Daher, Ghazal S.

AbstractObjectiveTo examine associations with changes in quality‐of‐life (QOL) outcomes following treatment of vestibular schwannoma (VS) using stereotactic radiosurgery (SRS).Study DesignProspective longitudinal study.SettingTertiary academic center.MethodsPatients who were treated for sporadic VS using SRS from 2015 to 2022 were included. QOL outcomes were measured using the disease‐specific Penn Acoustic Neuroma QOL (PANQOL) scale.ResultsSeventy‐nine patients with pre‐SRS and at least one post‐SRS PANQOL assessments were available for analysis. The mean change in total PANQOL scores was −2 (SD 13) on a 100‐point scale. The mean duration between assessments was 4.6 years (SD 2.0). Age at SRS, sex, and SRS treatment doses were not significantly associated with changes in total PANQOL scores. Total PANQOL scores improved a mean of 4 points for patients with tumors confined to the internal auditory canal but declined a mean of 5 points for patients with tumors extending into the cerebellopontine angle (P = .01); however, these changes did not exceed the minimum clinically significant threshold of 11 points. The correlation coefficient between treated tumor volume at SRS and change in total PANQOL scores was −0.30 (P = .007). Changes in PANQOL total (P = .5) and hearing domain (P = .3) scores for patients who maintained serviceable hearing or progressed to nonserviceable hearing did not significantly differ.ConclusionTumor extent and treated volume at SRS had a statistically significant but likely not clinically important impact on total PANQOL scores. Progression to nonserviceable hearing did not have a significant impact on PANQOL total or hearing domain scores.

Objective To compare the utility of intraoperative electrically evoked auditory brainstem response (eABR) and electrically evoked stapedial reflex testing (eSRT) for cochlear nerve integrity monitoring during simultaneous translabyrinthine resection of vestibular schwannoma (VS) and cochlear implantation. Study design Historical cohort study. Setting Tertiary academic referral center. Patients Eleven patients (12 cases) who underwent translabyrinthine tumor resection with simultaneous placement of a standard, unmodified cochlear implant (CI). Intervention A CI placed at the beginning of the operation before tumor resection to facilitate intraoperative cochlear nerve monitoring through a CI-delivered electrical stimulus. Main outcome measure Correlation of intraoperative monitoring outcomes with postoperative CI performance. Results Among the 12 cases (median age, 47 years), eABR waveforms were present at the conclusion of tumor resection in 10, including 6 that achieved open set speech perception. Of the 2 cases with negative eABR, 1 achieved open set speech perception. By contrast, of the 8 cases with a positive eSRT response, 7 achieved open set speech perception. Of the 4 cases with a negative eSRT response, none achieved open set speech perception. The 3 cases that did not receive auditory stimulation included 2 with positive and 1 with negative eABR; all 3 had a negative eSRT response. Conclusions Intraoperative eSRT using an unmodified CI is a promising new method for monitoring the integrity of the cochlear nerve during simultaneous VS resection. eSRT response at the conclusion of tumor resection strongly correlated with CI open set speech capacity. Although still useful, eABR was less reliable at predicting postoperative hearing outcomes in this series.

OBJECTIVE It is uncertain which cochlear dose parameters significantly impact hearing after stereotactic radiosurgery (SRS) for sporadic vestibular schwannoma (VS). The objective of this study was to determine the impact of cochlear dose parameters on hearing outcomes for patients with serviceable hearing (SH). METHODS This was a historical cohort study performed at a single tertiary center that included patients with sporadic VS and SH who underwent single-session Gamma Knife radiosurgery treatment from 2007 to 2022. Associations of cochlear dose parameters with time to non-SH and rates of change in pure-tone average (PTA) and word recognition score (WRS) following SRS were assessed. RESULTS A total of 205 patients with SH underwent SRS for a sporadic VS. At SRS, 54 (26%) tumors were confined to the internal auditory canal and 151 (74%) extended into the cerebellopontine angle. At 2, 5, and 10 years following SRS, 62%, 37%, and 15% of patients maintained SH, respectively. The median time to non-SH was 1.8 years. The median rates of change in PTA and WRS were 6.0 dB of hearing loss per year and −6.5% per year, respectively. In a multivariable analysis, each 1-Gy increase in minimum cochlear dose was significantly associated with time to non-SH (HR 1.5, 95% CI 1.2–1.9), rate of change in PTA decibel hearing loss per year (parameter estimate [PE] 3.4, 95% CI 0.6–6.2), and rate of change in WRS percentage per year (PE −6.4, 95% CI −11.2 to −1.5). The associations of each 1-Gy increase in mean cochlear dose with hearing outcomes were only significant among patients with class B hearing (time to non-SH HR 1.3, 95% CI 1.1–1.6; rate of change in PTA PE 3.6, 95% CI 1.2–5.9; and rate of change in WRS PE −5.7, 95% CI −9.7 to −1.7). CONCLUSIONS The minimum cochlear dose impacts hearing outcomes after SRS for VS and should be considered in radiosurgical treatment planning. In this cohort, the mean cochlear dose was only associated with hearing outcomes in the subgroup of patients with class B hearing at SRS.

