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.En bloc capsulectomy of a pseudocyst-like pocket after a massive filler injection into the buttocks: two case reports
Kyung Min KIM ; Jeong Hun AHN ; Ki Hyun KIM ; Sang Seok WOO ; Jun Won LEE ; Seong Hwan KIM ; Jai Koo CHOI ; Insuck SUH
Archives of Aesthetic Plastic Surgery 2026;32(2):26-31
Buttock augmentation is an increasingly popular cosmetic procedure designed to enhance buttock contour, size, and shape. However, the safety profile of this procedure remains insufficiently established, and it carries risks of complications, including foreign body reactions and infections. These complications may be exacerbated by filler migration, resulting in large soft-tissue cavities that resemble pseudocysts. In this study, we describe two patients who developed severe complications following massive filler injections to the buttocks. A 56-year-old female patient presented with a 6×5 cm soft-tissue defect associated with an extensive underlying dead space, sinus tract formation, and a large pocket extending across the buttock. Additionally, a 50-year-old female patient developed diffuse cellulitis and multiple abscesses secondary to migration of an infected filler-related pseudocyst. Both patients underwent successful en bloc capsulectomy, resulting in marked clinical improvement without recurrence or postoperative complications. These cases underscore the serious complications associated with large-volume filler injections and highlight the importance of comprehensive surgical management in addressing late-stage adverse outcomes.
3.Delayed Retroperitoneal Hematoma Following Intradiscal Electrothermal Therapy: A Case Report of a Rare Complication
Jun-Yong CHA ; Yun-Young PARK ; Jin-Uk KIM ; Jun-Ho LEE ; Seong-Hwan MUN ; Gun AHN ; Il-Tae JANG
The Nerve 2026;12(1):36-40
Intradiscal electrothermal therapy (IDET) is a minimally invasive procedure used to treat discogenic back pain and offers an alternative to surgical intervention in selected patients. Although it is generally considered safe, rare but significant complications can occur and may be difficult to diagnose because their symptoms overlap with those of other spinal conditions. We describe the case of a 69-year-old woman who presented with severe lower back and left buttock pain that was unresponsive to conservative treatment. Magnetic resonance imaging revealed disc bulging with a high-intensity zone at the L4–5 and L5–S1 levels. IDET was performed at the L4–5 level, resulting in initial pain relief. However, the patient returned 7 days later with recurrent pain. Despite undergoing percutaneous epidural neuroplasty at the left L5–S1 level, a medial branch block, and a piriformis muscle block, her symptoms persisted. Further evaluation with spinal computed tomography revealed a retroperitoneal hematoma near the left psoas muscle. Referred pain from the hematoma mimicked discogenic pain, resulting in delayed diagnosis and unnecessary interventions. The patient remained hemodynamically stable and gradually improved with conservative management alone. This case highlights retroperitoneal hematoma as a rare complication of IDET and emphasizes the importance of accurate and timely diagnosis in patients with persistent or worsening symptoms after spinal procedures. Clinicians should consider non-discogenic sources of pain when treatment outcomes deviate from expected patterns.
4.Germline Mutations Related to Complete Remission After Neoadjuvant Chemotherapy in Patients With Triple-negative Breast Cancer
Jee Hyun AHN ; Ji Soo PARK ; Dongju WON ; Seung-Tae LEE ; Suk Jun LEE ; Seung Hye YANG ; Jee Ye KIM ; Seho PARK ; Seung Il KIM ; Byeong-Woo PARK ; Min Hwan KIM ; Gun Min KIM ; Joohyuk SOHN ; Hyung Seok PARK
Journal of Breast Cancer 2026;29(2):118-127
Purpose:
Triple-negative breast cancer (TNBC) is a frequent phenotype of BRCA-mutanttumors. Tumors with BRCAness may show characteristics of BRCA-mutant tumors and respond to similar treatments. Next-generation sequencing is an efficient and cost-effective method for simultaneously sequencing multiple cancer susceptibility genes, surpassing conventional Sanger testing.
