1.Artificial intelligence-based personalized oncological outcome prediction model for upper urinary tract urothelial carcinoma after radical nephroureterectomy: A development and multicenter validation
Hyun Young LEE ; Hwanik KIM ; Bumjin LIM ; Dalsan YOU ; Cheryn SONG ; In Gab JEONG ; Jun Hyuk HONG ; Bumsik HONG ; Hanjong AHN ; Seung-hwan JEONG ; Ja Hyeon KU ; Jungyo SUH
Investigative and Clinical Urology 2026;67(1):15-23
Purpose:
To develop and validate an artificial intelligence (AI)-based personalized outcome prediction model for upper-urinary tract urothelial carcinoma patients undergoing radical nephroureterectomy.
Materials and Methods:
Data from patients who underwent radical nephroureterectomy between 2010 and 2020 across three hospitals were retrospectively analyzed. A model was developed using one tertiary center’s data and externally validated with data from two other hospitals. An AI model using XGBoost as risk estimator and bootstrapped Weibull Accelerated Failure Time model for 10-year survival probability was employed. Hyperparameter tuning used Optuna method. Model efficacy was assessed using concordance index, average Brier score, D-calibration, and six-month interval time-dependent area under the curve (AUC).
Results:
Of 1,039 patients, 627 qualified after excluding 50 with neoadjuvant chemotherapy. Model development used 564 patients (507 training, 57 test) with 9:1 stratified random split, plus 63 for internal validation and 362 for external validation. Significant parameters included preoperative glomerular filtration rate (p<0.001), hydroureteronephrosis (p=0.013), pathological N stage (p<0.001), concurrent carcinoma in situ (p<0.001), disease progression (p<0.001), and survival rate (p<0.001). Disease-free survival (DFS) model’s concordance index: internal validation 0.789, external validations 0.734 and 0.771. Overall survival (OS) model’s concordance index: internal validation 0.819, external validations 0.780 and 0.771. Mean time-dependent AUC was 0.66–0.77 for DFS and 0.67–0.80 for OS during 10-year periods.
Conclusions
AI-based model effectively predicts disease-free and OS outcomes for upper-urinary tract urothelial carcinoma patients with post-radical nephroureterectomy, showcasing robust performance across multicenter settings.
2.Clinical Significance of Antinuclear Antibody Results in Patients with Uveitis
Do-Hyeon AN ; Hyun SUH ; Young-Hoon PARK ; Mirinae KIM
Journal of the Korean Ophthalmological Society 2026;67(4):110-117
Purpose:
This study investigated the results of antinuclear antibody (ANA) testing in Korean patients with uveitis, examining its relationship with the clinical course of uveitis and systemic diseases.
Methods:
We conducted a retrospective analysis of the medical records of 64 patients with noninfectious uveitis who underwent ANA testing and were followed for at least 6 months at the Department of Ophthalmology at Seoul St. Mary's Hospital from January 2006 to December 2021. Patients were divided into ANA-positive and ANA-negative groups and correlations between uveitis-related factors and ANA status were assessed.
Results:
Among the 516 patients tested for ANA, 6.58% (34/516) were positive. The initial visual acuity (logMAR) before treatment was significantly better in the ANA-positive group (0.21 ± 0.20) than in the ANA-negative group (0.59 ± 0.68) (p = 0.002). However, the final visual acuity after treatment showed no statistically significant difference between the two groups. Additionally, no statistically significant differences were observed in terms of immune deficiency status, types of associated rheumatic disease, rheumatoid factor positivity, erythrocyte sedimentation rate, C-reactive protein (define) levels, or treatment modalities. No significant correlation was found between ANA titers and the severity of uveitis.
Conclusions
Relationships between ANA positivity and the etiology, treatment outcomes, and systemic diseases associated with uveitis are unclear. Routine ANA testing is not recommended for the diagnosis of uveitis.
