Coronary CT-derived fractional flow reserve (CT-FFR) is a noninvasive alternative to invasive FFR for assessing the hemodynamic significance of coronary artery stenosis. CT-FFR uses routinely acquired coronary CT angiography (CCTA) with artificial intelligence and computational fluid dynamics to estimate pressure gradients, thereby supporting clinical decisionmaking without procedural risk. Adoption and implementation vary widely across regions. In Asia, South Korea exclusively uses HeartMedi+, which enables rapid analysis, streamlined workflow integration, and high user satisfaction. Japan relies primarily on FFR CT, which has national reimbursement and significantly influences treatment strategies, reducing unnecessary invasive procedures. Hong Kong, Singapore, Taiwan, Thailand, and Vietnam remain in early or exploratory phases due to cost, reimbursement, and infrastructure barriers. In the United States, CT-FFR is guideline-endorsed and reimbursed, where HeartFlow is the most widely used, supported by robust clinical validation and outcome data. Despite regional variability, CTFFR offers a noninvasive solution that enhances patient management, reduces unnecessary invasive testing, and is poised for broader clinical integration as technology and validation advance.

Subglottic stenosis (SGS) and tracheal stenosis (TS) are rare conditions that can cause significant breathing difficulties and, if not properly managed, may lead to life-threatening complications. Despite their clinical importance, debate continues regarding the optimal management of adult SGS and TS, and no comprehensive guidelines have been established to date. The Korean Bronchoesophagological Society appointed a task force to develop clinical practice guidelines with the goal of providing evidence-based recommendations for managing SGS and TS in adults. The task force conducted a systematic review of the relevant literature by searching PubMed, Embase, and the Cochrane Library using predefined search terms aligned with key clinical questions. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach, which also informed the formulation and reporting of the recommendations. The strength of each recommendation reflects the guideline panel’s confidence that the benefits of an intervention outweigh its risks for eligible patients. After drafting the guidelines, feedback was obtained through Delphi questionnaires completed by members of the Korean Bronchoesophagological Society. Ultimately, the committee developed 17 evidence-based recommendations across four categories: initial evaluation, medical management, surgical treatment, and postoperative management and rehabilitation. These guidelines aim to support clinicians in delivering optimal care to adult patients with SGS and TS.

Purpose: Radiotherapy (RT) remains a cornerstone of curative treatment for localized and locally advanced prostate cancer. However, dose escalation to improve tumor control is often constrained by the proximity of the rectum, which increases the risk of gastrointestinal (GI) and genitourinary toxicities. Biodegradable rectal spacers inserted between the prostate and rectum have emerged as an effective approach to reduce rectal radiation exposure. This guideline provides evidence-based recommendations on indications, contraindications, procedural standards, and clinical management for biodegradable rectal spacer insertion during prostate cancer RT. Materials and Methods: This guideline was developed by a multidisciplinary expert panel through a systematic review of the literature, analysis of international guidelines (National Comprehensive Cancer Network, European Association of Urology, American Society for Radiation Oncology), and expert consensus among radiation oncologists, radiologists, and urologists with clinical experience in spacer insertion. The strength of each recommendation and the level of evidence were classified according to the modified GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Results: Spacer insertion is conditionally recommended (Grade C, Level I) for patients receiving definitive external-beam RT without rectal invasion. It reduces the high-dose rectal irradiation volume (V70–75) by >50%, decreases acute GI toxicity, and helps maintain bowel-related quality of life. However, the benefit for late severe toxicity (grade 2 or higher) remains debated in recent meta-analyses. Contraindications include rectal invasion, anatomical inaccessibility, infection, and material hypersensitivity. Procedures should be performed under local anesthesia in a sterile environment by trained physicians. Short-course antibiotics and simulator-based training, including completion of multiple supervised cases, are advised. Conclusion Biodegradable rectal spacer insertion is clinically validated and effective in reducing acute rectal toxicity. Although pivotal trials demonstrated a favorable procedural safety profile, real-world postmarket data include reports of rare but severe procedural complications. This guideline provides standardized recommendations tailored to Korean clinical practice while remaining consistent with international standards, emphasizing the importance of operator training and careful patient selection.

Objective: To classify life stages for companion dogs and cats by identifying clusters in age-specific disease proportions derived from medical records, providing a data-driven foundation for health examination programs. Methods: We collected 505,667 medical records from 82 veterinary facilities in South Korea between 2020 and 2023. Diagnoses were standardized using GPT-4o and S-BioBERT. Following preprocessing, data from 27 facilities yielded 222,706 canine and 39,910 feline records for the final analysis. Principal component analysis and K-means clustering (K = 4) were applied to age-specific disease proportions to identify life stages.The 10 most highest-proportion diagnoses diseases were determined for each cluster. Results: Canine life stages were classified as ≤ 1 year, 2–5 years, 6–10 years, and 11–15+ years.Feline life stages were 1–2 years, 3–8 years, 9–12 years, and 13–15+ years. In dogs, developmental diseases were common in the youngest age group, while chronic diseases were more prevalent in older groups. In cats, oral and urinary diseases were high-ranking, conjunctivitis was most common in the early stage, and chronic diseases increased with age. Conclusions and Relevance: Age-specific diagnosis patterns support four practical life stages for dogs and cats in South Korea. These boundaries can inform evidence-based preventive examination schedules, animal health policy, and pet insurance product design.

