Objectives: . Differentiated thyroid cancer (DTC) has a favorable prognosis. However, indeterminate lymph nodes (LNs) are common, making it challenging to distinguish recurrent from persistent DTC. Previous studies have not specifically compared the prognosis between recurrent and persistent DTC. Therefore, we aimed to compare prognosis and oncologic characteristics between these two groups. Methods: . This retrospective cohort study was conducted at a single tertiary care institution and included 265 patients with DTC (recurrent, 109; persistent, 156) who underwent reoperation between November 1, 1999, and August 31, 2018, for structural disease. Patients with distant metastasis at the time of initial diagnosis were excluded. Clinical and oncological characteristics, patterns of LN metastasis, disease-free survival (DFS), and overall survival (OS) were compared between the two groups. For DFS, time zero was defined as the date of the second operation. Results: . Recurrent DTC had a higher incidence of central LN metastasis (P=0.003), infield recurrence (P<0.001), and distant metastasis (P<0.001). In contrast, persistent DTC more frequently exhibited lateral LN metastasis (P=0.003) and outfield recurrence (P<0.001). The most common site of neck LN metastasis was ipsilateral level VI/VII (51.4%) in recurrent DTC and ipsilateral level IV (43.0%) in persistent DTC. Ten-year DFS was significantly lower in recurrent DTC than in persistent DTC (41.0% vs. 67.9%; P<0.001). Recurrent DTC, older age, a higher number of metastatic LNs at the second operation (first reoperation), and R1/R2 resection at the second operation were associated with decreased DFS. OS did not significantly differ between recurrent and persistent DTC (P=0.160). Conclusion . Recurrent DTC is associated with poorer DFS than persistent DTC, although OS does not significantly differ between the two groups.

Background/Aims: The absence of standardized clinical minimum inhibitory concentration (MIC) breakpoints for Helicobacter pylori infection has resulted in inconsistent resistance definitions, even within the same research group in Korea. Therefore, establishing epidemiological cutoff values (ECOFFs) is essential for standardization. Methods: The MIC distributions for antibiotics commonly used against H. pylori infection in South Korea were analyzed from 2015 to 2023. A total of 5,925 primary H. pylori isolates were collected from five data sources, and MIC values were determined using the serial 2-fold agar dilution method. The ECOFFinder program was used to establish ECOFFs for six antibiotics. Results: The tentative ECOFFs for amoxicillin and clarithromycin were 0.125 μg/mL. The ECOFFs for levofloxacin, metronidazole, and tetracycline were 0.5, 8.0, and 0.25 μg/mL, respec-tively. The ECOFF for rifabutin could not be determined due to insufficient data. On the basis of these ECOFFs, the resistance rate was 17.9% for amoxicillin, 31.9% for clarithromycin, 40.9% for levofloxacin, 24.7% for metronidazole, and 11.5% for tetracycline. Conclusions This comprehensive analysis defined regional antibiotic resistance patterns and established Korea-specific ECOFFs, providing a foundation for determining clinical breakpoints and optimizing H. pylori eradication strategies.

In patients with differentiated thyroid cancer (DTC), initial recurrence risk stratification based on clinical, histopathological, and perioperative data remains the key determinant for guiding management strategies during the first 1-2 years post-treatment. However, the adoption of ongoing risk stratification (ORS), which dynamically reassesses risk by integrating longitudinal clinical data and treatment response, enables more precise long-term prognostic assessment and facilitates highly individualized management. Building upon recent guidelines, the 2026 KTA guideline has been further refined by incorporating robust evidence from large-scale national cohorts and comprehensive systematic reviews. These updated recommendations outline contemporary concepts of ORS, risk-adapted TSH suppression targets, optimized surveillance modalities for recurrence detection, and disease-specific long-term follow-up strategies. Reflecting the paradigm shift toward de-escalated treatment, this revision integrates evolved perspectives on TSH suppression intensity, the clinical interpretation of thyroglobulin levels, and tailored follow-up intervals. These evidence-based recommendations aim to minimize unnecessary treatment and excessive surveillance in the large proportion of patients with excellent prognosis after initial therapy, while ensuring that each patient receives appropriately tailored and effective long-term management.

