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.

The increasing detection of papillary thyroid microcarcinoma (PTMC) has raised concerns about overtreatment.For low-risk PTMC, either immediate surgery or active surveillance (AS) can be considered. To support AS implementation, the Korean Thyroid Association convened a multidisciplinary panel and developed the first Korean guideline. AS is recommended to adults with pathologically proven Bethesda V-VI PTMC without clinical evidence of lymph node or distant metastasis, gross extrathyroidal extension, tracheal or recurrent laryngeal nerve invasion, or aggressive histology. Baseline assessment requires high‑resolution cervical ultrasound by experienced operators to rule out extrathyroidal extension, tracheal or recurrent laryngeal nerve invasion, and lymph node metastasis;contrast‑enhanced neck computed tomography is optional. Patient characteristics such as age, comorbidities, and capacity for long-term follow-up should be assessed. Shared decision-making should weigh the benefits and risks of surgery and AS, expected oncologic outcomes, complications, quality of life, anxiety, medical cost, and patient preference. Follow-up includes cervical ultrasound and thyroid function test every six months for two years, then annually. Disease progression, defined as significant tumor growth or newly detected nodal or distant metastasis, warrants surgery. Despite remaining uncertainties, this guideline offers a framework to ensure oncologic safety and support patient-centered active surveillance.

Background/Aims: Proton pump inhibitors (PPIs) play a crucial role in managing laryngopharyngeal reflux (LPR), but the optimal dosing regimen remains unclear. We aim to compare the effectiveness of the same total PPI dose administered twice daily versus once daily in LPR patients. Methods: We conducted a prospective randomized controlled trial at a tertiary referral hospital, enrolling a total of 132 patients aged 19 to 79 with LPR. These patients were randomly assigned to receive either a 10 mg twice daily (BID) or a 20 mg once daily (QD) dose of ilaprazole for 12 weeks. The Reflux Symptom Index (RSI) and Reflux Finding Score (RFS) were assessed at 8 weeks and 16 weeks. The primary endpoint was the RSI response, defined as a reduction of 50% or more in the total RSI score from baseline. We also analyzed the efficacy of the dosing regimens and the impact of dosing and duration on treatment outcomes. Results: The BID group did not display a higher response rate for RSI than the QD group. The changes in total RSI scores at the 8-week and 16-week visits showed no significant differences between the 2 groups. Total RFS alterations were also comparable between both groups.Each dosing regimen demonstrated significant decreases in RSI and RFS. Conclusions Both BID and QD PPI dosing regimens improved subjective symptom scores and objective laryngoscopic findings. There was no significant difference in RSI improvement between the 2 dosing regimens, indicating that either dosing regimen could be considered a viable treatment option.

Background/Aims: Proton pump inhibitors (PPIs) play a crucial role in managing laryngopharyngeal reflux (LPR), but the optimal dosing regimen remains unclear. We aim to compare the effectiveness of the same total PPI dose administered twice daily versus once daily in LPR patients. Methods: We conducted a prospective randomized controlled trial at a tertiary referral hospital, enrolling a total of 132 patients aged 19 to 79 with LPR. These patients were randomly assigned to receive either a 10 mg twice daily (BID) or a 20 mg once daily (QD) dose of ilaprazole for 12 weeks. The Reflux Symptom Index (RSI) and Reflux Finding Score (RFS) were assessed at 8 weeks and 16 weeks. The primary endpoint was the RSI response, defined as a reduction of 50% or more in the total RSI score from baseline. We also analyzed the efficacy of the dosing regimens and the impact of dosing and duration on treatment outcomes. Results: The BID group did not display a higher response rate for RSI than the QD group. The changes in total RSI scores at the 8-week and 16-week visits showed no significant differences between the 2 groups. Total RFS alterations were also comparable between both groups.Each dosing regimen demonstrated significant decreases in RSI and RFS. Conclusions Both BID and QD PPI dosing regimens improved subjective symptom scores and objective laryngoscopic findings. There was no significant difference in RSI improvement between the 2 dosing regimens, indicating that either dosing regimen could be considered a viable treatment option.

Background/Aims: Epidermal growth factor receptor (EGFR) mutation is important in determining the treatment strategy for advanced lung cancer patients with malignant pleural effusion (MPE). Contrary to serum carcinoembryonic antigen (S-CEA) levels, the associations between pleural fluid CEA (PF-CEA) levels and EGFR mutation status as well as between PF-CEA levels and treatment efficacy have rarely been investigated in lung adenocarcinoma patients with MPE. Methods: This retrospective study enrolled lung adenocarcinoma patients with MPE and available PF-CEA levels and EGFR mutation results. The patients were categorized based on PF-CEA levels: < 10 ng/mL, 10–100 ng/mL, 100–500 ng/mL, and ≥ 500 ng/mL. The association between PF-CEA levels and EGFR mutation status as well as their therapeutic impact on overall survival was compared among the four groups. Results: This study included 188 patients. PF-CEA level was found to be an independent predictor of EGFR mutation but not S-CEA level. The EGFR mutation rates were higher as the PF-CEA levels increased, regardless of cytology results or sample types. Among EGFR-mutant lung adenocarcinoma patients receiving EGFR-tyrosine kinase inhibitor (TKI) treatment, those with high PF-CEA levels had significantly better survival outcomes than those with low PF-CEA levels. Conclusion High PF-CEA levels were associated with high EGFR mutation rate and may lead to a favorable clinical outcome of EGFR-TKI treatment in EGFR-mutant lung adenocarcinoma patients with MPE. These findings highlight the importance of actively investigating EGFR mutation detection in patients with suspected MPE and elevated PF-CEA levels despite negative cytology results.

