Surgery versus radiosurgery for facial nerve schwannoma: a systematic review and meta-analysis of facial nerve function, postoperative complications, and progression

Abstract

OBJECTIVEIntracranial facial nerve schwannomas (FNS) requiring treatment are frequently recommended for surgery or stereotactic radiosurgery (SRS). The objective of this study was to compare facial nerve function outcomes between these two interventions for FNS via a systematic review and meta-analysis.METHODSA search of the Ovid EMBASE, PubMed, SCOPUS, and Cochrane databases from inception to July 2019 was conducted following PRISMA guidelines. Articles were screened against prespecified criteria. Facial nerve outcomes were classified as improved, stabilized, or worsened by last follow-up. Incidence was pooled by random-effects meta-analysis of proportions.RESULTSThirty-three articles with a pooled cohort of 519 patients with FNS satisfied all criteria. Twenty-five articles described operative outcomes in 407 (78%) patients; 10 articles reported SRS outcomes in 112 (22%). In the surgical cohort, facial nerve function improved in 23% (95% CI 15%–32%), stabilized in 41% (95% CI 32%–50%), and worsened in 30% (95% CI 21%–40%). In the SRS cohort, facial nerve function was improved in 20% (95% CI 9%–34%), stable in 66% (95% CI 54%–78%), and worsened in 9% (95% CI 3%–16%). Compared with SRS, microsurgery was associated with a significantly lower incidence of stable facial nerve function (p < 0.01) and a significantly higher incidence of worsened facial nerve function (p < 0.01). Tumor progression and complication rates were comparable. Outcome certainty assessments were very low to moderate for all parameters.CONCLUSIONSUnfavorable facial nerve function outcomes are associated with surgical treatment of intracranial FNS, whereas stable facial nerve function outcomes are associated with SRS. Therefore, SRS should be recommended to patients with FNS who require treatment, and surgery should be reserved for patients with another indication, such as decompression of the brainstem. Further study is required to definitively optimize and validate management strategies for these rare skull base tumors.

Tumor Control Following Stereotactic Radiosurgery in Patients with Vestibular Schwannomas – A Retrospective Cohort Study

“…Our cohort of patients receiving surgical salvage therapy was small and therefore no variable examined was significant in predicting poor outcomes (CSF leak, worsening of facial nerve grade, and completeness of resection). Salvage surgical treatment after SRS in our cohort was notable for higher rates of postoperative complications, for example, 17% with postoperative CSF leak requiring return to the operating room and facial nerve function worse than preoperative function in 65%, compared to primary surgery reported in the literature (64–66). The strategy toward subtotal resection following SRS noncontrol is generally considered a good strategy for facial nerve outcomes, but tumors that continue to grow after SRS are likely more biologically aggressive and are likely at higher risk for continued growth after subtotal resection (67).…”

Safety and Efficacy of Hypofractionated Stereotactic Radiosurgery in Facial Nerve Schwannoma

“…Preoperative facial nerve function is also an important determinant in decision-making in FNS, hence surgeons recommend observation to patients with minimal degradation in facial function; SRS for moderate reduction in facial function; and surgery with or without grafting for poor facial nerve function (HB IV or worse) or for signi cant mass effect [2,12,13]. Studies have suggested that with a treatment goal of preventing the tumor growth while preserving function of facial nerve in FNS, surgery poses a higher risk of facial palsy compared to SRS for facial nerve function [14].…”

Facial nerve schwannoma and other benign neoplastic facial nerve lesions

“…Several studies have reported the efficacy and safety of radiotherapy [13,14]. A previous study reported that the treatment-induced exacerbation of facial nerve paralysis significantly increased with surgery, whereas there was no significant difference in local control rates between surgery and radiotherapy for intracranial facial nerve schwannomas [15]. Regarding local tumor control rate, preservation of facial nerves, and hearing ability, hypofractionated stereotactic radiosurgery is reported to be more beneficial in radiosurgery [16 ▪▪ ].…”