Retroductal dexamethasone administration promotes the recovery from obstructive and inflammatory salivary gland dysfunction.

Introduction: Salivary gland dysfunction, often resulting from salivary gland obstruction-induced inflammation, is a prevalent condition. Corticosteroid, known for its anti-inflammatory and immunomodulatory properties, is commonly prescribed in clinics. This study investigates the therapeutic implications and potential side effects of dexamethasone on obstructive sialadenitis recovery using duct ligation mice and salivary gland organoid models. Methods: Functional and pathological changes were assessed after administering dexamethasone to the duct following deligation 2 weeks after maintaining ligation of the mouse submandibular duct. Additionally, lipopolysaccharide- and tumor necrosis factor-induced salivary gland organoid inflammation models were established to investigate the effects and underlying mechanisms of action of dexamethasone. Results: Dexamethasone administration facilitated SG function restoration, by increasing salivary gland weight and saliva volume while reducing saliva lag time. Histological evaluation revealed, reduced acinar cell atrophy and fibrosis with dexamethasone treatment. Additionally, dexamethasone suppressed pro-inflammatory cytokines IL-1ß and TNF expression. In a model of inflammation in salivary gland organoids induced by inflammatory substances, dexamethasone restored acinar markers such as AQP5 gene expression levels, while inhibiting pro-inflammatory cytokines TNF and IL6, as well as chemokines CCL2, CXCL5, and CXCL12 induction. Macrophages cultured in inflammatory substance-treated media from salivary gland organoid cultures exhibited pro-inflammatory polarization. However, treatment with dexamethasone shifted them towards an anti-inflammatory phenotype by reducing M1 markers (Tnf, Il6, Il1b, and Cd86) and elevating M2 markers (Ym1, Il10, Cd163, and Klf4). However, high-dose or prolonged dexamethasone treatment induced acino-ductal metaplasia and had side effects in both in vivo and in vitro models. Conclusions: Our findings suggest the effectiveness of corticosteroids in treating obstructive sialadenitis-induced salivary gland dysfunction by regulating pro-inflammatory cytokines.

A randomized comparison of three intubation techniques/tube materials for nasotracheal intubation.

PURPOSE: We sought to compare three intubation methods using different intubation techniques/tube materials for tube advancement from the nasal cavity into the oral cavity during nasotracheal intubation. METHODS: We conducted a randomized clinical trial with adult patients scheduled to undergo elective surgery requiring nasotracheal intubation for general anesthesia. Participants were randomly allocated to a polyvinyl chloride (PVC) tube group (group P), PVC tube attached to a rubber catheter group (group PR), or velvet-soft PVC tube group (group V). Tracheal intubation was then performed based on group allocation. The primary outcome was the first-attempt success rate of tube advancement into the oral cavity; secondary outcomes included the time required for tube advancement into the oral cavity, total intubation time, and the incidence of epistaxis. RESULTS: A total of 149 patients were included in the study. The first-attempt success rate in group V (90%) was significantly higher than that in group P (58%) (odds ratio, 6.5; 95% confidence interval [CI], 2.2 to 19.2), but similar to that in group PR (100%). The mean (standard deviation) time required for tube advancement into the oral cavity was significantly shorter in group V (16 [13] sec) than in group PR [40 (10) sec; 95% CI of mean difference, 17 to 30] and group P (26 [16] sec; 95% CI of mean difference, 3 to 16). Total intubation time was longest in group PR. Epistaxis occurred the least in group V. CONCLUSIONS: Among the three intubation techniques/tube materials for nasotracheal intubation, the velvet-soft PVC tube provided the highest first-attempt success rate, most expeditious advancement into the oral cavity, and lowest incidence of epistaxis. STUDY REGISTRATION: ClinicalTrials.gov (NCT04695444); first submitted 30 December 2020.