Background: The government of Korea implemented a strategy of prevention and early diagnosis in high-risk groups to reduce the tuberculosis (TB) burden. This study aims to investigate the TB epidemiology and gap in understanding of TB prevalence among homeless individuals by analyzing active TB chest X-ray (CXR) screening results in Korea. Methods: The Korean National Tuberculosis Association conducted active TB screening with CXR for homeless groups from January 1 to December 31, 2021. Sputum acid-fast bacilli smear and culture were performed for the subjects suggestive of TB on CXR. We performed a cross-sectional analysis of the data in comparison with the national health screening results from the general population. Results: Among 17,713 homeless persons, 40 (0.23%), 3,077 (17.37%), and 79 (0.45%) were categorized as suggested TB, inactive TB, and observation required, respectively. Prevalence of suggested TB in the homeless was significantly higher (3–5 fold) than in Univerthe national general health screening based on age category (p<0.005). Twenty-nine cases were confirmed as TB, yielding a prevalence of 164 cases per 100,000 individuals; 19 of these 29 cases showed inactive TB on CXR. Body mass index (p=0.0478) and CXR result (p<0.001) significantly correlated with confirmed TB based on multivariable analysis. Conclusion Nutrition status and CXR results, especially that of inactive TB, should be considered in active TB screening of the homeless population, where TB prevalence is higher than the general population.

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

Background/Aims: Proton pump inhibitors (PPIs) play a crucial role in managing laryngopharyngeal reflux (LPR), but the optimal dosing regimen remains unclear. We aim to compare the effectiveness of the same total PPI dose administered twice daily versus once daily in LPR patients. Methods: We conducted a prospective randomized controlled trial at a tertiary referral hospital, enrolling a total of 132 patients aged 19 to 79 with LPR. These patients were randomly assigned to receive either a 10 mg twice daily (BID) or a 20 mg once daily (QD) dose of ilaprazole for 12 weeks. The Reflux Symptom Index (RSI) and Reflux Finding Score (RFS) were assessed at 8 weeks and 16 weeks. The primary endpoint was the RSI response, defined as a reduction of 50% or more in the total RSI score from baseline. We also analyzed the efficacy of the dosing regimens and the impact of dosing and duration on treatment outcomes. Results: The BID group did not display a higher response rate for RSI than the QD group. The changes in total RSI scores at the 8-week and 16-week visits showed no significant differences between the 2 groups. Total RFS alterations were also comparable between both groups.Each dosing regimen demonstrated significant decreases in RSI and RFS. Conclusions Both BID and QD PPI dosing regimens improved subjective symptom scores and objective laryngoscopic findings. There was no significant difference in RSI improvement between the 2 dosing regimens, indicating that either dosing regimen could be considered a viable treatment option.

Background: Benign esophageal strictures are treated endoscopically, often with balloon dilatation (BD) or bougie dilators. However, recurrent esophageal strictures have been reported after BD, and severe complications sometimes occur. The aim of this study was to compare the efficacy and complications of endoscopic incisional therapy (EIT) and BD for benign esophageal strictures. Methods: We retrospectively reviewed patients who underwent BD or EIT as primary treatment for benign esophageal strictures between July 2014 and June 2021. Technical success was defined as restoration of the lumen diameter with <30% residual stenosis. Clinical success was defined as no recurrence of dysphagia within 1 month after BD or EIT and an increase of 1 grade or more on the Functional Oral Intake Scale. Results: Thirty patients with benign esophageal stricture were enrolled. There were 16 patients in the BD group and 14 patients in the EIT group. No significant differences in technical and clinical success rates were found between the two groups. Furthermore, no significant differences in the re-stricture rate were observed between the groups. There was one complication in the EIT group and three complications in the BD group. Three patients who underwent BD had re-stricture and underwent EIT thereafter, and we regrouped patients who underwent EIT at least once. The clinical success rate was significantly higher in patients regrouped to the EIT group than in patients who underwent BD only. Conclusions EIT is not inferior to BD as the primary treatment for benign esophageal strictures, especially for recurrent cases.

Objective: This study aimed to compare the mean pulse rate (PR) and mean blood pressure (BP) between patients with obstructive sleep apnea (OSA) and those with simple snoring (SS) during a 24-hour period, and to investigate the correlation between apnea-hypopnea index (AHI), PR, and BP in sleep-related breathing disorder (SRBD) patients with and without hypertension, diabetes mellitus (DM), and cardiovascular diseases (CVDs). Methods: Ninety SRBD patients underwent full-night polysomnography, and ambulatory BP and PR were monitored for 24 hours. Participants were classified into OSA (AHI ≥ 5) and control (SS) (AHI ＜ 5) groups, and BP and PR were compared. Participants were also divided into groups with and without hypertension, CVDs, or DM to analyze the correlation between AHI, BP, and PR in each group. Results: Mean PRs during the daytime period and during the whole 24-hour period in the OSA group were significantly higher than those in the SS group after controlling for potential confounders. No significant difference was observed in mean BP between the groups. Partial correlation analysis after controlling for confounders showed significant correlation between AHI and PR during daytime and the 24-hour period in participants without hypertension, DM, or CVDs, but not in participants with these conditions. Conclusion The significant differences and correlations only in PR (not in BP) found in this study suggest that PR could be an early marker for SRBD in individuals without comorbidities, and that an increased sympathetic tone could be responsible for future occurrence of CVD.