3.Clinical Outcome of Nunchaku-Style Silicone Tube Intubation in Patients with Nasolacrimal Duct Obstruction
Jee Hyeon OH ; Hyun Young PARK ; Jin Sook YOON ; Jaesang KO
Journal of the Korean Ophthalmological Society 2026;67(1):1-8
Purpose:
This study evaluated the long-term clinical outcomes of silicone tube intubation using a Nunchaku® (FCI Ophthalmics Inc., Pembroke, MA, USA) tube in adult patients with epiphora.
Methods:
A prospective study was conducted on 42 eyes in 32 patients who underwent silicone tube intubation with a Nunchaku® tube between March 2023 and September 2023. Clinical manifestations, Munk scale scores, lacrimal syringing test results, and tear meniscus height were assessed before and after surgery. Surgical success was defined as a Munk score of ≤ 1.
Results:
The mean age of the participants was 56.2 years. Preoperative lacrimal irrigation testing revealed partial obstruction in 29 eyes (69.0%), patent passage in 11 eyes (26.2%), and punctal stenosis in 2 eyes (4.76%). The mean operative time was 6.4 minutes for monocular procedures and 9.7 minutes for binocular procedures. At three months postoperatively, 33 eyes (78.6%) in 28 patients achieved a Munk scale score of ≤ 1. No significant differences were observed between the surgical success and failure groups in terms of preoperative Munk scale scores, lacrimal syringing test results, or tear meniscus height. One patient who underwent binocular surgery experienced worsening symptoms in both eyes postoperatively with associated punctal inflammation and granuloma formation necessitating early silicone tube removal. Slit punctum was observed in 17 eyes across 11 patients, six of whom underwent a snip procedure during surgery.
Conclusions
Silicone tube intubation using the Nunchaku-style tube is a relatively simple and effective treatment for nasolacrimal duct obstruction. However, an increased incidence of lacrimal punctum-related complications was observed compared to previous studies, indicating the need for caution when performing the snip procedure concurrently.
5.Work-life balance and effort-reward imbalance, and their interaction, associated with presenteeism among Korean wage workers: Based on 6th Korean working conditions survey
Sang-Hyeon KIM ; Eun-Chul JANG ; Soon-Chan KWON ; In-ho LEE ; Jisuk YUN ; Ui Chan JUNG ; Young-Sun MIN
Annals of Occupational and Environmental Medicine 2026;38(1):e1-
Background:
This study investigated the relationship between work-life balance (WLB), effort-reward imbalance (ERI), and presenteeism among Korean wageworkers through two models used simultaneously.
Methods:
Data from the 6th Korean Working Conditions Survey for 28,669 Korean workers, including 13,513 men and 15,156 women, were analyzed. All analyses were performed with pre-designed weight. Multiple logistic regression analysis was used to analyze the association between WLB, ERI, and presenteeism among Korean workers. The participants were classified into the following four groups: group 1, status of both WLB and ERI is “balanced”; group 2, WLB and ERI status are “imbalanced” and “balanced”, respectively; group 3, WLB and ERI status are “balanced” and “imbalanced”, respectively; group 4: status of both WLB and ERI is “imbalanced.”
Results:
We found that WLB and ERI were associated with presenteeism in both men and women. Depending on their WLB and ERI status, women generally had a higher tendency of presenteeism than men. Multiple logistic regression shows that, in most models and groups, there is an increased odds ratio (OR) for presenteeism in both men and women compared to the reference value. Moreover, the OR in both men and women gradually increased in groups 2, 3, and 4 compared with group 1. When considering both WLB and ERI status simultaneously, ERI had a greater impact on presenteeism than WLB. Furthermore, it was found that a synergistic effect of presenteeism manifests when both WLB and ERI are in a state of imbalance simultaneously.
Conclusions
Using the two models simultaneously, we found an association between WLB, ERI, and presenteeism according to sex with a synergistic effect among Korean workers. Our research suggests that active interventions targeting WLB and ERI are necessary to reduce presenteeism, which ultimately leads to decreased productivity.
