Babajanian, Eric E.

Abstract Background Evaluation of middle ear prostheses requires high-resolution imaging to assess position and structural integrity. Purpose To assess the diagnostic performance of photon-counting-detector (PCD)-CT for middle ear prosthesis imaging in cadaveric specimens. Materials and Methods Nine different middle ear prostheses were implanted in five fresh-frozen whole-head specimens, both in correct anatomic position and displaced to mimic malposition. Specimens were scanned on PCD-CT (NAEOTOM Alpha, Siemens) and energy-integrating-detector (EID)-CT (SOMATOM Force, Siemens), reconstructed at 0.2mm and 0.4mm, respectively. Eighteen cases (9 prostheses, 2 positions) per scanner were evaluated by two neuroradiologists (36 readings), blinded to scanner and position, who scored prosthesis position, reader confidence, and overall image quality. Agreement with the reference standard and between readers was compared. Results PCD-CT showed higher diagnostic confidence compared with EID-CT, while accuracy and inter-reader agreement did not demonstrate significant differences between scanners. Correct readings, PCD-CT versus EID-CT: lateral contact, 31/36 (86.1%; 95% CI: 58.3%-94.4%) vs. 29/36 (80.6%; 55.6%-91.7%), p = 0.500; medial contact, 30/36 (83.3%; 55.6%-94.4%) vs. 26/36 (72.2%; 50.0%-83.3%), p = 0.250. PCD-CT identified all cases of complete contact loss (score 3), while EID-CT missed one reading per contact. Inter-reader agreement may be higher with PCD-CT vs EID-CT (lateral: κw: 0.804 [0.578-0.941] vs. 0.571 [0.302-0.778], p = 0.250; medial: 0.684 [0.191-0.934] vs. 0.481 [0.024-0.835], p = 0.250). Reader confidence was significantly higher with PCD-CT; mean paired differences for Readers 1 and 2 were 9.4 (1.8-17.1; Holm-adjusted p = 0.019) and 23.1 points (13.4-32.7; p < 0.001) for lateral contact, and 16.4 (10.0-22.8; p < 0.001) and 17.8 points (6.8-28.8; p = 0.007) for medial contact. Readers preferred PCD-CT image quality in 16/18 (88.9%; 65.3%-98.6%) and 17/18 cases (94.4%; 72.7%-99.9%), respectively. Conclusion PCD-CT was associated with significantly higher reader confidence and preferred image quality, without significant differences in diagnostic accuracy or inter-reader agreement. These findings suggest PCD-CT is a promising modality for postoperative middle ear evaluations that warrants further investigations.

ABSTRACT Background Unknown primary cancer in the head and neck presents a difficult surgical treatment dilemma. Patients with squamous cell carcinoma of unknown primary (SCCUP) typically present with an enlarging neck mass found on biopsy but with no indication of primary site on diagnostic exams such as flexible laryngoscopy, CT, MRI, and/or PET/CT. Failure to identify primary sites eliminates surgical treatment as an option, pushing patients toward definitive chemoradiation with associated side effects. Methods Indocyanine green (ICG) has been used to identify primary carcinoma in known oropharyngeal squamous cell carcinoma while using transoral robotic surgery (TORS). In this case, we injected ICG intraoperatively in a patient with SCCUP to help with the real‐time localization of ICG in the tumor. Results ICG fluorescence successfully identified a previously undetected primary lesion within the oropharynx during TORS, which enabled precise surgical excision of the tumor. Conclusions This case demonstrates the potential of ICG‐guided TORS to localize primary tumors in SCCUP patients, offering a pathway to surgical treatment and potentially reducing reliance on chemoradiation.

