Assessment of Esophageal Reconstruction via Bioreactor Cultivation of a Synthetic Scaffold in a Canine Model

Objectives@#. Using tissue-engineered materials for esophageal reconstruction is a technically challenging task in animals that requires bioreactor training to enhance cellular reactivity. There have been many attempts at esophageal tissue engineering, but the success rate has been limited due to difficulty in initial epithelialization in the special environment of peristalsis. The purpose of this study was to evaluate the potential of an artificial esophagus that can enhance the regeneration of esophageal mucosa and muscle through the optimal combination of a double-layered polymeric scaffold and a custom-designed mesenchymal stem cell-based bioreactor system in a canine model. @*Methods@#. We fabricated a novel double-layered scaffold as a tissue-engineered esophagus using an electrospinning technique. Prior to transplantation, human-derived mesenchymal stem cells were seeded into the lumen of the scaffold, and bioreactor cultivation was performed to enhance cellular reactivity. After 3 days of cultivation using the bioreactor system, tissue-engineered artificial esophagus was transplanted into a partial esophageal defect (5×3 cm-long resection) in a canine model. @*Results@#. Scanning electron microscopy (SEM) showed that the electrospun fibers in a tubular scaffold were randomly and circumferentially located toward the inner and outer surfaces. Complete recovery of the esophageal mucosa was confirmed by endoscopic analysis and SEM. Esophagogastroduodenoscopy and computed tomography also showed that there were no signs of leakage or stricture and that there was a normal lumen with complete epithelialization. Significant regeneration of the mucosal layer was observed by keratin-5 immunostaining. Alpha-smooth muscle actin immunostaining showed significantly greater esophageal muscle regeneration at 12 months than at 6 months. @*Conclusion@#. Custom-designed bioreactor cultured electrospun polyurethane scaffolds can be a promising approach for esophageal tissue engineering.

Guideline for the Surgical Management of Locally Invasive Differentiated Thyroid Cancer From the Korean Society of Head and Neck Surgery

The aim of this study was to develop evidence-based recommendations for determining the surgical extent in patients with locally invasive differentiated thyroid cancer (DTC). Locally invasive DTC with gross extrathyroidal extension invading surrounding anatomical structures may lead to several functional deficits and poor oncological outcomes. At present, the optimal extent of surgery in locally invasive DTC remains a matter of debate, and there are no adequate guidelines. On October 8, 2021, four experts searched the PubMed, Embase, and Cochrane Library databases; the identified papers were reviewed by 39 experts in thyroid and head and neck surgery. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of evidence, and to develop and report recommendations. The strength of a recommendation reflects the confidence of a guideline panel that the desirable effects of an intervention outweigh any undesirable effects, across all patients for whom the recommendation is applicable. After completing the draft guidelines, Delphi questionnaires were completed by members of the Korean Society of Head and Neck Surgery. Twenty-seven evidence-based recommendations were made for several factors, including the preoperative workup; surgical extent of thyroidectomy; surgery for cancer invading the strap muscles, recurrent laryngeal nerve, laryngeal framework, trachea, or esophagus; and surgery for patients with central and lateral cervical lymph node involvement. Evidence-based guidelines were devised to help clinicians make safer and more efficient clinical decisions for the optimal surgical treatment of patients with locally invasive DTC.

Risk factors of postoperative hypoparathyroidism after total thyroidectomy in pediatric patients with thyroid cancer

Purpose@#Hypoparathyroidism (hypoPTH) is the most common complication following thyroidectomy. We investigated the frequency and risk factors of hypoPTH after total thyroidectomy (TT) in pediatric patients with thyroid cancer. @*Methods@#This retrospective study included 98 patients younger than 20 years who were diagnosed with thyroid cancer after T T during 1990–2018 and followed for more than 2 years at Seoul National University Hospital. HypoPTH was defined as receiving active vitamin D (1-hydroxycholecalciferol or 1,25-dihydroxycholecalciferol) after surgery. @*Results@#The study included 27 boys (27.6%) and 71 girls (72.4%). The mean age at diagnosis was 14.9±3.7 years. HypoPTH occurred in 43 patients (43.9%). Twenty-one patients (21.4%) discontinued active vitamin D less than 6 months after surgery, while 14 (14.3%) continued active vitamin D for more than 2 years. Tumor multifocality (odds ratio [OR], 3.7 vs. single tumor; P=0.013) and preoperative calcium level (OR, 0.2; P=0.028) were independent predictors of hypoPTH immediately after TT. In addition, age (OR, 0.8; P=0.011) and preoperative calcium level (OR, 0.04; P=0.014) significantly decreased the risk for persistent hypoPTH requiring active vitamin D for more than 2 years. @*Conclusion@#HypoPTH occurred in 43.9% of pediatric thyroid cancer patients after TT in this study. Among them, one-third of patients continued active vitamin D medication for more than 2 years, which was predicted by young age and low preoperative calcium level.