6.Gastrointestinal Stromal Tumor:History, Molecular Subtypes, and Risk Stratification
In Hye SONG ; Soomin AHN ; Hyung-Don KIM ; Jeong-Hyeon JO ; Jinho SHIN ; Min-Hee RYU ; Young Soo PARK
Journal of Gastric Cancer 2026;26(2):202-218
The gastrointestinal stromal tumor (GIST) is one of the most common mesenchymal tumors of the gastrointestinal tract. Between the 1990s and early 2000s, GIST was identified as a tumor characterized by KIT or PDGFRA mutations, resulting in imatinib being established as an effective targeted therapy. However, with advances in molecular diagnostics, approximately 10%–15% of GISTs have been reported to harbor alternative mutations, such as those in the succinate dehydrogenase subunit genes and BRAF, leading to the development of additional targeted therapies. GISTs exhibit a wide spectrum of clinical behaviors, ranging from indolent to highly aggressive, prompting the development of diverse risk classification systems. However, multiple systems remain in use, leading to inconsistent pathologic reports. Moreover, the mitotic counting method—a key factor in risk stratification—has become a major source of confusion among pathologists owing to the adoption of digital pathology and discrepancies between updated international guidelines and outdated reimbursement requirements. These inconsistencies have hindered pathologic reporting and communication between pathologists and clinicians. This review comprehensively overviews the historical background, molecular subtypes, and risk classification systems of GIST, focusing on evolving issues in mitotic rate evaluation and the application of risk classification systems in clinical practice.
7.Clinical Outcomes of Trimalleolar Ankle Fractures in Patients Aged 65 Years and Older
Jun Young LEE ; Jeong Soo OH ; Jong Hyeon NAM
Journal of Korean Foot and Ankle Society 2026;30(1):14-21
Purpose:
To evaluate clinical and radiographic outcomes after the surgical treatment of trimalleolar ankle fractures in patients aged ≥65 years and to identify the prognostic factors for poor clinical outcomes.
Materials and Methods:
Sixty-three patients aged ≥65 years who underwent surgery for trimalleolar ankle fractures (2013~2022) were reviewed retrospectively. Pathologic fractures, open fractures, and follow-up <6 months were excluded. The candidate prognostic variables included the demographics, fracture classification (Lauge–Hansen and Danis–Weber), bone mineral density, body mass index, comorbidities, associated injuries, posterior malleolar fixation status, and syndesmotic injury. The reduction quality was graded using the Burwell–Charnley criteria. The outcomes were the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle–Hindfoot Score and final ambulation status. The continuous variables were compared using Student’s t-test or the Mann–Whitney U-test, and the categorical variables were analyzed using the chi-square test or Fisher’s exact test, where appropriate. Multivariable logistic regression was performed to identify the independent prognostic factors for poor clinical outcomes.
Results:
The mean age was 73.4 years, and the mean follow-up was 14.8 months; 39 patients were male, and 24 were female. Radiographic reduction was anatomic in 81.0% and fair in 19.0%. The mean time to union was 5 months, and the mean AOFAS score was 82.4. Final ambulation, limping gait, cane use, and wheelchair use were normal in 23.8%, 47.6%, 22.2%, and 6.3%, respectively. Infection and delayed union occurred in 6.3% and 9.5%, respectively, with no cases of nonunion or peri-implant fracture. Multivariable analysis showed that comorbidities and associated injuries were independently associated with poor clinical outcomes.
Conclusion
Surgical treatment generally achieved satisfactory radiographic reduction and union in patients aged ≥65 years, but functional recovery was variable, and many patients required walking aids. Comorbidities and concomitant injuries independently predicted poor outcomes, underscoring the importance of careful perioperative risk assessment and multidisciplinary postoperative management in this population.
8.Opportunistic Assessment of Coronary Artery Calcium Volume and Density From Non-Electrocardiogram-Gated Chest CT Using Artificial Intelligence:Prognostic Implications in a Screening Cohort
Na Young KIM ; Yun-Hyeon KIM ; Jong Eun LEE ; Young Joo SUH
Korean Journal of Radiology 2026;27(6):532-542
Objective:
The prognostic value of coronary artery calcium (CAC) volume and density was derived from an automated artificial intelligence (AI)-based analysis of non-electrocardiogram-gated chest CT.