AbstractObjectiveStereotactic radiosurgery (SRS) is increasingly used for small‐to‐medium‐sized sporadic vestibular schwannoma (VS) and is associated with good tumor control and low‐risk of adverse radiation‐associated events. The exact mechanism of VS tumor control is unknown but may relate to microvascular hyalinization and resultant tumoral ischemia. This study examined associations of microvascular risk factors with outcomes following SRS.DesignHistorical cohort of patients who underwent SRS for sporadic VS from 2000 to 2022.SettingTertiary academic center.MethodsAssociations of microvascular risk factors with tumor control and complications were evaluated using Cox proportional hazards regression.ResultsIn total 749 patients were studied, 31% with a history of smoking, 38% obesity, 19% hypertension, 8% diabetes, 3% peripheral vascular disease, and 2% history of coronary bypass. Regarding tumor control, no factor was associated with salvage treatment following SRS (n = 42). Hypertension (hazard ratio [HR] 2.81; P = .02) and coronary bypass (HR 6.91; P = .002) were significantly associated with developing facial nerve paresis (n = 22). No significant associations with new facial spasms (n = 53) were identified. Lastly, 191 of 294 patients with serviceable hearing at SRS progressed to nonserviceable hearing at a median 2.0 years (interquartile range: 1.0‐5.0). After multivariable adjustment for age and ipsilateral hearing status, the HR for the association of smoking history with time to nonserviceable hearing was 1.46 (95% confidence interval 1.04‐2.04; P = .03).ConclusionWe demonstrate that hypertension and history of coronary bypass may be associated with development of facial nerve weakness, while smoking may be associated with accelerated hearing loss in patients undergoing SRS for sporadic VS. These data may help guide patient counseling and inform decision‐making regarding treatment.

AbstractObjectiveTo evaluate tumor control and facial nerve outcomes after gross‐total (GTR), near‐total (NTR), and subtotal resection (STR) of sporadic vestibular schwannomas (VS).Data SourcesPubMed, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus databases were searched in August 2021 through inception following PRISMA guidelines.Review MethodsEnglish language articles reporting tumor control and facial nerve outcomes of adults (≥18 years) with NTR and STR of VS were evaluated. Study characteristics, demographics data, tumor characteristics, type of surgical intervention, and outcome measures on tumor control and facial nerve function were collected. Pooled relative risk (RR) estimates for tumor recurrence and facial nerve outcomes were calculated and stratified by extent of resection.ResultsFrom an initial search of 2504 articles, 48 studies were included in the analysis. When comparing 1108 patients who underwent NTR to 3349 patients with GTR, the pooled RR of recurrence in the NTR cohort was 2.94 (95% confidence interval [CI] 1.65‐5.24, P = .0002). When comparing 1016 patients who underwent STR to 6171 patients with GTR, the pooled RR of recurrence in the STR cohort was 11.50 (95% CI 6.64‐19.92, P < .0001). Estimates for risk of tumor regrowth for less‐than‐complete resection are presented. There was no elevated risk of adverse facial nerve outcome (defined as House‐Brackmann grade III and above) in each category of extent of resection compared to GTR.ConclusionExtent of resection predicts risk of tumor recurrence/regrowth following microsurgical resection. Favorable facial nerve outcome should be weighed against the increased risk of regrowth and the potential need for further treatment.

