Purpose: Recurrent laryngeal nerve injury after thyroid surgery may cause vocal cord palsy (VCP), which leads to unexpected additional costs. In recent years, intraoperative neural monitoring (IONM) has been used to lower the incidence rate of VCP. This study aimed to analyze postoperative management costs for patients with papillary thyroid carcinoma (PTC). Methods: We analyzed the medical records of patients who underwent lobectomy for PTC from September 2018 to August 2019 at The Catholic University of Korea, Seoul St. Mary’s Hospital. A total of 411 patients were enrolled and all the patients had voice examinations. We investigated the total costs in the IONM and non-IONM groups during a maximum 1-year follow-up and calculated the additional costs due to VCP by subtraction of the mean values in each group. Results: The incidence rate of VCP was 3.9% (16 of 411). Extrathyroidal extension was related to VCP in Cox regression tests and accounted for 3.2% (13 of 411). VCP rate did not show a significant difference between the IONM and non-IONM groups (4.1% vs. 3.8%, P = 0.883). Total costs for postoperative management were higher in the IONM group than in the non-IONM group (US $328.2 ± $220.1 vs. $278.7 ± $141.4, P < 0.05). However, the additional costs due to VCP were significantly lower in the IONM group than in the non-IONM group ($474.1 ± $150.3 vs. $568.9 ± $367.6, P < 0.005). Conclusion The use of IONM can mitigate the increase in costs by saving additional expenses associated with VCP.

Background: There is debate about ultrasonography screening for thyroid cancer and its cost-effectiveness. This study aimed to evaluate the cost-effectiveness of early screening (ES) versus symptomatic detection (SD) for differentiated thyroid cancer (DTC) in Korea. Methods: A Markov decision analysis model was constructed to compare the cost-effectiveness of ES and SD. The model considered direct medical costs, health outcomes, and different diagnostic and treatment pathways. Input data were derived from literature and Korean population studies. Incremental cost-effectiveness ratio (ICER) was calculated. Willingness-to-pay (WTP) threshold was set at USD 100,000 or 20,000 per quality-adjusted life year (QALY) gained. Sensitivity analyses were conducted to address uncertainties of the model’s variables. Results: In a base case scenario with 50 years of follow-up, ES was found to be cost-effective compared to SD, with an ICER of $2,852 per QALY. With WTP set at $100,000, in the case with follow-up less than 10 years, the SD was cost-effective. Sensitivity analysis showed that variables such as lobectomy probability, age, mortality, and utility scores significantly influenced the ICER. Despite variations in costs and other factors, all ICER values remained below the WTP threshold. Conclusion Findings of this study indicate that ES is a cost-effective strategy for DTC screening in the Korean medical system. Early detection and subsequent lobectomy contribute to the cost-effectiveness of ES, while SD at an advanced stage makes ES more cost-effective. Expected follow-up duration should be considered to determine an optimal strategy for DTC screening.

Background and Objectives: Protein-losing enteropathy (PLE) is a devastating complication after the Fontan operation. This study aimed to investigate the clinical characteristics, treatment response, and outcomes of Fontan-associated PLE. Methods: We reviewed the medical records of 38 patients with Fontan-associated PLE from 1992 to 2018 in 2 institutions in Korea. Results: PLE occurred in 4.6% of the total 832 patients after the Fontan operation. After a mean period of 7.7 years after Fontan operation, PLE was diagnosed at a mean age of 11.6years. The mean follow-up period was 8.9 years. The survival rates were 81.6% at 5 years and 76.5% at 10 years. In the multivariate analysis, New York Heart Association Functional classification III or IV (p=0.002), low aortic oxygen saturation (<90%) (p=0.003), and ventricular dysfunction (p=0.032) at the time of PLE diagnosis were found as predictors of mortality. PLE was resolved in 10 of the 38 patients after treatment. Among medical managements, an initial heparin response was associated with survival (p=0.043). Heparin treatment resulted in resolution in 4 patients. We found no evidence on pulmonary vasodilator therapy alone. PLE was also resolved after surgical Fontan fenestration (2/6), aortopulmonary collateral ligation (1/1), and transplantation (1/1). Conclusions The survival rate of patients with Fontan-associated PLE has improved with the advancement of conservative care. Although there is no definitive method, some treatments led to the resolution of PLE in one-fourth of the patients. Further investigations are needed to develop the best prevention and therapeutic strategies for PLE.