Materials and Methods:
In this retrospective study, 7,552 asymptomatic adults who underwent chest CT as part of a national health screening program between 2007 and 2014 at two tertiary hospitals were examined for eligibility, of whom 1,109 with detectable CAC were analyzed. CAC density was derived by back-calculation from the Agatston score and CAC volume, both of which were obtained using AI software on chest CT. Differences in the probability of being free from major adverse cardiovascular events (MACE) across the four combined CAC volume-density groups were assessed using Kaplan–Meier curves and restricted mean survival time (RMST). Multivariable Cox proportional hazards models were used to assess the association between CAC volume and density and MACE.
Results:
Among the 1,109 participants with nonzero CAC (median age, 60.3 years; 87% men), 207 experienced MACE during a median follow-up of 7.7 years. Ten-year RMSTs were 9.45 years in the low-volume-high-density group, 9.07 years in the lowvolume-low-density group, 8.03 years in the high-volume-high-density group, and 7.68 years in the high-volume-low-density group. Differences in time to MACE were predominantly driven by CAC volume, with no significant density-related differences within the volume strata. CAC density demonstrated a significant, independent, inverse association after adjusting for CAC volume and clinical covariates (hazard ratio [HR] per increase by standard deviation [SD], 0.786; 95% confidence interval [CI], 0.659–0.936; P = 0.007). CAC volume also remained independently associated with an increased risk of MACE (HR per increase by SD, 2.608; 95% CI, 2.016–3.374; P < 0.001).
Conclusion
CAC density derived from chest CT using automated AI quantification was independently and inversely associated with MACE, providing additional prognostic value when added to CAC volume.
10.Predictors and patterns of early liver regeneration after major hepatectomy
Seoyeong KU ; Garam LEE ; Hyung Hwan MOON ; Hyungjune KU ; Won Jong YANG ; Junho SONG ; Suyeon KIM ; Chol Min KANG ; Amy CHOI ; Dong Hyeon GIM ; Young Il CHOI ; Dong Hoon SHIN ; Namkee OH ; Jinsoo RHU
Kosin Medical Journal 2026;41(1):58-66
Background:
Postoperative liver regeneration is essential for maintaining hepatic function. This study evaluated the rate, determinants, and volumetric patterns of early liver regeneration after hemihepatectomy.
Methods:
A retrospective review was conducted of 50 patients who underwent right or left hemihepatectomy between April 2019 and March 2025. Liver and spleen volumes (SV) were assessed preoperatively, at postoperative day (POD) 1 week, and at POD 3 months. Early liver regeneration rate (LRR) was defined as the percentage increase in remnant liver volume at POD 1 week relative to the preoperative future liver remnant (FLR), and patients were categorized into low (<50%) and high (≥50%) LRR groups. Clinical, biochemical, and volumetric variables were compared, and predictors of regeneration were identified using multivariable analyses. Regeneration patterns were also examined according to whether the FLR/standard liver volume (SLV) ratio was <50% or ≥50%.
Results:
FLR/SLV was the strongest independent predictor of rapid early liver regeneration (p<0.001). Remnants with FLR/SLV <50% exhibited rapid and sustained regeneration, whereas those with FLR/SLV ≥50% showed slower regrowth that plateaued after reaching approximately 90% of SLV. SV increased at POD 1 week in all patients; however, only the FLR/SLV ≥50% group showed a reduction by POD 3 months, whereas the <50% group maintained elevated volumes.
Conclusions
FLR/SLV reliably predicts early postoperative liver regeneration. Smaller remnants regenerate more rapidly, whereas persistent splenic enlargement suggests a sustained portal hemodynamic burden. Combined evaluation of FLR/SLV and SV may enhance perioperative risk assessment and surgical planning.

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