Methods:
A total of 148 women with TNBC were recruited from December 2015 to November 2018, as part of a sub-analysis based on the PEARLY trial data. Of them, 103 patients received neoadjuvant chemotherapy (NCT). The targeted genes related to hereditary cancers were sequenced using the 65-gene germline next-generation sequencing (gNGS) panel pathogenic and likely pathogenic variants (P&LPs) were determined by Sanger sequencing. We examined the occurrence of pathologic complete remission (ypCR) in patients with P&LPs.
Results:
The patients’ median age was 47 years (range, 27–69 years). Twenty (13.7%) of 148 patients had P&LP in six genes, including BARD1 (n = 2), BRCA1 (n = 9), BRCA2 (n = 5), CHEK2 (n = 1), RAD51C (n = 1), and RAD51D (n = 2). Among the 103 patients with NCT, 43 (41.7%) achieved ypCR (P&LPs; 9 individuals vs. non-variants; 34 individuals). Among the 103 patients with NCT, 14 (9.3%) had P&LPs. Nine of 14 patients with P&LPs, including BARD1 (n = 2), BRCA1 (n = 4), BRCA2 (n = 1), RAD51C (n = 1), and RAD51D (n = 1), achieved ypCR, showing a trend toward statistical significance (p = 0.066).
Conclusion
Germline P&LP mutations in TNBC patients can be detected by gNGS. This panel test can identify BRCA and BRCAness mutations that may predict ypCR in TNBC.
5.Sex Differences in Procedural Characteristics and Clinical Outcomes Among Patients Undergoing Bifurcation PCI
Hyun Jin AHN ; Francesco BRUNO ; Jeehoon KANG ; Doyeon HWANG ; Han-Mo YANG ; Jung-Kyu HAN ; Leonardo De LUCA ; Ovidio de FILIPPO ; Alessio MATTESINI ; Kyung Woo PARK ; Alessandra TRUFFA ; Wojciech WANHA ; Young Bin SONG ; Sebastiano GILI ; Woo Jung CHUN ; Gerard HELFT ; Seung-Ho HUR ; Bernardo CORTESE ; Seung Hwan HAN ; Javier ESCANED ; Alaide CHIEFFO ; Ki Hong CHOI ; Guglielmo GALLONE ; Joon-Hyung DOH ; Gaetano De FERRARI ; Soon-Jun HONG ; Giorgio QUADRI ; Chang-Wook NAM ; Hyeon-Cheol GWON ; Hyo-Soo KIM ; Fabrizio D’ASCENZO ; Bon-Kwon KOO
Korean Circulation Journal 2025;55(1):5-16
Background and Objectives:
The risk profiles, procedural characteristics, and clinical outcomes for women undergoing bifurcation percutaneous coronary intervention (PCI) are not well defined compared to those in men.
Methods:
COronary BIfurcation Stenting III (COBIS III) is a multicenter, real-world registry of 2,648 patients with bifurcation lesions treated with second-generation drug-eluting stents.We compared the angiographic and procedural characteristics and clinical outcomes based on sex. The primary outcome was 5-year target lesion failure (TLF), a composite of cardiac death, myocardial infarction, and target lesion revascularization.
Results:
Women (n=635, 24%) were older, had hypertension and diabetes more often, and had smaller main vessel and side branch reference diameters than men. The pre- and post-PCI angiographic percentage diameter stenoses of the main vessel and side branch were comparable between women and men. There were no differences in procedural characteristics between the sexes. Women and men had a similar risk of TLF (6.3% vs. 7.1%, p=0.63) as well as its individual components and sex was not an independent predictor of TLF. This finding was consistent in the left main and 2 stenting subgroups.
Conclusions
In patients undergoing bifurcation PCI, sex was not an independent predictor of adverse outcome.