Clinical Practice Guidelines for Oropharyngeal Dysphagia / 대한연하장애학회지

Objective@#Dysphagia is a common clinical condition characterized by difficulty in swallowing. It is sub-classified into oropharyngeal dysphagia, which refers to problems in the mouth and pharynx, and esophageal dysphagia, which refers to problems in the esophageal body and esophagogastric junction. Dysphagia can have a significant negative impact one’s physical health and quality of life as its severity increases. Therefore, proper assessment and management of dysphagia are critical for improving swallowing function and preventing complications. Thus a guideline was developed to provide evidence-based recommendations for assessment and management in patients with dysphagia. @*Methods@#Nineteen key questions on dysphagia were developed. These questions dealt with various aspects of problems related to dysphagia, including assessment, management, and complications. A literature search for relevant articles was conducted using Pubmed, Embase, the Cochrane Library, and one domestic database of KoreaMed, until April 2021. The level of evidence and recommendation grade were established according to the Grading of Recommendation Assessment, Development and Evaluation methodology. @*Results@#Early screening and assessment of videofluoroscopic swallowing were recommended for assessing the presence of dysphagia. Therapeutic methods, such as tongue and pharyngeal muscle strengthening exercises and neuromuscular electrical stimulation with swallowing therapy, were effective in improving swallowing function and quality of life in patients with dysphagia. Nutritional intervention and an oral care program were also recommended. @*Conclusion@#This guideline presents recommendations for the assessment and management of patients with oropharyngeal dysphagia, including rehabilitative strategies.

Predictors of Early and Late Response to Esomezol and Lifestyle Modification in Adults With Laryngopharyngeal Reflux Disease: A Prospective, Multicenter, Open-Label Cohort Study

Objectives@#. This study aimed to assess predictors of the response to varying durations of proton pump inhibitor (PPI) use and lifestyle modification treatment for laryngopharyngeal reflux disease (LPRD). @*Methods@#. Between October 2014 and June 2016, a prospective, multicenter, open-label, single-cohort, intention-to-treat, observational study was conducted at eight referral hospitals across the Republic of Korea to examine predictors of early and late response to treatment in adult patients (age ≥19 years) with LPRD. Participants underwent standard treatment (PPI [Esomezol] and lifestyle modification) for 3 months. Response to treatment was defined as greater than 50% improvement in reflux symptom index score. The primary outcome was potential predictors of treatment response at 1 and 3 months. The secondary outcome was potential predictors distinguishing early from late responders. @*Results@#. In total, 394 patients were enrolled. Improved sleep habits was a positive predictor (odds ratio [OR], 1.785; 95% confidence interval [CI], 1.06–3.007; P=0.029), while initial alcohol consumption (OR, 0.587; 95% CI, 0.355–0.969; P=0.037) and past medication history (OR, 0.438; 95% CI, 0.215–0.891; P=0.005) were negative predictors of response after 1 month of treatment. High pre-reflux finding score was a positive predictor (OR, 1.187; 95% CI, 1.049– 1.344; P=0.007), while male sex (OR, 0.516; 95% CI, 0.269–0.987; P=0.046), higher depression score (OR, 0.867; 95% CI, 0.784–0.958; P=0.005), and past thyroid hormone medication history (OR, 0.161; 95% CI, 0.033–0.788; P=0.024) were negative predictors of response after 3 months of treatment. Past medication history (OR, 0.438; 95% CI, 0.215–0.891; P=0.023) was the only negative predictor for early responders compared to late responders. @*Conclusion@#. Adult patients with LPRD and a history of prior medication use may require longer treatment durations to achieve a therapeutic response. Future research should explore the incorporation of diverse treatment approaches to improve treatment outcomes for patients exhibiting negative prognostic indicators.