Background: We aim to validate the diagnostic performance of thyroid core needle biopsy (CNB) for diagnosing malignancy in clinical settings to align with the changes made in recently updated thyroid CNB guidelines. Methods: We retrospectively analyzed 1,381 thyroid CNB and 2,223 fine needle aspiration (FNA) samples. The FNA and CNB slides were interpreted according to the Bethesda System for Reporting Thyroid Cytopathology and updated practice guidelines for thyroid CNB, respectively. Results: Compared to FNA, CNB showed lower rates of inconclusive results: categories I (2.8% vs. 11.2%) and III (1.2% vs. 6.2%), and higher rates of categories II (60.9% vs. 50.4%) and IV (17.5% vs. 2.0%). The upper and lower bounds of the risk of malignancy (ROM) for category IV of CNB were 43.2% and 26.6%, respectively. The CNB subcategory IVb with nuclear atypia had a higher ROM than the subcategory without nuclear atypia (40%–62% vs. 23%–36%). In histologically confirmed cases, there was no significant difference in the diagnostic performance between CNB and FNA for malignancy. However, neoplastic diseases were more frequently detected by CNB than by FNA (88.8% vs. 77.6%, P=0.046). In category IV, there was no difference in unnecessary surgery rate between CNB and FNA (4.7% vs. 6.9%, P=0.6361). Conclusion Thyroid CNB decreased the rate of inconclusive results and showed a higher category IV diagnostic rate than FNA. The revised guidelines for thyroid CNB proved to be an excellent reporting system for assessing thyroid nodules.

Background: This systematic review was conducted to identify and summarize key factors, including economic methods, topics, results, and indicators, within relevant economic evaluation research on thyroid cancer. Materials and Methods: A literature search on the economic evaluation of thyroid cancer treatment was conducted using the MEDLINE database up to May 2021. Data on population, intervention, comparison, outcome, time, setting, and study design were extracted from each study. The economic evaluation method in each study was re-classified according to the theoretical criteria defined by the international economic evaluation guidelines. Results: A total of 49 studies were included, involving cost analysis (CA, n=9), cost-minimization analysis (CMA, n=3), cost-effectiveness analysis (CEA, n=29), and cost-utility analysis (CUA, n=8). When CEA and CUA were classified as one method, the consistency between the methods of the reviewers based on the theoretical criteria and those from the original studies was 77% (95% confidence interval, 0.63-0.92). Most studies dealt with specific period-related controversial issues including comparison between treatment strategies, and cost-effectiveness of the prophylactic central neck dissection, molecular testing, and rhTSH. Contrasting results have been obtained when different economic evaluation methods were applied for the same topic (e.g., total thyroidectomy [TT] was more dominant than hemithyroidectomy [HT] in CEA, but HT was more dominant than TT in CUA), and different clinical and economic inputs were applied. All studies included direct medical costs, which were mostly derived from Medicare and input probabilities in each economic model, and utility scores for outcomes were mostly based on literature reviews.Few studies included non-medical direct costs and indirect costs. Conclusion Our systematic review provides information on how to design and proceed to overcome the limitations of existing studies and ensure validity.

Background: Postoperative thyroid stimulating hormone (TSH) suppression therapy is recommended for patients with intermediate- and high-risk differentiated thyroid cancer to prevent the recurrence of thyroid cancer. With the recent increase in small thyroid cancer cases, the extent of resection during surgery has generally decreased. Therefore, questions have been raised about the efficacy and long-term side effects of TSH suppression therapy in patients who have undergone a lobectomy. Methods: This is a multicenter, prospective, randomized, controlled clinical trial in which 2,986 patients with papillary thyroid cancer are randomized into a high-TSH group (intervention) and a low-TSH group (control) after having undergone a lobectomy. The principle of treatment includes a TSH-lowering regimen aimed at TSH levels between 0.3 and 1.99 μIU/mL in the low-TSH group. The high-TSH group targets TSH levels between 2.0 and 7.99 μIU/mL. The dose of levothyroxine will be adjusted at each visit to maintain the target TSH level. The primary outcome is recurrence-free survival, as assessed by neck ultrasound every 6 to 12 months. Secondary endpoints include disease-free survival, overall survival, success rate in reaching the TSH target range, the proportion of patients with major cardiovascular diseases or bone metabolic disease, the quality of life, and medical costs. The follow-up period is 5 years. Conclusion The results of this trial will contribute to establishing the optimal indication for TSH suppression therapy in low-risk papillary thyroid cancer patients by evaluating the benefit and harm of lowering TSH levels in terms of recurrence, metabolic complications, costs, and quality of life.