RéSUMé: OBJECTIF: Nous avons cherché à comparer trois méthodes d'intubation utilisant différentes techniques d'intubation / matériaux de sondes pour l'avancement de la sonde de la cavité nasale dans la cavité buccale pendant l'intubation nasotrachéale. MéTHODE: Des patient·es devant recevoir une intubation nasotrachéale ont été réparti·es au hasard dans un groupe avec sondes en polychlorure de vinyle (PVC) (groupe P), un groupe avec sondes en PVC attachées à un cathéter en caoutchouc (groupe PR) ou un groupe avec sondes en PVC doux comme du velours (groupe V). L'intubation trachéale a ensuite été réalisée en fonction de l'affectation du groupe. Le critère d'évaluation principal était le taux de réussite de la première tentative d'avancement de la sonde dans la cavité buccale; les critères d'évaluation secondaires comprenaient le temps nécessaire à l'avancement de la sonde dans la cavité buccale, la durée totale de l'intubation et l'incidence d'épistaxis. RéSULTATS: Au total, 149 patient·es ont été inclus·es dans l'étude. Le taux de réussite de l'intubation à la première tentative était significativement plus élevé dans le groupe V (90 %) que dans le groupe P (58 %) (rapport de cotes, 6,5; intervalle de confiance à 95 % [IC], 2,2 à 19,2), mais similaire à celui du groupe PR (100 %). Le temps moyen (écart type) nécessaire pour l'avancement de la sonde dans la cavité buccale était significativement plus court dans le groupe V (16 [13] sec) que dans le groupe PR (40 [10] sec; IC 95 % de la différence moyenne, 17 à 30) et dans le groupe P (26 [16] sec; IC 95 % de la différence moyenne, 3 à 16). La durée totale d'intubation était la plus longue dans le groupe PR. C'est dans le groupe V que l'épistaxis a été la moins fréquente. CONCLUSION: Parmi les trois techniques d'intubation/matériaux de sonde pour l'intubation nasotrachéale, le tube en PVC doux comme du velours a fourni le taux de réussite de première tentative le plus élevé, l'avancement le plus rapide dans la cavité buccale et l'incidence d'épistaxis la plus faible. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT04695444); première soumission le 30 décembre 2020.

The Usefulness of Salivary Gland Organoids for Evaluation of the Potency of Botulinum Neurotoxin.

BACKGROUND AND OBJECTIVES: Botulinum neurotoxin (BoNT) is a substance used to treat chronic sialorrhea, muscle dystonia, and is used in cosmetic applications. Measuring the potency of BoNT is crucial because it acts even with a small amount. However, the current methods for measuring the potency of BoNT involve using two-dimensional neuroblastoma cell line-based methods. In this study, we aimed to develop a new method to measure the potency of BoNT using a three-dimensional organoid culture system. MATERIALS AND METHOD: We established the optimal conditions for coculturing N2a neuronal cells with murine salivary gland organoids (SGOs). After determining the appropriate chemical concentrations, we treated the SGOs cocultured with N2a cells with BoNT type A (BoNT/A). We confirmed the expression of salivary gland-related genes and proteins using real-time polymerase chain reaction (PCR) and immunofluorescence staining. RESULTS: The SGOs cocultured with N2a cells showed that the dendrites or axons of neuronal cells were in contact with the outermost layer of the SGOs. When we applied acetylcholine and neostigmine to the coculture systems, the mRNA expression of Aqp5 and Bhlha15, associated with salivary gland secretory cells, increased. However, this effect was reversed when BoNT/A was applied, as confirmed through real-time PCR. CONCLUSION: We found that the coculture system of SGOs and N2a neuronal cells can potentially serve as a potency testing platform for BoNT. LEVEL OF EVIDENCE: NA Laryngoscope, 134:2697-2704, 2024.

Surgical margin status and role of adjuvant therapy in human papillomavirus-positive oropharyngeal cancer.

BACKGROUND: We analyzed the difference in treatment results according to safety margin range and studied the role of adjuvant therapy in patients with human papillomavirus-positive (HPV+) oropharyngeal squamous cell carcinoma (OPSCC). MATERIALS AND METHODS: A total of 279 patients with HPV+ OPSCC were included in this study. RESULTS: Surgical margin and T classification were significant prognostic factors related to death. The difference in locoregional recurrence was analyzed by dividing the safety margin into groups of <1, 1-5, and >5 mm. There was no significant difference in local-regional recurrence for T1-T2 lesions between the three groups. Adjuvant therapy can significantly reduce disease recurrence in HPV+ OPSCC patients with risk factors. CONCLUSIONS: In T1-T2 lesions without other risk factors, even with a safety margin ≥1 mm, adjuvant therapy can potentially be omitted. Adjuvant therapy can significantly reduce disease recurrence in HPV+ OPSCC patients with risk factors.

Ductal delivery of extracellular vesicles promote the recovery from salivary gland inflammation.