Objective To assess magnetic resonance imaging (MRI) safety of stapes prostheses. Data Sources Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus databases were searched from inception to November 2021 following PRISMA guidelines. Review Methods Studies reporting evidence of stapes prosthesis displacement or interaction in adult or pediatric implant recipients undergoing MRI. Cadaveric, animal, and basic studies with nonhuman data were also included. Results From an initial search of 123 articles, 42 full-text studies were evaluated for eligibility and 19 studies that met the inclusion criteria were included. Motion artifact was reported in a few stainless steel prosthesis types in vitro; however, such displacement was not observed in human cadaver temporal bone studies and had no adverse reported outcomes. A small subgroup of patients in the 1980s received a ferromagnetic stainless steel stapes implant that was recalled and has not been used since 1987. Patients with implants performed in the 1980s should be directed to 1.5T scanners from an abundance of caution. Conclusion Modern (post-1987) stapes prostheses do not pose a risk in vivo when exposed to the magnetic fields of MRI scanners.

Objective The treatment paradigm of vestibular schwannoma (VS) focuses on preservation of neurologic function, with small tumors increasingly managed with active surveillance. Often, tumor size and hearing outcomes are poorly correlated. The aim of the current work was to describe the natural history of hearing among patients with nongrowing VS during observational management. Study Design Historical cohort study. Patients Adults with sporadic VS. Intervention Wait-and-scan management. Main Outcome Measure Maintenance of serviceable hearing (SH) after diagnosis. Results Among 228 patients with nongrowing VS, 157 patients had SH at diagnosis. Rates of maintaining SH (95% CI; number still at risk) at 1, 3, and 5 years after diagnosis were 94% (89–98; 118), 81% (74–89; 65), and 78% (71–87; 42), respectively. Poorer hearing at diagnosis (hazard ratio [HR] per 10 dB hearing level increase in pure-tone average of 2.51, p < 0.001; HR per 10% decrease in word recognition score of 1.70, p = 0.001) was associated with increased likelihood of developing non-SH during observation. When controlling for baseline hearing status, tumors measuring 5 mm or greater in the internal auditory canal or with cerebellopontine angle extension were associated with significantly increased risk of developing non-SH (HR, 4.87; p = 0.03). At 5 years after diagnosis, 95% of patients with nongrowing intracanalicular VS measuring less than 5 mm maintained SH. Conclusions Hearing worsens during periods of nongrowth in sporadic VS. Patients with small (<5 mm) intracanalicular tumors demonstrate robust maintenance of SH over time, reinforcing the consideration of initial observation in this patient subset.

Objective To assess spatial hearing, tinnitus, and quality-of-life outcomes in adults with single-sided deafness (SSD) who underwent cochlear implantation. Databases Reviewed PubMed, MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus databases were searched from January 2008 to September 2021 following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Methods Studies reporting spatial hearing, tinnitus, and quality-of-life outcomes in adult cochlear implant (CI) recipients (≥18 yr old) with SSD were evaluated. Study characteristics, demographic data, spatial hearing (speech recognition in noise, sound source localization), tinnitus (severity, loudness), and quality-of-life outcomes were collected. Results From an initial search of 1,147 articles, 36 studies that evaluated CI use in 796 unique adults with SSD (51.3 ± 12.4 yr of age at time of implantation) were included. The mean duration of deafness was 6.2 ± 9.6 years. There was evidence of improvement for speech recognition in noise using different target-to-masker spatial configurations, with the largest benefit observed for target-to-masker configurations assessing head shadow (mean, 1.87–6.2 dB signal-to-noise ratio). Sound source localization, quantified as root-mean-squared error, improved with CI use (mean difference [MD], −25.3 degrees; 95% confidence interval [95% CI], −35.9 to −14.6 degrees; p < 0.001). Also, CI users reported a significant reduction in tinnitus severity as measured with the Tinnitus Handicap Inventory (MD, −29.97; 95% CI, −43.9 to −16.1; p < 0.001) and an improvement in spatial hearing abilities as measured with the Spatial, Speech, and Qualities of Hearing questionnaire (MD, 2.3; 95% CI, 1.7 to 2.8; p < 0.001). Conclusions Cochlear implantation and CI use consistently offer improvements in speech recognition in noise, sound source localization, tinnitus, and perceived quality of life in adults with SSD.