Objective: To examine the benefit of cochlear implantation (CI) in pediatric patients with a history of temporal bone fracture resulting in single-sided deafness (SSD). Study design: Retrospective chart review. Setting: Two tertiary academic centers. Patients: Pediatric patients less than 18 years of age with SSD secondary to temporal bone fracture who underwent CI from 2012 to 2022. Intervention(s): CI. Main outcome measure(s): Postoperative audiometric testing. Results: Seven subjects were identified (median age: 10 years (y); Q1 to Q3: 5 to 16 y). Median time from temporal bone trauma to CI was 7 months (mo) (Q1 to Q3: 3 to 7 mo) and 85% had otic capsule involvement. Subjects were followed for a median length of 12 months (Q1 to Q3: 6 to 24 mo) after CI. All patients achieved full electrode insertion, though 2 required scala vestibuli insertion due to ossification of the scala tympani (one of whom had a history of meningitis after temporal bone fracture). Postoperative audiometric testing revealed variable speech perception outcomes with 4 of 7 obtaining open or closed set speech perception and 3 of 7 obtaining only sound awareness. No postoperative complications occurred. Conclusions: CI is a feasible intervention for SSD following pediatric temporal bone fractures, but outcomes are variable. Early evaluation and timely CI, ideally within 6 months of temporal bone fracture, may optimize outcomes. Cochlear ossification, either as a result of otic capsule fracture or subsequent meningitis, may lead to suboptimal outcomes.

Objective: Auditory nerve monitoring through electrically evoked compound action potentials (eCAP) can be used to assess cochlear neural integrity during vestibular schwannoma (VS) resection. Herein, we report on 5 cochlear implant (CI) patients who underwent VS resection with present eCAP responses both intraoperatively and postoperatively. Patients either did not perceive any sound through their CI or rapidly adapted to electrical stimulation, suggesting that the presence of eCAP does not guarantee auditory nerve function in patients with VS resection. Patients: Five patients who underwent simultaneous VS translabyrinthine resection and cochlear implantation. Interventions: Simultaneous cochlear implantation and translabyrinthine microsurgical VS resection. Main outcome measure: Electrically evoked compound action potential. Results: All patients had eCAP responses present during their VS resection and for at least 50 days post-surgery. Three of the 5 patients did not perceive any sound with their cochlear implant. This shows that the presence of an eCAP alone does not guarantee a functional auditory nerve or auditory perception. The other 2 patients could hear non-speech sounds, but these sounds quickly became inaudible, indicating that their auditory nerve lacked the ability to integrate the electrical stimulus over time. Conclusions: The presence of an eCAP response does not guarantee auditory sensation through a CI. Although eCAP measurements provide insight into the function of the distal end of the nerve, it does not ascertain integrity or function of the larger auditory nerve pathway. Therefore, eCAPs should not be used in isolation to monitor auditory nerve function during VS resection.

OBJECTIVE The objective of this study was to describe the long-term efficacy of single-fraction stereotactic radiosurgery (SRS) for the primary treatment of sporadic vestibular schwannoma. METHODS Adult (≥ 18 years of age) patients with sporadic vestibular schwannoma who underwent SRS from 2000 through 2022 were included. RESULTS A total of 749 patients met inclusion criteria, the majority (n = 566, 76%) of whom had tumors extending into the cerebellopontine angle at SRS. The median patient age at SRS was 62 years, half (50%) of the patients were women, and 744 (99%) exhibited House-Brackmann grade I facial nerve function at SRS. A total of 42 patients experienced radiosurgical failure and underwent salvage treatment; the median duration of follow-up for the patients who did not undergo salvage treatment was 7.0 years. Overall tumor control rates (95% CI, number still at risk) at 1, 3, 5, 10, and 15 years after SRS were 100% (100%–100%, 718), 98% (97%–99%, 589), 96% (94%–97%, 464), 92% (90%–95%, 258), and 91% (89%–94%, 125), respectively. Patient age (hazard ratio [HR] for a 10-year increase of 0.92, 95% CI 0.71–1.19; p = 0.5), presence of a macrocystic tumor (HR 0.59, 95% CI 0.14–2.46; p = 0.5), and treated tumor volume (HR for a 1-cm 3 increase of 1.02, 95% CI 0.88–1.18; p = 0.8) were not significantly associated with the risk of salvage. Three distinct post-SRS tumor behavior patterns were observed, with 13% of patients demonstrating tumor pseudoprogression, all but 4 of whom demonstrated pseudoprogression by year 5 post-SRS. CONCLUSIONS SRS demonstrates durable tumor control through 15 years of follow-up in most patients (91%); however, a minority are found to still experience SRS failure even beyond 10 years of surveillance. Although occurring in only a minority of patients, tumor pseudoprogression can be evident out to 5 years or longer post-SRS.

