Quantitative Analysis of Temporal Bone Density and Thickness for Robotic Ear Surgery.

Background and Objective: Quantitative assessment of bone density and thickness in computed-tomography images offers great potential for preoperative planning procedures in robotic ear surgery. Methods: We retrospectively analyzed computed-tomography scans of subjects undergoing cochlear implantation (N = 39). In addition, scans of Thiel-fixated ex-vivo specimens were analyzed (N = 15). To estimate bone mineral density, quantitative computed-tomography data were obtained using a calibration phantom. The temporal bone thickness and cortical bone density were systematically assessed at retroauricular positions using an automated algorithm referenced by an anatomy-based coordinate system. Two indices are proposed to include information of bone density and thickness for the preoperative assessment of safe screw positions (Screw Implantation Safety Index, SISI) and mass distribution (Column Density Index, CODI). Linear mixed-effects models were used to assess the effects of age, gender, ear side and position on bone thickness, cortical bone density and the distribution of the indices. Results: Age, gender, and ear side only had negligible effects on temporal bone thickness and cortical bone density. The average radiodensity of cortical bone was 1,511 Hounsfield units, corresponding to a bone mineral density of 1,145 mg HA/cm3. Temporal bone thickness and cortical bone density depend on the distance from Henle's spine in posterior direction. Moreover, safe screw placement locations can be identified by computation of the SISI distribution. A local maximum in mass distribution was observed posteriorly to the supramastoid crest. Conclusions: We provide quantitative information about temporal bone density and thickness for applications in robotic and computer-assisted ear surgery. The proposed preoperative indices (SISI and CODI) can be applied to patient-specific cases to identify optimal regions with respect to bone density and thickness for safe screw placement and effective implant positioning.

Outcome of Salvage Therapy in Isolated Regional Recurrence in Head and Neck Squamous Cell Carcinoma.

OBJECTIVES/HYPOTHESIS: Head and neck squamous cell carcinoma (HNSCC) has a high tendency for regional lymphatic spreading. Nevertheless, isolated regional lymph node recurrences are rare, and only limited data regarding its management are available. The aim of this study was to describe treatment modalities and outcomes, and to identify prognostic factors. Study Design Retrospective cohort study. METHODS: The records of all patients (n = 498) with tumor persistence or recurrence after curatively intended treatment for HNSCC were retrospectively reviewed. Patients with synchronous secondary tumors at initial presentation, tumor persistence, local or locoregional recurrence, and systemic metastases were excluded. RESULTS: A total of 76 patients were included. The rate of occult additional metastasis in radiologically uninvolved neck compartments during salvage neck dissection was 25%. The salvaged patients showed a 37.5% 5-year recurrence-free survival (RFS). Multivariate analysis revealed initial stage IVA-B (hazard ratio [HR]: 4.16, P < .01), extracapsular spread (HR: 3.71, P = .04), higher involved/total lymph node ratio (HR: 6.79, P < .01), and soft-tissue infiltration (HR: 3.27, P < .01) as independent adverse prognostic factors for RFS. Moreover, univariate data analysis identified recurrent stage rcN2-3; clinical involvement of the neck levels IV, V and/or VI; and smoking as adverse risk factors for RFS. CONCLUSIONS: This study identifies initial stage IVA-B, extracapsular spread, higher involved/total lymph node ratio, and soft-tissue infiltration as independent adverse prognostic factors for RFS following isolated regional recurrences. The incidence of occult additional metastasis of radiologically uninvolved levels during salvage neck dissections was high (25%). Therefore, superselective or selective neck dissection would not have been the adequate type of salvage surgery. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:67-72, 2021.

Predicting Factors for Oncological and Functional Outcome in Hypopharyngeal Cancer.

OBJECTIVES/HYPOTHESIS: Hypopharyngeal squamous cell carcinoma (SCC) is a rare but aggressive malignancy, with low survival rates and high incidence of tumor and treatment-related morbidity. This study aims to analyze the long-term oncologic and functional outcomes of a large cohort of patients and to determine prognostic factors. STUDY DESIGN: Retrospective cohort study. METHODS: The records of all patients diagnosed with hypopharyngeal SCC and treated with curative intent at our tertiary referral center were reviewed. Patient and initial disease characteristics, features, and complications of primary treatment, recurrence patterns, and corresponding treatments and the oncologic and functional long-term outcome were determined. RESULTS: For a total of 179 patients, primary radiotherapy (RT) was the predominant treatment modality (78%), whereas 22% underwent primary surgery. The median, 2-year, and 5-year overall survival (OS) for the study cohort were 47 months, 64% and 43%. The median survival after first and second relapse was 7 and 6 months, respectively. The 2 and 5-year relapse-free survival (RFS) was 52% and 36%. The median RFS after first relapse and salvage treatment was 9 months. A nodal status of ≥cN2 (HR = 1.89, CI:1.21-3.05, P < .005) and any other primary tumor localization than pyriform sinus (HR = 1.60, CI: 1.04-2.42, P < .05) were identified as independent risk factors for shorter OS and RFS. Regarding functional outcome, the 2- and 5-year laryngectomy-free-survival was 55% and 37%, respectively. CONCLUSIONS: In this large cohort with long-term follow-up, any other primary tumor localization than pyriform sinus and a nodal status of ≥cN2 were identified as risk factors for reduced OS and RFS. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1543-E1549, 2021.

Risk analysis for tracheostomy dependency in curatively treated laryngeal cancer with organ preservation.

BACKGROUND: A tracheostomy has an enormous negative impact on the patient's quality of life. The purpose of this study is to describe risk factors for permanent tracheostomies in patients undergoing curative organ-preserving treatment of laryngeal cancer. METHODS: The charts of all patients with laryngeal cancer diagnosed at our tertiary referral center were reviewed. Cases receiving a tracheostomy before, during, or after primary organ-preserving treatment were eligible. RESULTS: A total of 87 patients who underwent tracheostomies were enrolled in the present study. During follow-up, 48 patients (55%) required a permanent tracheostomy, whereas 39 patients (45%) were decannulated. Multivariate analysis revealed primary radiotherapy (RT; odds ratio [OR] 12.857; P < .001) and recurrence (OR 25.84; P < .001) as independent factors of permanent tracheostomy. CONCLUSION: This study identifies primary curative RT and tumor relapse as independent risk factors of permanent tracheostomy dependency in patients with laryngeal cancer undergoing a tracheostomy during or after primary curative organ-preserving treatment.