Standardization of FEES Evaluation for the Accurate Diagnosis of Dysphagia / 대한연하장애학회지

Objective@#Fiberoptic endoscopic evaluation of swallowing (FEES) is a standard diagnostic tool for swallowing disorders. However, it has not been used frequently in Korea because of the long test time, low cost, and the absence of a standard evaluation system. The purpose of this study was to suggest a standard fill-out form for the FEES result. @*Methods@#From February 2019 to June 2020, a total of 98 FEES tests were performed by an otolaryngologist (JYJ) at the Wonkwang University Hospital. After the exclusion of 68 cases, 30 cases were analyzed twice by 4 raters with over 5 years of experience as otolaryngologists working in various hospitals. The results were measured for the rater’s test-retest reliability and inter-rater consistency. @*Results@#Cohen’s kappa values for measuring the intra-rater consistency of the four raters were 0.984, 0.887, 0.848, and 0.930, respectively, meaning very good alignment of 0.8 or more, respectively. The Fleiss Kappa value for measuring inter-rater consistency was 0.276, meaning ‘fair’ for values of 0.2 or more. To examine consistency, an intraclass correlation coefficient (ICC) analysis conducted by assuming the grading score to be a constant continuous variable gave an ICC value of 0.729 (P＜0.001), showing a very reliable tendency. @*Conclusion@#In this study, all the items of the fill-out form were rated using a three-step grading scale, so the degree of agreement was high when performed twice by the same rater, but the degree of agreement among raters was relatively low. Therefore, our fill-out form for FEES will be useful in evaluating the improvement of a patient over the course of clinical treatment.

Hypofractionated radiotherapy for early stage glottic cancer: efficacy of 3.5 Gy per fraction

Purpose@#The purpose of this study was to evaluate the treatment outcomes and toxicity profile of patients with early glottic cancer who underwent hypofractionated radiation therapy (RT) with 3.5 Gy per fraction. @*Materials and Methods@#A retrospective review was performed of the medical records of 35 patients with early stage (T1-2N0M0) glottic cancer who underwent definitive RT. The dose fractionation scheme was 59.5 Gy in 17 fractions. Posterior commissure was excluded from the clinical target volume (CTV) for 26 patients (74.3%) without glottic lesions close to this region. @*Results@#With a median follow-up of 16.23 months (range, 6.82 to 67.15 months), no local, regional, or distant recurrence was reported. Acute hoarseness (65.7%), mucositis (68.6%), radiation dermatitis (60.0%) was frequent. One patient (2.9%) reported grade 3 acute toxicity (mucositis) and there was no grade 4–5 acute toxicity. There was no grade ≥3 late toxicities; however, grade 1 late intermittent hoarseness was frequent (45.7%). The receiver operative characteristic analysis revealed that mean hypopharyngeal dose was predictive for acute grade ≥2 mucositis (area under the curve=0.9314; 95% confidence interval, 0.8524–1). The optimal threshold of mean hypopharyngeal dose for occurrence of acute grade ≥2 mucositis was 26.31 Gy, with a specificity and sensitivity of 83.3% and 88.2%, respectively. @*Conclusion@#Hypofractionated RT with fraction size of 3.5 Gy for early glottic cancer is effective. The hypopharyngeal mean dose could predict the occurrence of grade ≥2 acute mucositis. The posterior commissure can be safely excluded from the CTV.

Aspiration Patterns Observed in Patients With Free Flap Reconstruction Following T3 and T4 Tongue and Oropharyngeal Cancer Surgery: A Fiberoptic Endoscopic Evaluation of Swallowing / 대한이비인후과학회지

Background and Objectives@#The objectives of this study were to investigate the aspiration patterns in patients with T3 and T4 oral and oropharyngeal cancers after free flap reconstruction following primary tumor resection and determine the effect of tongue base resection on aspiration patterns in these patients.Subjects and Method The aspiration pattern was evaluated via fiberoptic endoscopic evaluation of swallowing and classified into three groups based on the timing of aspiration in relation to the swallowing process. More than two types of aspiration patterns observed simultaneously in a patient suggested combined aspiration pattern. @*Results@#The major pattern of aspiration in 31 patients with oral cavity cancer was aspiration after swallowing in the group with base of tongue (BOT) preserved (83.3%, 10/12) and combined aspiration in the group with BOT resection (63.2%, 12/19), showing a significant difference in aspiration pattern between the two groups (p<0.001). In oropharyngeal malignancies, the major pattern of aspiration was aspiration after swallowing in both BOT-preserving (87.5%, 21/24) and BOT-resecting groups (75.0%, 9/12), showing a significant difference in aspiration pattern between the two groups (p=0.031). @*Conclusion@#The most common pattern observed in the advanced T stage tongue cancer patients after glossectomy was aspiration after swallowing. Resection of BOT greater than 25% in the tongue and oropharyngeal cancer was a significant factor causing the combined type of aspiration.