Salivary gland dysfunction worsens the quality of life, but treatment for restoration of salivary gland function is limited. Although previous reports have demonstrated the therapeutic potentials of extracellular vesicles (EVs) in different preclinical models, the role of EVs in salivary glands remains elusive. Furthermore, little is known about the roles of salivary gland-derived EVs in tissue repair or regeneration compared to other EVs. In this study, EVs secreted from salivary gland-derived mesenchymal stem cells (sgMSCs) were comparatively analyzed with those from Wharton's jelly-derived MSC (wjMSCs). sgMSCs secreted more significant amounts of EVs than wjMSCs, and salivary gland epithelial cells showed a more efficient uptake of sgMSC-EVs than wjMSC-EVs. The possibility of immune regulation was tested via macrophage polarization and LPS-induced epithelial inflammation, resulting in an M1-to-M2 shift and reversal of acinar-to-ductal metaplasia by sgMSC-EV. Furthermore, the roles of sgMSC-EV-mediated immune regulation and tissue repair were clarified in vivo via retroductal delivery of sgMSC-EVs in a mouse model of obstructive sialadenitis. Collectively, our data demonstrate the superior role of sgMSC-EVs in the recovery from salivary gland inflammation and injury and suggest EVs as therapeutic tools for salivary gland dysfunction.

Long-term outcomes of early stage oral tongue cancer: Main cause of treatment failure and second primary malignancy.

Objective: We attempted to investigate the long-term outcomes, prognostic factors, treatment failures, second primary malignancies, and salvage therapies in early (pT1-2N0) oral tongue squamous cell carcinoma (OTSCC). Methods: We retrospectively analyzed the medical records of 295 early stage OTSCC patients. Results: Two hundred ninety-five patients were enrolled. The average follow-up period was 64.5 months (range, 1-190 months). Five-year recurrence-free survival rate was 84.8% and disease-specific survival rate was 91.2%. On multivariate analysis, only the depth of invasion (DOI) exhibited significant correlations with the disease recurrence. Patient's age and DOI demonstrated a significant association with survival. A total of 53 recurrence and 35 death events occurred, with the main cause of treatment failure being regional or local recurrence. In recurrent cases, the success rate of salvage treatment was 42% at 5 years. During the follow-up period, second primary malignancy occurred in 13 patients, and 8 (61.5%) of those patients were successfully treated. Conclusions: In pT1-2N0 OTSCC, regional or local recurrence is the main recurrence pattern, whereas age and DOI >5 mm are significant prognostic factors related to recurrence and survival. Since several patients experienced second primary malignancies in the head and neck, careful and thorough surveillance may be required to detect second primary lesions. Level of Evidence: 4.

Salivary gland organoid culture maintains distinct glandular properties of murine and human major salivary glands.

Salivary glands that produce and secrete saliva, which is essential for lubrication, digestion, immunity, and oral homeostasis, consist of diverse cells. The long-term maintenance of diverse salivary gland cells in organoids remains problematic. Here, we establish long-term murine and human salivary gland organoid cultures. Murine and human salivary gland organoids express gland-specific genes and proteins of acinar, myoepithelial, and duct cells, and exhibit gland functions when stimulated with neurotransmitters. Furthermore, human salivary gland organoids are established from isolated basal or luminal cells, retaining their characteristics. Single-cell RNA sequencing also indicates that human salivary gland organoids contain heterogeneous cell types and replicate glandular diversity. Our protocol also enables the generation of tumoroid cultures from benign and malignant salivary gland tumor types, in which tumor-specific gene signatures are well-conserved. In this study, we provide an experimental platform for the exploration of precision medicine in the era of tissue regeneration and anticancer treatment.

Deep learning model for tongue cancer diagnosis using endoscopic images.

In this study, we developed a deep learning model to identify patients with tongue cancer based on a validated dataset comprising oral endoscopic images. We retrospectively constructed a dataset of 12,400 verified endoscopic images from five university hospitals in South Korea, collected between 2010 and 2020 with the participation of otolaryngologists. To calculate the probability of malignancy using various convolutional neural network (CNN) architectures, several deep learning models were developed. Of the 12,400 total images, 5576 images related to the tongue were extracted. The CNN models showed a mean area under the receiver operating characteristic curve (AUROC) of 0.845 and a mean area under the precision-recall curve (AUPRC) of 0.892. The results indicate that the best model was DenseNet169 (AUROC 0.895 and AUPRC 0.918). The deep learning model, general physicians, and oncology specialists had sensitivities of 81.1%, 77.3%, and 91.7%; specificities of 86.8%, 75.0%, and 90.9%; and accuracies of 84.7%, 75.9%, and 91.2%, respectively. Meanwhile, fair agreement between the oncologist and the developed model was shown for cancer diagnosis (kappa value = 0.685). The deep learning model developed based on the verified endoscopic image dataset showed acceptable performance in tongue cancer diagnosis.