OBJECTIVE Wait-and-scan surveillance is now commonly employed for initial management of small- and medium-sized vestibular schwannomas. Although small differences in tumor size are unlikely to impact outcomes significantly, treatment with either radiosurgery or microsurgery is usually recommended following radiological detection of tumor growth. The objective of the current study was to identify potential inflection points in vestibular schwannoma tumor size, where the risks of treatment with single-fraction stereotactic radiosurgery (SRS) accelerate to inform timing of intervention. METHODS Adult (≥ 18 years old) patients with sporadic vestibular schwannoma who underwent SRS from 2000 through 2022 were included. RESULTS A total of 749 patients with a median age at SRS of 62 years were studied, the majority (n = 566 [76%]) of whom had tumors extending into the cerebellopontine angle (CPA) at SRS. The optimal tumor size cut point to predict SRS failure and need for salvage treatment was 4 mm or more of CPA extension (c-index 0.59, HR 3.60, p = 0.01). The optimal tumor size cut point to predict the outcome of facial nerve paresis was 13 mm or more of CPA extension, resulting in a c-index of 0.63 (HR 2.88, p = 0.01). Among patients with at least 3 months of surveillance before SRS, those with a tumor growth rate ≥ 2.5 mm/year were more likely to undergo salvage treatment than those with a growth rate < 2.5 mm/year, although this difference did not achieve statistical significance (HR 1.82, p = 0.18). CONCLUSIONS The risk of SRS failure requiring salvage treatment and the risk of post-SRS facial nerve paralysis increase at sizes of approximately 4 and 13 mm extension into the CPA, respectively, providing a size threshold anchor to help guide treatment decision-making regarding timing of SRS. Furthermore, rapid tumor growth during the initial wait-and-scan period may be associated with an increased risk of radiosurgical failure, which may influence choice of treatment.

Objective: To examine the association of extent of otosclerotic plaque using high-resolution photon-counting computed tomography (PCCT) with hearing and surgical outcomes. Study design: Historical cohort. Setting: Large academic center. Patients: Patients with otosclerosis who completed PCCT imaging at time of initial evaluation. Interventions: Observation, surgery. Main outcome measures: Audiometric data. Results: A total of 53 ears were eligible for study. The mean age at PCCT was 51 years (SD: 14). The mean extent of oval window otosclerotic plaque measured in radial degrees was 112 (SD: 65) and the mean otosclerotic depth was 1.6mm (SD: 0.6). The mean air-bone gap pure-tone average was 18 dB (SD: 12) and the mean Carhart degree was 9 dB (SD: 10). The radial degrees of oval window extent were not significantly associated with air-bone gap (correlation coefficient: 0.14; P =0.3) or Carhart degree (correlation coefficient: 0.04; P =0.8). Likewise, otosclerotic plaque depth was not significantly associated with air-bone gap (correlation coefficient: −0.19; P =0.2) or Carhart degree (correlation coefficient: −0.08; P =0.6). After PCCT, 22 ears underwent surgery. In this subset, oval window extent and plaque depth were not significantly associated with the postoperative changes in air-bone gap or high-frequency thresholds. Conclusions: Despite enhanced visualization of subtle abnormalities with PCCT imaging, the extent of oval window otosclerotic plaque, measured in angular degrees and depth, was not associated with hearing loss at time of initial evaluation or postoperative audiologic changes in patients with otosclerosis.