Transcriptomic Analysis of Papillary Thyroid Cancer: A Focus on Immune-Subtyping, Oncogenic Fusion, and Recurrence

Objectives@#. Thyroid cancer is the most common endocrine tumor, with rapidly increasing incidence worldwide. However, its transcriptomic characteristics associated with immunological signatures, driver fusions, and recurrence markers remain unclear. We aimed to investigate the transcriptomic characteristics of advanced papillary thyroid cancer. @*Methods@#. This study included 282 papillary thyroid cancer tumor samples and 155 normal samples from Chungnam National University Hospital and Seoul National University Hospital. Transcriptomic quantification was determined by high-throughput RNA sequencing. We investigated the associations of clinical parameters and molecular signatures using RNA sequencing. We validated predictive biomarkers using the Cancer Genome Atlas database. @*Results@#. Through a comparison of differentially expressed genes, gene sets, and pathways in papillary thyroid cancer compared to normal tumor-adjacent tissue, we found increased immune signaling associated with cytokines or T cells and decreased thyroid hormone synthetic pathways. In addition, patients with recurrence presented increased CD8+ T-cell and Th1-cell signatures. Interestingly, we found differentially overexpressed genes related to immune-escape signaling such as CTLA4, IDO1, LAG3, and PDCD1 in advanced papillary thyroid cancer with a low thyroid differentiation score. Fusion analysis showed that the PI3K and mitogen-activated protein kinase (MAPK) signaling pathways were regulated differently according to the RET fusion partner genes (CCDC6 or NCOA4). Finally, we identified HOXD9 as a novel molecular biomarker that predicts the recurrence of thyroid cancer in addition to known risk factors (tumor size, lymph node metastasis, and extrathyroidal extension). @*Conclusion@#. We identified a high association with immune-escape signaling in the immune-hot group with aggressive clinical characteristics among Korean thyroid cancer patients. Moreover, RET fusion differentially regulated PI3K and MAPK signaling depending on the partner gene of RET, and HOXD9 was found to be a recurrence marker for advanced papillary thyroid cancer.

Radiotherapy versus Surgery in Early-Stage HPV-Positive Oropharyngeal Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#This study aimed to compare the outcomes of primary radiotherapy (RT) versus surgery in early-stage human papilloma virus–positive oropharyngeal squamous cell carcinoma (hpv+OPC), and investigate the preoperative clinical factors that can predict the requirement for postoperative adjuvant treatment. @*Materials and Methods@#This multicenter study included 166 patients with American Joint Committee on Cancer 8th edition-Stages I-II hpv+OPC. Sixty (36.1%) and 106 (63.9%) patients underwent primary (concurrent chemo)radiotherapy [(CC)RT] and surgery, respectively. Seventy-eight patients (73.6%) in the surgery group received postoperative (CC)RT. @*Results@#With a median follow-up of 45.6 months for survivors, the 2-year overall survival (OS), progression-free survival (PFS), and locoregional control (LC) for RT/surgery were 97.8%/96.4%, 91.1%/92.0%, and 92.9%/93.3%, respectively. In multivariate analyses, patients with synchronous radiologic extranodal extension and conglomeration (ENEcong) of metastatic lymph nodes (LNs) showed significantly poorer OS (p=0.047), PFS (p=0.001), and LC (p=0.003). In patients undergoing primary surgery, two or more clinically positive LN metastases (odds ratio [OR], 5.15; p=0.004) and LN metastases with ENEcong (OR, 3.75; p=0.009) were predictors of postoperative chemoradiotherapy. No patient in the primary RT group demonstrated late severe toxicity whereas three (2.8%), one (0.9%), and one (0.9%) patient in the surgery group showed grade 3 dysphagia, grade 3 xerostomia, and fatal oral cavity bleeding. @*Conclusion@#We found no differences in OS, PFS, and LC between upfront RT and surgery in stage I-II hpv+OPC which warrants comparison through a prospective trial in the treatment de-escalation era. However, most early-stage hpv+OPC patients undergoing surgery received adjuvant (CC)RT. Pretreatment LN findings were prognostic and predictive for adjuvant treatment.

