Improved Cervical Lymph Node Characterization among Patients with Head and Neck Squamous Cell Carcinoma Using MR Texture Analysis Compared to Traditional FDG-PET/MR Features Alone.

Accurate differentiation of benign and malignant cervical lymph nodes is important for prognosis and treatment planning in patients with head and neck squamous cell carcinoma. We evaluated the diagnostic performance of magnetic resonance image (MRI) texture analysis and traditional 18F-deoxyglucose positron emission tomography (FDG-PET) features. This retrospective study included 21 patients with head and neck squamous cell carcinoma. We used texture analysis of MRI and FDG-PET features to evaluate 109 histologically confirmed cervical lymph nodes (41 metastatic, 68 benign). Predictive models were evaluated using area under the curve (AUC). Significant differences were observed between benign and malignant cervical lymph nodes for 36 of 41 texture features (p < 0.05). A combination of 22 MRI texture features discriminated benign and malignant nodal disease with AUC, sensitivity, and specificity of 0.952, 92.7%, and 86.7%, which was comparable to maximum short-axis diameter, lymph node morphology, and maximum standard uptake value (SUVmax). The addition of MRI texture features to traditional FDG-PET features differentiated these groups with the greatest AUC, sensitivity, and specificity (0.989, 97.5%, and 94.1%). The addition of the MRI texture feature to lymph node morphology improved nodal assessment specificity from 70.6% to 88.2% among FDG-PET indeterminate lymph nodes. Texture features are useful for differentiating benign and malignant cervical lymph nodes in patients with head and neck squamous cell carcinoma. Lymph node morphology and SUVmax remain accurate tools. Specificity is improved by the addition of MRI texture features among FDG-PET indeterminate lymph nodes. This approach is useful for differentiating benign and malignant cervical lymph nodes.

High-resolution cone-beam computed tomography for assessment of bone invasion in oral cancer: Comparison with conventional computed tomography.

BACKGROUND: Radiologic assessment of mandibular bone invasion is critical in evaluating the extent of bone resection required in patients with oral cancer. There are a few reports of improved sensitivity with cone-beam CT (CBCT) over conventional CT. METHODS: A prospective cohort study of patients with oral squamous cell carcinomas adjacent to the mandible requiring marginal or segmental mandibular resection was performed. Patients were treated based on clinical assessment and conventional cross-sectional imaging. Patients and surgeons were blinded to the results of CBCT performed preoperatively. Pathologic examination served as the gold standard. RESULTS: Forty-five patients were included in the study. Thirty-three percent of the patients underwent segmental mandibulectomy and 37% had bone invasion. The sensitivity and specificity of CBCT were 91% and 60%, respectively, compared to 86% and 68% for CT with bone windows. CONCLUSION: A CBCT offers marginally improved sensitivity at the cost of reduced specificity for assessment of bone invasion compared to CT.

Staging cutaneous squamous cell carcinoma metastases to the parotid gland.

OBJECTIVE: The staging of cutaneous squamous cell cancers (cSCC) was revised by the American Joint Committee on Cancer in 2010 to incorporate known prognostic factors and expand the N (node) category. The purpose of this study was to validate this staging system using a North American cohort, and to compare it to the O'Brien P (Parotid) and N staging system. METHODS: An exhaustive collaborative database search was performed for all patients with cSCC metastasis to the parotid gland treated at three major Canadian tertiary referral centers from December 1999 to March 2015. The data collected for each patient included overall survival; disease-free survival; tumor, node, and metastasis) staging; and postoperative radiation status. Post-hoc analysis was completed to discern the strongest prognostic factors of survival as they relate to the abovementioned staging systems. RESULTS: Of 136 patients identified, 80% had a documented history of previously treated head and neck cSCC an average of 27 months prior to presentation. Average size of the parotid lesion at recurrence was 4.5 cm. Ninety-six percent of patients underwent surgical resection of the parotid metastasis. Five-year overall and disease-free survival is 79% and 55%, respectively. Only cSCC staging and cSCC-N category had statistically significant differences between groups. cSCC staging had the largest percentage of variation in overall survival explained. CONCLUSION: Patients with cSCC metastasis to the parotid gland proved to have a moderate survival rate, despite presenting with advanced disease. cSCC staging in the setting of parotid metastasis, despite its limitations, currently offers the most predictive staging system available. LEVEL OF EVIDENCE: 4. Laryngoscope, 127:2063-2069, 2017.

Summary of proceedings of the second World Congress on Thyroid Cancer.

The second World Congress on Thyroid Cancer was held from July 10 to July 14, 2013, in Toronto, Canada. Its purpose was to provide a platform for the multidisciplinary discussion on research, education, and patient management of thyroid malignancy. Herein, we summarize the latest major trends and controversies within the field of thyroid oncology as discussed in the Congress including the use of ultrasound, standardization of cytology, role of molecular testing, treatment options for small recurrence including ablation and observation, management of recurrent laryngeal nerve injury, importance of identification of the external branch of the superior laryngeal nerve, role of minimally invasive thyroid surgery, trends in radioactive iodine treatment, advancements in targeted agents, and the importance of personalizing treatment to individual patients.