Objective: To evaluate the impact of cochlear implantation (CI) and simultaneous endolymphatic sac decompression (ELSD) on vestibular and audiometric outcomes in patients with advanced Ménière disease (MD). Study design: Historical cohort. Setting: Tertiary academic medical center. Patients: Patients with medically refractory MD who underwent CI with or without simultaneous ELSD from 2000 through 2024. Interventions: CI with or without ELSD. Main outcome measures: Post-CI patient-reported changes in vertigo severity and frequency, Consonant-Nucleus-Consonant word (CNCw) scores, and AzBio sentences in quiet scores. Results: Ninety-nine patients with preoperative vertigo secondary to MD were eligible for study, including 17 (17%) who underwent simultaneous ELSD. In total, 15 (88%) and 2 (12%) of the 17 patients with simultaneous ELSD reported improvement and stability in vertigo severity, respectively; in comparison, 26 (32%), 40 (49%), and 16 (20%) of the 82 patients with CI alone reported improvement, stability, and worsening in vertigo severity, respectively ( P <0.001). Likewise, 15 (88%) and 2 (12%) of the patients with simultaneous ELSD reported improvement and stability in vertigo frequency, respectively, whereas 21 (26%), 43 (52%), and 18 (22%) of patients with CI alone reported improvement, stability, and worsening in vertigo frequency, respectively ( P <0.001). Post-CI speech recognition scores were not significantly different between the simultaneous ELSD and CI alone groups [median (IQR) CNCw 70 (38 to 82) vs. 72 (58 to 82) and median (IQR) AzBio quiet 87 (67 to 96) vs. 87 (73 to 94), respectively]. Conclusions: In patients with MD, CI with simultaneous ELSD provides improvement in vertigo symptoms and similar audiometric outcomes when compared with CI alone. In appropriately selected patients with both refractory vestibular symptoms and sensorineural hearing loss meeting criteria for implantation, CI with simultaneous ELSD offers improvement in severity and frequency of vertigo as well as successful auditory rehabilitation.

Objective: To characterize patient outcomes after primary stereotactic radiosurgery (SRS) for the management of sporadic facial nerve schwannoma. Study design: Retrospective cohort study. Setting: Six tertiary referral centers across the United States and United Kingdom. Patients: Adults undergoing SRS from 2000 through 2023 for sporadic facial nerve schwannoma along any segment of the facial nerve were included. Patients with NF2-related schwannomatosis were excluded. Intervention: Stereotactic radiosurgery. Main outcome measure: Long-term tumor control. Results: Among 60 patients meeting inclusion, the median age at SRS was 52 years (IQR: 41 to 64) with a median tumor size of 19.5 mm (IQR: 14.7 to 22.8). Tumors commonly involved the internal auditory canal (73%), cisternal (49%), geniculate/labyrinthine (47%), and tympanic segments (22%). Two patients experienced SRS failure and underwent salvage treatment; salvage-free survival rates (95% CI; number still at risk) at 1, 3, 5, and 10 years after SRS were 100% (100 to 100; 55), 100% (100 to 100; 36), 100% (100 to 100; 18), and 87% (72 to 100; 9), respectively. Among 31 (52%) patients with House-Brackmann (HB) grade I facial function at presentation, only 6 demonstrated worse facial function at a median of 3.2 years (IQR: 1.7 to 6.6) after SRS. Of 18 patients with serviceable hearing (AAO-HNS class A/B) at SRS, 13 maintained serviceable hearing at a median of 1.0 years (IQR: 0.5 to 4.9) of post-SRS audiometric follow-up. Conclusions: Durable tumor control after primary SRS for sporadic facial nerve schwannoma is achieved in most patients. Among those with HB grade I facial function at presentation, treatment with SRS harbors limited additional risk of facial paresis beyond observation alone.

Objective: Vestibular schwannomas (VSs) treated with stereotactic radiosurgery (SRS) often show transient loss of central tumor enhancement. We hypothesized that this loss of enhancement may correlate with better tumor control on follow-up imaging. Methods: We evaluated 198 consecutive patients from a single center who met eligibility criteria. Tumor volumes on the pre-SRS and post-SRS scans were quantified along with regions of loss of enhancement on the first post-SRS study. The latter was correlated with tumor volumes at follow-up, radiation isocenter density, and loss of serviceable hearing. Results: For the entire cohort, the median loss of enhancement on the first post-SRS scan was 14% (IQR: 6 to 25) and median rate of change in tumor volume was −4.5% per year (IQR: −10.5 to 1.5). Percent loss of central enhancement showed significant negative correlation with tumor growth not only for the entire cohort (correlation coefficient: −0.18, P =0.01), but also for the subset of patients who had available imaging until at least 2 years (n=185) and 4 years (n=179) post-SRS. Loss of enhancement also strongly correlated positively with tumor volumes and number of radiation isocenters and negatively with isocenter density. Finally, patients with greater percent loss of enhancement had an increased likelihood of progression to non-serviceable hearing, although this association was not statistically significant. Conclusions: These findings suggest that loss of central tumor enhancement in VSs post-SRS may be associated with improved tumor control.