Machine learning and magnetic resonance imaging radiomics for predicting human papilloma virus status and prognostic factors in oropharyngeal squamous cell carcinoma.

BACKGROUND: We attempted to predict pathological factors and treatment outcomes using machine learning and radiomic features extracted from preoperative magnetic resonance imaging (MRI) of oropharyngeal squamous cell carcinoma (OPSCC) patients. METHODS: The medical records and imaging data of 155 patients who were diagnosed with OPSCC were analyzed retrospectively. RESULTS: The logistic regression model showed that the area under the receiver operating characteristic curve (AUC) of the model was 0.792 in predicting human papilloma virus (HPV) status. The LightGBM model showed an AUC of 0.8333 in predicting HPV status. The performance of the logistic model in predicting lymphovascular invasion, extracapsular nodal spread, and metastatic lymph nodes showed AUC values of 0.7871, 0.6713, and 0.6638, respectively. In predicting disease recurrence, the LightGBM model showed an AUC of 0.8571. In predicting patient death, the logistic model showed an AUC of 0.8175. CONCLUSIONS: A machine learning model using MRI radiomics showed satisfactory performance in predicting pathologic factors and treatment outcomes of OPSCC patients.

Care and Management of Voice Change in Thyroid Surgery: Korean Society of Laryngology, Phoniatrics and Logopedics Clinical Practice Guideline.

Voice change is a common complaint after thyroid surgery and has a significant impact on quality of life. The Korean Society of Laryngology, Phoniatrics and Logopedics assembled a task force to establish guideline recommendations on education, care, and management related to thyroid surgery. The guideline recommendations encompass preoperative voice education, management of anticipated voice change during surgery, and comprehensive voice care after thyroid surgery, and include in-depth information and up-to-date knowledge based on validated literature. The committee constructed 14 key questions (KQs) in three categories-preoperative (KQ 1-2), intraoperative (KQ 3-8), and postoperative (KQ 9-14) management-and developed 18 evidence-based recommendations. The Delphi survey reached an agreement on each recommendation. A detailed evidence profile is presented for each recommendation. The level of evidence for each recommendation was classified as high-quality, moderate-quality, or low-quality. The strength of each recommendation was designated as strong or weak considering the level of evidence supporting the recommendation. The guidelines are primarily targeted toward physicians who treat thyroid surgery patients and speech-language pathologists participating in patient care. These guidelines will also help primary care physicians, nurses, healthcare policymakers, and patients improve their understanding of voice changes and voice care after thyroid surgery.

Predictive Factors Affecting the Outcomes Of angiolytic Laser-Assisted Glottoplasty for Sulcus Vocalis.

OBJECTIVE: Glottoplasty using an angiolytic laser is an option for the surgical treatment of sulcus vocalis. In this study, we sought to evaluate the clinical outcomes of using a 532-nm diode laser in sulcus vocalis patients and to identify predictive factors of improved voice outcomes after angiolytic laser-assisted glottoplasty. METHODS: A total of 66 patients with sulcus vocalis who underwent laser-assisted glottoplasty with a 532-nm diode laser were included in this study. RESULTS: 3 months after surgery, GRBAS scores, patient-reported outcome measures, fundamental frequency (F0), jitter percent, and noise-to-harmonic ratio decreased significantly, while cepstral peak prominence (CPP) of vowel and sentence production increased. Patients with auditory-perceptual improvements showed greater improvement in the Voice Handicap Index (VHI) scores, F0, and CPP of vowel and sentence production compared to those with no improvement. While young male patients with preoperatively high F0 were predicted to have favorable outcomes, the type of sulcus vocalis was not predictive of treatment outcomes. Patients treated with lower laser power showed better improvement in the VHI scores postoperatively than those who received higher laser power per vocal fold. Combined injection laryngoplasty with laser glottoplasty was effective in lowering the F0, especially in male patients with high F0. CONCLUSION: A 532-nm diode laser is useful for treating sulcus vocalis. Young male patients and individuals with preoperatively high F0 showed better voice outcomes after laser glottoplasty. Laser power and combined injection laryngoplasty are considered to affect improvement in the VHI and lowering F0 after laser glottoplasty in sulcus vocalis.