Re-irradiation for recurrent or second primary head and neck cancer

Purpose@#To investigate the efficacy and safety of intensity-modulated radiotherapy (IMRT)-based re-irradiation (reRT) for recurrent or second primary head and neck cancer (HNC). @*Materials and Methods@#Patients who underwent IMRT-based reRT for recurrent or second primary HNC between 2007 and 2019 at two institutions were included. Medical records and dosimetric data were retrospectively reviewed. Overall survival (OS), progression-free survival (PFS), severe late toxicities, and clinicopathological prognostic factors were analyzed. @*Results@#A total of 42 patients were analyzed. With a median follow-up of 15.1 months (range, 3.7 to 85.8 months), the median OS was 28.9 months with a 2-year OS rate of 54.6%. The median PFS and 2-year PFS rates were 10.0 months and 30.9%, respectively. Multivariate analysis showed that good performance (Eastern Cooperative Oncology Group [ECOG] 0 or 1), a longer time interval (≥24 months) between radiotherapy courses, and higher reRT dose (>60 Gy) were significantly favorable factors for OS (all p < 0.05). Higher reRT dose and salvage surgery were significantly associated with improved PFS (all p < 0.05). Regarding the Multi‐Institution Reirradiation (MIRI) Collaborative RPA classification, the 2-year OS rates of each class were 87.5% in class I, 51.8% in class II, and 0% in class III (p = 0.008). Grade ≥3 late toxicity was reported in 10 (23.8%) patients. There was no significant factor associated with increased late toxicities. @*Conclusion@#IMRT-based reRT should be considered as a treatment option for patients with recurrent or second primary HNC. Further trials are needed to establish a subset of patients who may benefit from reRT without severe late toxicity.

Role of concurrent chemoradiation on locally advanced unresectable adenoid cystic carcinoma

Background/Aims@#Adenoid cystic carcinoma (ACC) is a rare salivary gland tumor characterized by indolence, with a high rate of local recurrence and distant metastasis. This study aimed to investigate the effect of concurrent chemoradiation (CCRT) on locally advanced unresectable ACC. @*Methods@#We retrospectively analyzed clinical data from 10 patients with pathologically confirmed ACC of the head and neck who received CCRT with cisplatin in Seoul National University Hospital between 2013 and 2018. @*Results@#Ten patients with unresectable disease at the time of diagnosis or with positive margins after surgical resection received CCRT with weekly cisplatin. Eight patients (80%) achieved complete remission, of which three later developed distant metastases without local relapse; one patient developed distant metastasis and local relapse. Two patient achieved partial remission without progression. Patients experienced several toxicities, including dry mouth, radiation dermatitis, nausea, and salivary gland inflammation of mostly grade 1 to 2. Only one patient showed grade 3 oral mucositis. Median relapse-free survival was 34.5 months (95% confidence interval, 22.8 months to not reached). @*Conclusions@#CCRT with cisplatin is effective for local control of ACC with manageable toxicity and may be an effective treatment option for locally advanced unresectable ACC.

Tissue Engineering and Cell-Based Therapies for Dysphagia: Personal Experience of Trial & Errors / 대한연하장애학회지

Dysphagia is a significant source of patient morbidity and places a staggering economic burden on the healthcare system. Tissue engineering in the medical sciences bridge the gap left by many tissue engineering and stem cell biology titles to highlight the significance of translational research in this field in the medical sciences. It compiles basic developmental biology with a keen focus on cell and matrix biology as well as stem cells with relevance to tissue engineering biomaterials, including nanotechnology and current applications in various disciplines of medical science. In addition, it covers research ethics, laws, and industrial pitfalls that are of particular importance for the future production of tissue constructs. Tissue engineering is an interdisciplinary field of biomedical research that combines life, engineering, and materials sciences in order to improve maintenance, repair, and replacement of diseased and damaged tissues. This ever-emerging area of research applies an understanding of normal tissue physiology to develop novel biomaterial, acellular, and cell-based technologies for clinical and non- clinical applications. As evident in numerous medical disciplines, tissue engineering strategies are being increasingly developed and evaluated as potential routine therapies for oral and craniofacial tissue repair and regeneration. Here, the author present a review of the progress made in the field of regenerative medicine for the treatment of dysphagia based on the personal experience.

