schwannoma: Systematic Review

Introduction: Sporadic vestibular schwannoma (VS) is a common, benign, skull base neoplasm, with multiple highly effective front-line treatments, including microsurgical resection and stereotactic radiosurgery (SRS). Although primary treatment failure is uncommon, many VS will require multiple interventions, and the differential risks of microsurgery and SRS sequencing remains incompletely understood.

Objective: To assess the impact of differential sequencing between microsurgery and SRS for recurrent/progressive VS via systematic review.

Methods: Systematic review of EMBASE, PubMed, and SCOPUS, comparing microsurgery followed by SRS for VS recurrence/progression, versus SRS followed by microsurgery. Favorable facial nerve outcome (HB = 1–2) at last follow-up was the primary endpoint. Random-effect model meta-analysis and meta-regression analysis of outcomes were performed.

Results: A total of 2,533 citations were screened; 10 were included. Four studies documented 378 VS patients treated with microsurgery followed by SRS. Following microsurgery, 188 (49.7%) had favorable facial nerve function. After primary treatment failure and secondary SRS, among 491 patients with accessible data, 249 (50.7%) had favorable facial nerve function. Five studies documented 61 VS treated with SRS then microsurgery. Following SRS, 57 (93.4%) had favorable facial nerve function. 59 patients with primary treatment failure and secondary microsurgery, of which 45 (76.3%) had favorable facial nerve function. Meta-analysis revealed that the proportion of patients experiencing favorable facial nerve function of the SRS then microsurgery cohort (0.87, 95% CI [0.71, 0.95]) was greater than the proportion in the microsurgery then SRS cohort (0.49, 95% CI [0.42, 0.55]; p = 0.003) in patients following the primary intervention before salvage treatment. Additionally, the proportion of patients experiencing favorable facial nerve function of the SRS then microsurgery cohort (0.51, 95% CI [0.46, 0.55]) was lesser than the proportion in the microsurgery then SRS cohort (0.76, 95% CI [0.62, 0.85]; p = 0.001) in patients after salvage treatment ([Figs. 1] and [2]).

Conclusion: Among patients requiring multiple interventions for recurrent/progressive VS, favorable long-term facial nerve outcomes appear to be associated with sequencing SRS as the index intervention. Further study is required to better characterize these findings with respect to key parameters informing treatment decision making, including tumor size, patient age, comorbidities, and individual preferences.

Fig. 1 Favorable House-Brackmann (1/2) meta-analysis and meta-regression prior to salvage therapy.

Fig. 2 Favorable House-Brackmann (1/2) meta-analysis and meta-regression following salvage therapy.

Publication History

Article published online:
01 February 2023