Treatment outcomes of neoadjuvant chemotherapy and transoral robotic surgery in locoregionally advanced laryngopharyngeal carcinoma.

BACKGROUND: We aimed to identify the optimal indications of neoadjuvant chemotherapy (NACT) and transoral robotic surgery (TORS) in patients with locoregionally advanced (T3-4 or N2-3) head and neck cancer (HNC). METHODS: A total of 50 patients were included in the study. RESULTS: T1 was identified in seven cases, T2 in 19, T3 in 22, and T4 in 2. N0 was identified in nine cases, N1 in 18, N2 in 22, and N3 in 1. There were 25 patients (50%) with complete remission of the primary lesion and 25 patients (50%) with partial remission. On pathologic examination of surgical specimens after neoadjuvant chemotherapy and TORS, 2 patients (4%) had a positive surgical margin, and 48 patients (96%) had a negative margin. Pathologic metastatic lymph nodes (LNs) were not observed in 39 cases (78%), and one metastatic LN was observed in 11 cases (22%). The 3-year recurrence-free survival (RFS) of all patients was 85.4%. On multivariate analysis, lymphovascular invasion showed a significant correlation with RFS. CONCLUSIONS: In patients with locoregionally advanced HNC, NACT and TORS achieved favorable oncologic and functional outcomes.

Single clonal glandular stem cells derived from human parotid glands do not attain malignant phenotype during long-term in vitro culture.

Mesenchymal stem cells (MSCs) are being intensively investigated as future therapeutics for various human diseases. One of the most important challenges to the clinical application of MSCs is the possibility of malignant transformation during long-term in vitro culturing. However, there have been no reports on the tumorigenicity of salivary gland-derived MSCs following long-term in vitro culturing. Here, we isolated a single clonal glandular stem cells from human parotid gland stem cells (hpGSCs) using a modified sub-fractionation culturing method. The possibility of malignant transformation of these cells following long-term culturing was evaluated under in vitro and in vivo culture conditions. Single clonal glandular stem cells from the human parotid gland have unique multipotent MSCs traits. hpGSCs at passage 18 stained strongly for ß-galactosidase expression and the long-term culture of hpGSCs led to a reduction in telomerase activity. hpGSCs could not survive in a soft agar environment and did not cause tumor formation in a xenograft mouse model. In addition, the expression of salivary cancer-related oncogenes was not elevated in hpGSCs following the long-term culture. In conclusion, we demonstrated that there is no possibility of acquiring a malignant transformation during long-term in vitro cell expansion of hpGSCs.

Effect of human acellular dermal matrix (Megaderm™) on infra-auricular depressed deformities, Frey's syndrome, and first bite syndrome following parotidectomy: a multi-center prospective study.

BACKGROUND: Parotidectomy is the primary treatment for parotid gland tumors. However, complications may include a prominent facial scar or infra-auricular depressed deformity, Frey's syndrome, first bite syndrome, or other facial pain, numbness, and paralysis. Acellular dermal matrix (ADM) has been widely used to prevent these complications in parotid surgery, but there have been no prospective, multi-center trials documenting its efficacy. This study evaluates the effectiveness of ADM implantation in preventing infra-auricular depressed deformity, Frey's syndrome and first bite syndrome after parotidectomy. METHODS: We analyzed 51 cases of standard parotidectomy and 58 cases of parotidectomy with implantation of Megaderm™ ADM through prospective multicenter trial. Acute complications including infection, seroma, hematoma, skin necrosis, and acute parotid area pain were evaluated 1 week postoperatively. Clinician grading of Frey's syndrome and blinded clinician evaluation of infra-auricular depressed deformities were conducted at 3, 6, and 12 months. Patients evaluated subjective satisfaction with neck appearance, Frey's syndrome quality, and acute parotid area pain at 3, 6, and 12 months. RESULTS: There was a higher incidence of seroma in the Megaderm™ group than in the control group at week 1. The incidence and total clinician-evaluated Frey's syndrome scores were significantly lower in the Megaderm™ group than in the control group at 3, 6, and 12 months. Both the objective and subjective evaluations of the facial contour showed a better outcome in the Megaderm™ group compared to the control group at 3, 6, and 12 months. There were no significant differences between the groups in the patient-reported Frey's syndrome quality scores at 3, 6, and 12 months, but the Megaderm™ group reported significantly less acute pain than the control group. CONCLUSIONS: ADM implantation can effectively reduce the occurrence of Frey's syndrome, infra-auricular depressed deformity, and first bite syndrome after parotidectomy. ADM may be especially advantageous in complex parotidectomy cases when significant complications are expected.