Development of Artificial Substitutes for Upper Digestive Tract: Personal Experience of Trials and Errors / 대한이비인후과학회지

The current treatments for esophageal diseases, such as carcinomas, trauma or congenital malformations, require surgical intervention, and esophageal reconstruction using redundant parts of the gastrointestinal tract. However, the use of gastrointestinal segments can cause various surgical morbidities and mortality because additional abdominal surgery may be required at the expense of other anatomic structures. Therefore, tissue engineering using various biomaterial or cell sources has emerged as an alternative strategy of biomimicking the native esophageal tissue that could be implanted as an artificial graft. Although tissue engineering techniques have promise as an effective regenerative strategy, no functional solution currently exists for esophageal reconstruction. Here, we present a review of the progress made in the field of regenerative medicine for esophageal reconstruction based on the personal experience.

Poor prognostic factors in human papillomavirus-positive head and neck cancer: who might not be candidates for de-escalation treatment?

BACKGROUND/AIMS@#Since patients with human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) have favorable outcomes after treatment, treatment de-escalation for these patients is being actively investigated. However, not all HPV-positive HNSCCs are curable, and some patients have a poor prognosis. The purpose of this study was to identify poor prognostic factors in patients with HPV-positive HNSCC.@*METHODS@#Patients who received a diagnosis of HNSCC and tested positive for HPV from 2000 to 2015 at a single hospital site (n = 152) were included in this retrospective analysis. HPV typing was conducted using the HPV DNA chip assay or liquid bead microarray system. Expression of p16 in the tumors was assessed by immunohistochemistry. To determine candidate factors associated with overall survival (OS), univariate and multivariable Cox regression analyses were performed.@*RESULTS@#A total of 152 patients with HPV-positive HNSCC were included in this study; 82.2% were male, 43.4% were current or former smokers, and 84.2% had oropharyngeal cancer. By univariate analysis, old age, performance status ≥ 1, non-oropharyngeal location, advanced T classification (T3–4), and HPV genotype 18 were significantly associated with poor OS. By multivariable analysis, performance status ≥ 1 and non-oropharyngeal location were independently associated with shorter OS (hazard ratio [HR], 4.36, p = 0.015; HR, 11.83, p = 0.002, respectively). Furthermore, HPV genotype 18 positivity was also an independent poor prognostic factor of OS (HR, 10.87, p < 0.001).@*CONCLUSIONS@#Non-oropharyngeal cancer, poor performance status, and HPV genotype 18 were independent poor prognostic factors in patients with HPV-positive HNSCC. Patients with these risk factors might not be candidates for de-escalation treatment.

Optimal timing for salvage surgery after definitive radiotherapy in hypopharyngeal cancer

PURPOSE: Use of radiotherapy combined with chemotherapy is increasing in hypopharyngeal cancer. However, many show residual tumor after radiotherapy. Timing for treatment evaluation and salvage therapy is essential. However, optimal timing for salvage surgery has not been suggested. In this study, we tried to evaluate optimal timing for salvage surgery. METHODS AND MATERIALS: Patients who were diagnosed with hypopharyngeal squamous cell carcinoma between 2006 and 2015 were retrospectively analyzed. All patients received definitive radiotherapy with or without chemotherapy. Response of all treated patients were analyzed at 1, 3, and 6 months after radiotherapy. Any patients with progression before 6 months were excluded. RESULTS: A total of 54 patients were analyzed. Complete remission (CR) rates at 1 month (CR1), 3 months (CR3) and 6 months (CR6) were 66.7%, 81.5%, and 90.7%, respectively. Non-CR at 1 month (NCR1), 3 months (NCR3), and 6 months (NCR6) showed poor locoregional recurrence-free survival rates (1-year rates of 63.7%, 66.7%, and 0.0%, respectively) compared to CR1, CR3, and CR6 (1-year rates 94.3%, 88.0%, and 91.5%, respectively). Particularly significant differences were seen between CR6 and NCR6 (p < 0.001). Of 10 patients with NCR3, 5 showed CR at 6 months (NCR3/CR6). There was no statistical difference in locoregional recurrence-free survival between CR3 and NCR3/CR6 group (p = 0.990). CONCLUSION: Our data suggest half of patients who did not show CR at 3 months eventually achieved CR at 6 months. Waiting until 6 months after radiotherapy may be appropriate for avoiding additional salvage therapy.