Although many wearable devices are used to assess sleep, their accuracy remains controversial. This study aimed to investigate the accuracy of the Actiwatch, a research-grade device, and the Fitbit, a consumer-grade device, against sleep diaries to assess sleep patterns. Methods: Twenty participants wore Fitbit and Actiwatch for two weeks and tracked their sleep patterns using sleep diaries. Total sleep time (TST), time-in-bed (TIB), sleep efficiency (SE), sleep onset latency (SOL), and wake after sleep onset (WASO) from the two devices and sleep diaries were analyzed using analysis of variance and Bland-Altman analysis. Results: The TIB measured by the sleep log, Fitbit, and Actiwatch were 420.9 minutes, 417.3 minutes, and 567.4 minutes, respectively. Compared to the sleep log, the Fitbit underestimated TST, TIB, and SE, with significant differences observed for TST (p<0.001) and SE (p<0.001), but not for TIB. The Actiwatch overestimated TIB (p<0.001) and TST (p=0.02) and underestimated SE (p<0.001) compared to the sleep log. The difference between the Fitbit and Actiwatch was significant for TST, TIB, and SE (all p<0.001). Conclusions: The Fitbit showed a smaller difference than the Actiwatch when compared with the sleep logs. The Fitbit could be used as a tool to assess sleep patterns in the clinic as well as in daily life.

Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.

Objective: We aimed to determine whether individuals at immediate risk of suicide could be identified using data from a commercially available wearable device. Methods: Thirty-nine participants experiencing acute depressive episodes and 20 age- and sex-matched healthy controls wore a commercially available wearable device (Galaxy Watch Active2) for two months. We collected data on activities, sleep, and physiological metrics like heart rate and heart rate variability using the wearable device. Participants rated their mood spontaneously twice daily on a Likert scale displayed on the device. Mood ratings by clinicians were performed at weeks 0, 2, 4, and 8. The suicide risk was assessed using the Hamilton Depression Rating Scale’s suicide item score (HAMD-3). We developed two predictive models using machine learning: a single-level model that processed all data simultaneously to identify those at immediate suicide risk (HAMD-3 scores ≥1) and a multilevel model. We compared the predictions of imminent suicide risk from both models. Results: Both the single-step and multi-step models effectively predicted imminent suicide risk. The multi-step model outperformed the single-step model in predicting imminent suicide risk with area under the curve scores of 0.89 compared to 0.88. In the multi-step model, the HAMD total score and heart rate variability were most significant, whereas in the single-step model, the HAMD total score and diagnosis were key predictors. Conclusion Wearable devices are a promising tool for identifying individuals at immediate risk of suicide. Future research with more refined temporal resolution is recommended.

Purpose: To investigate the association between soluble suppressor of tumorigenicity 2 (sST2) levels and cardiovascular disease predictors in patients with gout. Materials and Methods: We retrospectively reviewed the medical records of patients with gout who were tested for sST2 but did not receive uric acid-lowering therapy. These patients were classified into elevated and normal sST2 groups using a cut-off of >49.6 ng/mL and >35.4 ng/mL in males and females, respectively. Correlations between clinical and laboratory variables, sST2 levels, and elevated sST2 level predictors were assessed using linear and logistic regression analyses. Results: Notably, 27 (11.3%) and 211 (88.7%) of the 238 identified patients had elevated and normal sST2 levels, respectively. Linear regression analysis revealed that male sex (β=-0.190, p=0.002), body mass index (BMI) (β=-0.184, p=0.002), white blood cell count (β=0.231, p<0.001), C-reactive protein (β=0.135, p=0.031), and fasting blood glucose (β=0.210, p<0.001) were independently associated with sST2 levels. In multivariate logistic regression analysis, male sex [odds ratio (OR) 0.112, p=0.001], BMI (OR 0.836, p=0.008), creatinine (OR 5.730, p=0.024), and fasting blood glucose (OR 1.042, p=0.002) predicted elevated sST2 levels. Patients with increased sST2 levels had a significantly higher atherosclerotic cardiovascular disease risk score and a greater proportion of high-risk Framingham Risk Score compared to the normal sST2 group (p=0.002 and p<0.001). Conclusion Patients with gout and elevated sST2 levels have a higher risk of future cardiovascular disorders, which may provide insights into risk stratification and the implementation of intervention strategies.

Purpose: This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer. Materials and Methods: A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery. Results: Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064). Conclusions Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.