Purpose: To evaluate the characteristics, anatomical success rate, and factors that may affect the anatomical success of rhegmatogenous retinal detachment in patients in their 20s. Methods: We retrospectively analyzed the medical records of patients aged 20-29 years who underwent surgery for rhegmatogenous retinal detachment from January 2018 to December 2022. We examined factors such as sex, age, duration of illness, preoperative best corrected visual acuity, presence of underlying diseases, proliferative vitreoretinopathy, lattice degeneration, macular involvement, extent of retinal detachment at diagnosis, axial length, and myopia level to explore their impact on surgical outcomes. Results: The study included 122 eyes. The mean age was 23.81 ± 2.82 years, and the average sphere power was -5.80 ± 3.71 diopters (D). The percentage of eyes with a refraction of ≤ -6.0 D came to 44.3% (54/122), and with ≤ -4.0 D it amounted to 72.1% (88/122). The average logarithm of the minimum angle of resolution (logMAR) best corrected visual acuity improved significantly from 0.52 ± 0.68 before surgery to 0.28 ± 0.45 after surgery. The primary surgical success rates were 92.0% for scleral buckling, 88.9% for vitrectomy, and 92.3% for combined scleral buckling and vitrectomy, with no significant factors related to anatomical success identified. Conclusions There was a high prevalence of moderate to severe myopia among patients in their 20s with rhegmatogenous retinal detachment. However, no statistically significant correlation was found between the degree of myopia and anatomical success. Both functional and anatomical outcomes were generally favorable in these patients.

Purpose: To evaluate the characteristics, anatomical success rate, and factors that may affect the anatomical success of rhegmatogenous retinal detachment in patients in their 20s. Methods: We retrospectively analyzed the medical records of patients aged 20-29 years who underwent surgery for rhegmatogenous retinal detachment from January 2018 to December 2022. We examined factors such as sex, age, duration of illness, preoperative best corrected visual acuity, presence of underlying diseases, proliferative vitreoretinopathy, lattice degeneration, macular involvement, extent of retinal detachment at diagnosis, axial length, and myopia level to explore their impact on surgical outcomes. Results: The study included 122 eyes. The mean age was 23.81 ± 2.82 years, and the average sphere power was -5.80 ± 3.71 diopters (D). The percentage of eyes with a refraction of ≤ -6.0 D came to 44.3% (54/122), and with ≤ -4.0 D it amounted to 72.1% (88/122). The average logarithm of the minimum angle of resolution (logMAR) best corrected visual acuity improved significantly from 0.52 ± 0.68 before surgery to 0.28 ± 0.45 after surgery. The primary surgical success rates were 92.0% for scleral buckling, 88.9% for vitrectomy, and 92.3% for combined scleral buckling and vitrectomy, with no significant factors related to anatomical success identified. Conclusions There was a high prevalence of moderate to severe myopia among patients in their 20s with rhegmatogenous retinal detachment. However, no statistically significant correlation was found between the degree of myopia and anatomical success. Both functional and anatomical outcomes were generally favorable in these patients.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background/Aims: This study aimed to evaluate the performance of the Model for End-Stage Liver Disease (MELD) 3.0 for predicting mortality and liver-related complications compared with the Child-Pugh classification, albumin-bilirubin (ALBI) grade, the MELD, and the MELD sodium (MELDNa) score. Methods: We evaluated a multicenter retrospective cohort of incorporated patients with cirrhosis between 2013 and 2019. We conducted comparisons of the area under the receiver operating characteristic curve (AUROC) of the MELD3.0 and other models for predicting 3-month mortality. Additionally, we assessed the risk of cirrhosis-related complications according to the MELD3.0 score. Results: A total of 3,314 patients were included. The mean age was 55.9±11.3 years, and 70.2% of the patients were male. Within the initial 3 months, 220 patients (6.6%) died, and the MELD3.0had the best predictive performance among the tested models, with an AUROC of 0.851, outperforming the Child-Pugh classification, ALBI grade, MELD, and MELDNa. A high MELD3.0score was associated with an increased risk of mortality. Compared with that of the group with a MELD3.0 score <10 points, the adjusted hazard ratio of the group with a score of 10–20 pointswas 2.176, and that for the group with a score of ≥20 points was 4.892. Each 1-point increase inthe MELD3.0 score increased the risk of cirrhosis-related complications by 1.033-fold. The risk of hepatorenal syndrome showed the highest increase, with an adjusted hazard ratio of 1.149, followed by hepatic encephalopathy and ascites. Conclusions The MELD3.0 demonstrated robust prognostic performance in predicting mortality in patients with cirrhosis. Moreover, the MELD3.0 score was linked to cirrhosis-related complications, particularly those involving kidney function, such as hepatorenal syndrome and ascites.