Background and Objectives: Fine needle aspiration cytology (FNAC) combined with washout thyroglobulin (Tg) measurement is the gold standard for the evaluation of metastatic lymph nodes (LNs) in thyroid cancer. However, few studies have assessed the clinical outcomes of discordant results between FNAC and washout Tg based on surgery status and follow-up imaging in real-world practice. Materials and Methods: A total of 707 LNs in 512 patients who underwent FNAC and washout Tg measurements from 2015 to 2017 were analyzed. The final LN outcomes were confirmed through postoperative histology, or through metastatic FNAC findings combined with high washout Tg level, follow-up imaging studies, or repeat FNA, if LNs were not dissected. Results: The cut-off values of washout Tg for indicating LN metastasis in preoperative and postoperative LNs were 9.6 ng/mL and 2.1 ng/mL. The diagnostic accuracy was improved by applying washout Tg according to surgery status and the results of discordant rate was reduced, Discordant between results of FNAC with washout Tg and final outcome were 9.2% (27/295) of preoperative LNs and 8.7% (36/412) of postoperative LNs. Due to inconclusive results, unnecessary neck dissection can occur in 13.9% (36/259 dissected cases). Conclusion To improve diagnostic accuracy, cut-off values of washout Tg should be applied depending on surgery status. New biomarkers in washout fluid is necessary to resolve discordant findings.

Background: Postoperative thyroid stimulating hormone (TSH) suppression therapy is recommended for patients with intermediate- and high-risk differentiated thyroid cancer to prevent the recurrence of thyroid cancer. With the recent increase in small thyroid cancer cases, the extent of resection during surgery has generally decreased. Therefore, questions have been raised about the efficacy and long-term side effects of TSH suppression therapy in patients who have undergone a lobectomy. Methods: This is a multicenter, prospective, randomized, controlled clinical trial in which 2,986 patients with papillary thyroid cancer are randomized into a high-TSH group (intervention) and a low-TSH group (control) after having undergone a lobectomy. The principle of treatment includes a TSH-lowering regimen aimed at TSH levels between 0.3 and 1.99 μIU/mL in the low-TSH group. The high-TSH group targets TSH levels between 2.0 and 7.99 μIU/mL. The dose of levothyroxine will be adjusted at each visit to maintain the target TSH level. The primary outcome is recurrence-free survival, as assessed by neck ultrasound every 6 to 12 months. Secondary endpoints include disease-free survival, overall survival, success rate in reaching the TSH target range, the proportion of patients with major cardiovascular diseases or bone metabolic disease, the quality of life, and medical costs. The follow-up period is 5 years. Conclusion The results of this trial will contribute to establishing the optimal indication for TSH suppression therapy in low-risk papillary thyroid cancer patients by evaluating the benefit and harm of lowering TSH levels in terms of recurrence, metabolic complications, costs, and quality of life.

Background and Objectives: Fine needle aspiration cytology (FNAC) combined with washout thyroglobulin (Tg) measurement is the gold standard for the evaluation of metastatic lymph nodes (LNs) in thyroid cancer. However, few studies have assessed the clinical outcomes of discordant results between FNAC and washout Tg based on surgery status and follow-up imaging in real-world practice. Materials and Methods: A total of 707 LNs in 512 patients who underwent FNAC and washout Tg measurements from 2015 to 2017 were analyzed. The final LN outcomes were confirmed through postoperative histology, or through metastatic FNAC findings combined with high washout Tg level, follow-up imaging studies, or repeat FNA, if LNs were not dissected. Results: The cut-off values of washout Tg for indicating LN metastasis in preoperative and postoperative LNs were 9.6 ng/mL and 2.1 ng/mL. The diagnostic accuracy was improved by applying washout Tg according to surgery status and the results of discordant rate was reduced, Discordant between results of FNAC with washout Tg and final outcome were 9.2% (27/295) of preoperative LNs and 8.7% (36/412) of postoperative LNs. Due to inconclusive results, unnecessary neck dissection can occur in 13.9% (36/259 dissected cases). Conclusion To improve diagnostic accuracy, cut-off values of washout Tg should be applied depending on surgery status. New biomarkers in washout fluid is necessary to resolve discordant findings.