Alternating Unilateral Versus Bilateral Injections of Botulinum Toxin for the Treatment of Adductor Spasmodic Dysphonia.

OBJECTIVE: This study aimed to compare the long-term efficacy, durability, and dose and interval stability between alternating unilateral and bilateral injections of botulinum neurotoxin type A for the treatment of adductor spasmodic dysphonia. STUDY DESIGN: Retrospective cohort study. SETTING: Academic tertiary medical center. METHODS: A total of 137 patients (105 alternating unilateral and 32 bilateral injections) who were administered ≥5 injections of botulinum neurotoxin type A were included in this study. The mean dosage change, dose adjustment ratio (number of dose increases/total number of injections), and stability of treatment responses were compared between the alternating unilateral and bilateral injection groups. RESULTS: Long-term changes in the mean dosages for alternating unilateral (mean ± SD, -0.010 ± 0.048 IU) and bilateral (-0.042 ± 0.142 IU) injections did not differ between groups (P = .225), suggesting that both methods follow a decreasing dosing trend over time. The dose adjustment ratio also did not differ between groups (P = .077), although a longer average treatment interval (P < .001) and duration of hoarse voice (P = .045) were found in the bilateral injection group. The proportion of stable patients who did not increase injection dose and had regular follow-up did not differ between the groups. CONCLUSION: Both alternating unilateral and bilateral injection methods showed a long-term decreasing dosing trend, with comparable levels of efficacy, durability, and stability for treating adductor spasmodic dysphonia. Our findings indicate that alternating unilateral injections can be routinely performed with fewer side effects, albeit at shorter treatment intervals, than bilateral injections.

Comprehensive Analysis of Clinicopathologic Factors Predictive of an Unfavorable Prognosis in Patients With Acinic Cell Carcinoma of the Parotid Gland.

OBJECTIVES: In subset of patients, acinic cell carcinoma (AcCC) exhibits aggressive features such as recurrence, distant metastasis, and mortality. This study aimed to investigate clinicopathologic factors influencing patients' prognosis and to identify adverse features predictive of an unfavorable prognosis. METHODS: Between January 2000 and December 2016, 59 patients with AcCC were enrolled in this study. RESULTS: The patients' 5-year overall survival rate was 93.3%, and their 5-year recurrence-free survival rate was 80.5%. During the study period, recurrence occurred in 10 patients. The mean time to recurrence after surgery was 26 months (range, 5-60 months). During the study period, three patients died from the disease. Univariate analysis showed that sex, surgical extent, extranodal extension, T classification, and TNM stage were significantly associated with disease recurrence. Multivariate analysis showed that, among the clinicopathologic factors included in the analysis, only TNM stage displayed a statistically significant correlation with disease recurrence. CONCLUSION: Surgical treatment alone yielded good results for AcCC, and additional treatment did not affect the recurrence-free survival rate or the overall survival rate, even when the resection margin was less than 1 mm. Other pathologic factors did not show prognostic significance for disease recurrence or death.

Factors influencing long-term treatment response to botulinum toxin injection for spasmodic dysphonia.