6.Study on the Necessity and Methodology for Enhancing Outpatient and Clinical Education in the Department of Radiology
Soo Buem CHO ; Jiwoon SEO ; Young Hwan KIM ; You Me KIM ; Dong Gyu NA ; Jieun ROH ; Kyung-Hyun DO ; Jung Hwan BAEK ; Hye Shin AHN ; Min Woo LEE ; Seunghyun LEE ; Seung Eun JUNG ; Woo Kyoung JEONG ; Hye Doo JEONG ; Bum Sang CHO ; Hwan Jun JAE ; Seon Hyeong CHOI ; Saebeom HUR ; Su Jin HONG ; Sung Il HWANG ; Auh Whan PARK ; Ji-hoon KIM
Journal of the Korean Society of Radiology 2025;86(1):199-200
7.Early Administration of Nelonemdaz May Improve the Stroke Outcomes in Patients With Acute Stroke
Jin Soo LEE ; Ji Sung LEE ; Seong Hwan AHN ; Hyun Goo KANG ; Tae-Jin SONG ; Dong-Ick SHIN ; Hee-Joon BAE ; Chang Hun KIM ; Sung Hyuk HEO ; Jae-Kwan CHA ; Yeong Bae LEE ; Eung Gyu KIM ; Man Seok PARK ; Hee-Kwon PARK ; Jinkwon KIM ; Sungwook YU ; Heejung MO ; Sung Il SOHN ; Jee Hyun KWON ; Jae Guk KIM ; Young Seo KIM ; Jay Chol CHOI ; Yang-Ha HWANG ; Keun Hwa JUNG ; Soo-Kyoung KIM ; Woo Keun SEO ; Jung Hwa SEO ; Joonsang YOO ; Jun Young CHANG ; Mooseok PARK ; Kyu Sun YUM ; Chun San AN ; Byoung Joo GWAG ; Dennis W. CHOI ; Ji Man HONG ; Sun U. KWON ;
Journal of Stroke 2025;27(2):279-283
8.Sex Differences in Procedural Characteristics and Clinical Outcomes Among Patients Undergoing Bifurcation PCI
Hyun Jin AHN ; Francesco BRUNO ; Jeehoon KANG ; Doyeon HWANG ; Han-Mo YANG ; Jung-Kyu HAN ; Leonardo De LUCA ; Ovidio de FILIPPO ; Alessio MATTESINI ; Kyung Woo PARK ; Alessandra TRUFFA ; Wojciech WANHA ; Young Bin SONG ; Sebastiano GILI ; Woo Jung CHUN ; Gerard HELFT ; Seung-Ho HUR ; Bernardo CORTESE ; Seung Hwan HAN ; Javier ESCANED ; Alaide CHIEFFO ; Ki Hong CHOI ; Guglielmo GALLONE ; Joon-Hyung DOH ; Gaetano De FERRARI ; Soon-Jun HONG ; Giorgio QUADRI ; Chang-Wook NAM ; Hyeon-Cheol GWON ; Hyo-Soo KIM ; Fabrizio D’ASCENZO ; Bon-Kwon KOO
Korean Circulation Journal 2025;55(1):5-16
Background and Objectives:
The risk profiles, procedural characteristics, and clinical outcomes for women undergoing bifurcation percutaneous coronary intervention (PCI) are not well defined compared to those in men.
Methods:
COronary BIfurcation Stenting III (COBIS III) is a multicenter, real-world registry of 2,648 patients with bifurcation lesions treated with second-generation drug-eluting stents.We compared the angiographic and procedural characteristics and clinical outcomes based on sex. The primary outcome was 5-year target lesion failure (TLF), a composite of cardiac death, myocardial infarction, and target lesion revascularization.
Results:
Women (n=635, 24%) were older, had hypertension and diabetes more often, and had smaller main vessel and side branch reference diameters than men. The pre- and post-PCI angiographic percentage diameter stenoses of the main vessel and side branch were comparable between women and men. There were no differences in procedural characteristics between the sexes. Women and men had a similar risk of TLF (6.3% vs. 7.1%, p=0.63) as well as its individual components and sex was not an independent predictor of TLF. This finding was consistent in the left main and 2 stenting subgroups.
Conclusions
In patients undergoing bifurcation PCI, sex was not an independent predictor of adverse outcome.