Liquid accumulation in vibrating vocal fold tissue: a simplified model based on a fluid-saturated porous solid theory.

The human vocal fold is treated as a continuous, transversally isotropic, porous solid saturated with liquid. A set of mathematical equations, based on the theory of fluid-saturated porous solids, is developed to formulate the vibration of the vocal fold tissue. As the fluid-saturated porous tissue model degenerates to the continuous elastic tissue model when the relative movement of liquid in the porous tissue is ignored, it can be considered a more general description of vocal fold tissue than the continuous, elastic model. Using the fluid-saturated porous tissue model, the vibration of a bunch of one-dimensional fibers in the vocal fold is analytically solved based on the small-amplitude assumption. It is found that the vibration of the tissue will lead to the accumulation of excess liquid in the midmembranous vocal fold. The degree of liquid accumulation is positively proportional to the vibratory amplitude and frequency. The correspondence between the liquid distribution predicted by the porous tissue theory and the location of vocal nodules observed in clinical practice, provides theoretical evidence for the liquid accumulation hypothesis of vocal nodule formation (Jiang, Ph.D., dissertation, 1991, University of Iowa).

A-P positioning of medialization thyroplasty in an excised larynx model.

HYPOTHESIS: Posterior positioning of medialization thyroplasty provides the best acoustic and aerodynamic outcomes. STUDY DESIGN: Ex vivo excised canine larynx. METHODS: Unilateral thyroplasty windows were cut in the thyroid cartilages of 10 excised canine larynges. Each larynx was mounted on an artificial lung and the vocal fold opposite the thyroid window was adducted by medializing its arytenoid cartilage. Then, medialization thyroplasty was simulated with a probe placed anterior, central, and posterior in the thyroid window. The glottal area, airway reduction, medialization force, phonation threshold pressure and flow, aerodynamic power, intensity, efficiency, jitter, shimmer, and signal-to-noise ratio (SNR) were measured at each medialization position. RESULTS: Posterior medialization probe placement minimized the glottal area, provided the best voice as determined by perturbation measures and SNR, reduced the work of phonation, and increased efficiency. Anterior and middle probe placement minimized the work of phonation but provided only modest gains in sound quality and decreased sound intensity. Medializing the vocal fold with posterior probe placement required twice as much force as central and anterior probe placement. CONCLUSIONS: The results suggest that posterior medialization provides the greatest improvement in acoustic parameters and efficiency in patients who can tolerate the airway reduction. Middle and anterior medialization can decrease work of phonation, but in this experiment objective improvement in sound quality was limited. Subtle changes in displacement shim contour, especially in middle and anterior locations, have a substantial impact on voice outcome, affirming the value of intraoperative voice assessment.

A biphasic theory for the viscoelastic behaviors of vocal fold lamina propria in stress relaxation.

In this study, a biphasic theory is applied to investigate the viscoelastic behaviors of vocal fold lamina propria during stress relaxation. The vocal fold lamina propria tissue is described as a biphasic material composed of a solid phase and an interstitial fluid phase. The biphasic theory reveals the interaction between the solid and the fluid. For the one-dimensional case, the analytical solutions of solid displacement, fluid velocity, and stress are derived. The biphasic theory predicts the stress relaxation of the vocal fold lamina propria. The quasilinear viscoelastic model as well as its higher-order elastic parameters can be derived from this biphasic theory. Furthermore, the fluid is found to support the majority of the stress at the early stage of stress relaxation; however, when the time becomes sufficiently large, the solid eventually bears all the stress. The early fluid stress support is much higher than the eventual solid support and may be important for understanding the effects of dehydration on tissue damage. By considering the solid-fluid structure of the vocal fold lamina propria, the biphasic theory allows for a more physical theory of tissue viscoelasticity than a single phase solid description and may provide a valuable physical mechanism for the observed vocal fold rheologic behaviors.

Vocal nodules and edema may be due to vibration-induced rises in capillary pressure.

HYPOTHESIS: Vocal fold vibration may physically raise intravascular pressure to levels high enough to damage capillaries and result in leakage of erythrocytes. This type of injury is commonly seen in benign vocal fold lesions and is not well explained. STUDY DESIGN: Theoretical, retrospective. METHODS: The relationship of intravascular pressure to vibration frequency and amplitude is derived and confirmed with a physical blood vessel model, then applied to published human measurements to estimate human intravascular pressures. RESULTS: Vocal fold intravascular pressure is predicted to have a quadratic dependence on both frequency and amplitude. During speaking, the pressure may rise to over 20 cmH2O, and may reach levels far higher for screaming and singing. Such pressure magnitudes are known to trigger inflammatory cascades and can lead to fluid leakage. They also have the potential for pharmacologic control with beta-agonists. CONCLUSIONS: Intravascular pressure likely rises significantly during vocal fold vibration and may lead to the type of injury seen in benign vocal fold lesions. The results support voice therapy aimed at reducing vibratory amplitude. More vibratory amplitude measurements need to be performed in a wider range of subjects before the full range of human vocal fold vascular pressures can be estimated.