OBJECTIVE: The purpose of this study was to evaluate the outcomes of long-term botulinum toxin type A (BoNTA) treatment for adductor spasmodic dysphonia (AdSD) and to determine the factors predictive of treatment response by investigating dose stability and average intervals. DESIGN: Retrospective cohort study. SETTING: Academic tertiary medical centre. EXPOSURES: A total of 470 patients with adductor spasmodic dysphonia, who received electromyography-guided BoNTA injections over 12 years, were retrospectively enrolled in this study. MAIN OUTCOMES AND MEASURES: The patients' demographic data, baseline voice dynamics and treatment profiles (dose, frequency and intervals) were evaluated. Factors correlating with the dose adjustment ratio (number of increasing dosing/total number of BoNTA toxin injections) and changes in intervals between injections were statistically analysed. RESULTS: A total of 122 patients, who received ≥ 4 injections and whose average treatment interval was < 240 days, were finally evaluated. Of them, 115 (94.3%) were female and seven (5.7%) were male, and the mean age at initial treatment was 34.89 ± 13.07 and 41.14 ± 12.71 years, respectively. On average, patients received 18.00 ± 13.33 injections (1.67 ± 0.60 U/injection) to alternating unilateral vocal folds. The treatment period was 65.07 ± 43.28 months and the mean interval between injections was 4.16 ± 1.28 months. The mean dose adjustment ratio among patients who received ≥ 4 injections was 0.15 ± 0.13, and dose changes occurred 4.36 times/patient. The patients' age and gender significantly affected the treatment response, where younger or female patients showed greater dosing variability and shorter intervals between injections. However, the baseline voice dynamics (voice handicap index, fundamental frequency, jitter, shimmer, noise-to-harmonic ratio, maximum phonation time and degree of voice breaks) did not predict the dose adjustment ratio or interval changes. In addition, patients with fluctuating doses showed lower age and higher VHI subscale scores, and patients with short-treatment interval (< 100 days) showed higher SDF0. CONCLUSIONS: Almost all patients received stable low doses of BoNTA over time, irrespective of the baseline results. Patients' age, gender and VHI scores were correlated with poor treatment responses, such as frequent dose changes and shorter intervals between injections.

Guidelines for the Management of Unilateral Vocal Fold Paralysis From the Korean Society of Laryngology, Phoniatrics and Logopedics.

The Korean Society of Laryngology, Phoniatrics and Logopedics appointed a task force to establish clinical practice guidelines for the management of unilateral vocal fold paralysis (UVFP). These guidelines cover a comprehensive range of management-related factors, including the diagnosis and treatment of UVFP, and provide in-depth information based on current, up-to-date knowledge. Detailed evidence profiles are provided for each recommendation. The CORE databases, including OVID Medline, Embase, the Cochrane Library, and KoreaMed, were searched to identify all relevant papers, using a predefined search strategy. When insufficient evidence existed, expert opinions and Delphi questionnaires were used to fill the evidence gap. The committee developed 16 evidence-based recommendations in six categories: initial evaluation (R1-4), spontaneous recovery (R5), medical treatment (R6), surgical treatment (R7-14), voice therapy (R15), and aspiration prevention (R16). The goal of these guidelines is to assist general otolaryngologists and speech-language pathologists who are primarily responsible for treating patients with UVFP. These guidelines are also intended to facilitate understanding of the condition among other health-care providers, including primary care physicians, nurses, and policy-makers.

Clinical-pathological prognostic factors and treatment failure patterns in T1-2 high-grade parotid gland cancer.

OBJECTIVES: The purpose of this study was to evaluate the treatment outcomes of patients with T1-2, high-grade parotid cancer, and to analyze the prognostic factors and treatment failure patterns. MATERIALS AND METHODS: Of the 101 patients who were diagnosed with high-grade parotid cancer from March 2003 to December 2018, a total of 39 males and 23 females who had T1-2 tumor were enrolled in this study. RESULTS: The average follow-up period of patients in this study was 63.9 months. The 5-year overall survival rate was 73.0%, and the 5-year disease-free survival rate was 57.6%. Thirty-nine patients underwent less-than-total parotidectomies, and the remaining 23 patients underwent total parotidectomies. After surgery, 50 patients received adjuvant treatment. During the study, 25 recurrences were documented, including nine local recurrences and 16 distant metastases. The average time period between the end of initial treatment and disease relapse was 17.0 months. A total of 16 patients succumbed to disease progression. Multivariate Cox proportional regression analysis showed that lymphovascular invasion (LVI) was an independent prognostic factor affecting disease recurrence and patient deaths. Among various factors, LVI and lymph node (LN) metastasis showed statistically significant correlations with distant metastasis. CONCLUSION: Although we achieved favorable therapeutic results using standard treatments in selected patients, T1-2 high-grade parotid cancers generally have poor prognosis. Distant metastases that occur during follow-up are a major factor in treatment failure and LVI and LN metastasis are significantly associated with distant metastasis.