Corrigendum: Study Protocol of Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro)

No abstract available.

Efficacy of Calcium Hydroxyapatite in Vocal Fold Augmentation for Unilateral Vocal Fold Paralysis in Asian

BACKGROUND AND OBJECTIVES: This study aimed to evaluate efficacy and complication of injection laryngoplasty using calcium hydroxyapatite (CaHA) for unilateral vocal fold paralysis in Asian. MATERIALS AND METHODS: A prospective study was conducted on the adult patients with unilateral vocal fold paralysis from May 2015 through January 2016. Injection laryngoplasty was performed by one laryngologist. All patients underwent prospective voice evaluation using the subjective and objective comprehensive battery of assessments, before the procedure and after the procedure at 3 months, and 6 months. RESULTS: A total of 7 patients (5 males and 2 females) were included in this study. VHI-10 was significantly decreased after injection laryngoplasty, at postoperative 6 months (p=0.031), while VAS score and MDADI showed no difference. GRBAS scale gradually decreased in 3 months and 6 months follow-up without statistical significance. Acoustic analysis revealed that jitter, shimmer, and noise-to-harmonic ratio continuously decreased from the baseline at 3 months and 6 months, although statistical significance was not attained. In the aerodynamic analysis, maximal phonation time was gradually increased at 3months and 6 months with significant difference (p=0.016, 0.031, respectively). There was no side effect associated with the procedure. CONCLUSION: CaHA can be safely used in Asian patients and the onset of maximal efficacy seems to be slow than other studies with Caucasian patients.

Serial Analysis of Tracheal Restenosis After 3D-Printed Scaffold Implantation: Recruited Inflammatory Cells and Associated Tissue Changes

Tracheal restenosis is a major obstacle to successful tracheal replacement, and remains the greatest challenge in tracheal regeneration. However, there have been no detailed investigations of restenosis. The present study was performed to analyze the serial changes in recruited inflammatory cells and associated histological changes after tracheal scaffold implantation. Asymmetrically porous scaffolds, which successfully prevented tracheal stenosis in a partial trachea defect model, designed with a tubular shape by electrospinning and reinforced by 3D-printing to reconstruct 2-cm circumferential tracheal defect. Serial rigid bronchoscopy, micro-computed tomography, and histology [H&E, Masson's Trichrome, IHC against a-smooth muscle actin (α-SMA)] were performed 1, 4, and 8 weeks after transplantation. Progressive stenosis developed especially at the site of anastomosis. Neutrophils were the main inflammatory cells recruited in the early stage, while macrophage infiltration increased with time. Recruitment of fibroblasts peaked at 4 weeks and deposition of a-SMA increased from 4 weeks and was maintained through 8 weeks. During the first 8 weeks post-transplantation, neutrophils and macrophages played significant roles in restenosis of the trachea. Antagonists to these would be ideal targets to reduce restenosis and thus play a pivotal role in successful tracheal regeneration.

Exploratory Study on Guide Wire-Guided Tongue Resection under Ultrasonography for Adequate Safe Margins in Tongue Cancer Surgery / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The adequate safety margin in tongue cancer is the most important prognostic factor for local recurrence and survival. This study aimed to evaluate the resection margins using a new technique of tongue resection under the guidance of guide wire under ultrasonography in patients with tongue cancer. SUBJECTS AND METHOD: In this prospective study, 10 patients with presurgical, biopsy-proven, clinical T1 or T2 tongue squamous cell carcinomas underwent resection under the guidance of guide wire inserted using ultrasonography. The data of resection margins of 37 patients who underwent partial glossectomy using the conventional method of palpation were used as control data. RESULTS: The mean safety margins (mm) of the experimental group were 7.59±4.30 (anterior), 8.56±4.69 (posterior), 5.25±3.01 (superior), 5.93±3.66 (inferior), 13.00±13.29 (medial), 5.78±2.64 (deep), and 6.67±3.06 (lateral). There were no differences in the safety margins between the two groups. CONCLUSION: Using guide wire under ultrasonography was not superior to the conventional method for partial glossectomy for having adequate resection margins.