9.Characteristics and Prevalence of Sequelae after COVID-19: A Longitudinal Cohort Study
Se Ju LEE ; Yae Jee BAEK ; Su Hwan LEE ; Jung Ho KIM ; Jin Young AHN ; Jooyun KIM ; Ji Hoon JEON ; Hyeri SEOK ; Won Suk CHOI ; Dae Won PARK ; Yunsang CHOI ; Kyoung-Ho SONG ; Eu Suk KIM ; Hong Bin KIM ; Jae-Hoon KO ; Kyong Ran PECK ; Jae-Phil CHOI ; Jun Hyoung KIM ; Hee-Sung KIM ; Hye Won JEONG ; Jun Yong CHOI
Infection and Chemotherapy 2025;57(1):72-80
Background:
The World Health Organization has declared the end of the coronavirus disease 2019 (COVID-19) public health emergency. However, this did not indicate the end of COVID-19. Several months after the infection, numerous patients complain of respiratory or nonspecific symptoms; this condition is called long COVID. Even patients with mild COVID-19 can experience long COVID, thus the burden of long COVID remains considerable. Therefore, we conducted this study to comprehensively analyze the effects of long COVID using multi-faceted assessments.
Materials and Methods:
We conducted a prospective cohort study involving patients diagnosed with COVID-19 between February 2020 and September 2021 in six tertiary hospitals in Korea. Patients were followed up at 1, 3, 6, 12, 18, and 24 months after discharge. Long COVID was defined as the persistence of three or more COVID-19-related symptoms. The primary outcome of this study was the prevalence of long COVID after the period of COVID-19.
Results:
During the study period, 290 patients were enrolled. Among them, 54.5 and 34.6% experienced long COVID within 6 months and after more than 18 months, respectively. Several patients showed abnormal results when tested for post-traumatic stress disorder (17.4%) and anxiety (31.9%) after 18 months. In patients who underwent follow-up chest computed tomography 18 months after COVID-19, abnormal findings remained at 51.9%. Males (odds ratio [OR], 0.17; 95% confidence interval [CI], 0.05–0.53; P=0.004) and elderly (OR, 1.04; 95% CI, 1.00–1.09; P=0.04) showed a significant association with long COVID after 12–18 months in a multivariable logistic regression analysis.
Conclusion
Many patients still showed long COVID after 18 months post SARS-CoV-2 infection. When managing these patients, the assessment of multiple aspects is necessary.
10.Establishing Regional Aβ Cutoffs andExploring Subgroup Prevalence Across Cognitive Stages Using BeauBrain Amylo®
Seongbeom PARK ; Kyoungmin KIM ; Soyeon YOON ; Seongmi KIM ; Jehyun AHN ; Kyoung Yoon LIM ; Hyemin JANG ; Duk L. NA ; Hee Jin KIM ; Seung Hwan MOON ; Jun Pyo KIM ; Sang Won SEO ; Jaeho KIM ; Kichang KWAK
Dementia and Neurocognitive Disorders 2025;24(2):135-146
Background:
and Purpose: Amyloid-beta (Aβ) plaques are key in Alzheimer’s disease (AD), with Aβ positron emission tomography imaging enabling non-invasive quantification.To address regional Aβ deposition, we developed regional Centiloid scales (rdcCL) and commercialized them through the computed tomography (CT)-based BeauBrain Amylo platform, eliminating the need for three-dimensional T1 magnetic resonance imaging (MRI).
Objective:
We aimed to establish robust regional Aβ cutoffs using the commercialized BeauBrain Amylo platform and to explore the prevalence of subgroups defined by global, regional, and striatal Aβ cutoffs across cognitive stages.
Methods:
We included 2,428 individuals recruited from the Korea-Registries to Overcome Dementia and Accelerate Dementia Research project. We calculated regional Aβ cutoffs using Gaussian Mixture Modeling. Participants were classified into subgroups based on global, regional, and striatal Aβ positivity across cognitive stages (cognitively unimpaired [CU], mild cognitive impairment, and dementia of the Alzheimer’s type).
Results:
MRI-based and CT-based global Aβ cutoffs were highly comparable and consistent with previously reported Centiloid values. Regional cutoffs revealed both similarities and differences between MRI- and CT-based methods, reflecting modality-specific segmentation processes. Subgroups such as global(−)regional(+) were more frequent in non-dementia stages, while global(+)striatal(−) was primarily observed in CU individuals.
Conclusions
Our study established robust regional Aβ cutoffs using a CT-based rdcCL method and demonstrated its clinical utility in classifying amyloid subgroups across cognitive stages. These findings highlight the importance of regional Aβ quantification in understanding amyloid pathology and its implications for biomarker-guided diagnosis and treatment in AD.

Result Analysis
Print
Save
E-mail