1.Deep Learning–Based Bone Age Assessment for Predicting Final Adult Height in Girls With Central Precocious Puberty
Jeong Min SONG ; Pyeong Hwa KIM ; Young Ah CHO ; Ah Young JUNG ; Jin Seong LEE ; Ja Hye KIM ; Hee Mang YOON
Korean Journal of Radiology 2026;27(6):568-577
Objective:
This study aimed to evaluate the accuracy of predicting final adult height (FAH) in Korean girls with central precocious puberty (CPP) using artificial intelligence (AI)-derived bone age assessments integrated into the Bayley–Pinneau (BP) or Korean National Growth Chart (KGC) prediction models.
Materials and Methods:
This single-center, retrospective study included 122 Korean girls with CPP who received gonadotropinreleasing hormone agonist (GnRHa) treatment for at least two years between January 2000 and November 2022. We assessed bone age and predicted adult height at the initiation and completion of GnRHa treatment. We used three bone age assessment methods: human expert assessment based on the Greulich-Pyle (GP) atlas (Human-GP), AI-derived GP (AI-GP), and AI-weighted GP scoring (AI-GPw). We calculated predicted adult heights (PAHs) using both the BP and KGC models, generating 12 PAH estimates per patient (2 time points x 3 bone-age methods x 2 height-prediction models). We assessed prediction accuracy and agreement with FAH using linear regression analysis and Bland–Altman plots and performed multivariable analysis to identify significant predictors of FAH.
Results:
Human-GP, AI-GP, and AI-GPw demonstrated comparable overall performance in predicting FAH (R 2 : 0.470–0.646 and 0.691–0.822 for treatment initiation and completion, respectively). AI-GPw combined with BP yielded slightly better point estimates but showed no statistically significant differences. At both time points, the BP model demonstrated consistently narrower 95% limits of agreement (LoA) than the KGC model. Multivariable analysis identified AI-GPw-BP and height percentile score as significant predictors of FAH at both time points; mid-parental height was significant only at treatment initiation.
Conclusion
Human-GP, AI-GP, and AI-GPw demonstrated comparable accuracy in predicting FAH. The BP model demonstrated consistently narrower 95% LoA than did the KGC model. AI-GPw-BP was an independent predictor of FAH. These findings support the clinical utility of AI-derived bone age assessments for individualized FAH prediction in patients with CPP.
2.Clinical Guideline for the Use of Biodegradable Rectal Spacers During Radiotherapy for Prostate Cancer
Hyun Ho HAN ; Jong Kyou KWON ; Do Kyung KIM ; Jin Hyung JEON ; Chan Woo WEE ; Jae Ho CHO ; Ji Hee JUNG ; A Young YOO ; Jae Young JOUNG ; Gee Hyun SONG ; Seung Ju LEE ; Won PARK ; Chan Kyo KIM ; Young Seok KIM ; Yeon Joo KIM ; Ah Ram CHANG ; Jae Sik KIM ; Sung Hwan BAE ; Byoung Kyu HAN ; Kang Su CHO
Journal of Urologic Oncology 2026;24(1):3-12
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.
3.Associated factors of osteoporosis and the impact of osteoporosis on all-cause mortality in incident hemodialysis older patients
Seunghye LEE ; Yoomee KANG ; Yu Ah HONG ; Sung Joon SHIN ; Soon Hyo KWON ; Sungjin CHUNG ; Young Youl HYUN ; Sang Heon SONG ; Jae Won YANG ; Won Min HWANG ; Jang-Hee CHO ; Kyung Don YOO ; In O SUN ; Gang-Jee KO ; Byung Chul YU ; Hyunsuk KIM ; Woo Yeong PARK ; Tae Won LEE ; Dong Jun PARK ; Eunjin BAE ;
Kidney Research and Clinical Practice 2026;45(1):110-119
Background:
With the aging population and advancements in medical care worldwide, the number of older patients with end-stage kidney disease continues to rise. This study aimed to identify factors associated with osteoporosis and osteopenia in older patients undergoing incident hemodialysis and assess their impact on mortality.
Methods:
We analyzed a large multicenter retrospective cohort of patients aged ≥70 years undergoing incident hemodialysis to identify factors associated with osteoporosis using logistic regression analysis and to assess the association of death with osteoporosis and osteopenia using Cox multivariable analysis.
Results:
Among 710 patients, 39.0% and 19.6% had osteoporosis and osteopenia, respectively. Osteoporosis was significantly associated with female sex, a history of fractures, and the absence of phosphate binder use. During a median follow-up of 36.8 months, 348 participants (58.8%) died. Mortality rates were the highest in the osteoporosis group (79.8%), followed by the osteopenia (77.2%) and normal bone mineral density (BMD) groups (35.2%). Cox regression analysis revealed that even after adjusting for covariates, the osteoporosis group was significantly associated with a higher mortality risk than the normal BMD group. Osteoporosis at the start of hemodialysis was significantly associated with higher mortality.
Conclusion
We should consider the importance of bone health in patients undergoing incident hemodialysis and pay attention to the use of phosphate binders and fracture prevention.
4.Impact of obesity on renal function in elderly Korean adults: a national population-based cohort study
Jihyun YANG ; Hui Seung LEE ; Chi-Yeon LIM ; Hyunsuk KIM ; Sungjin CHUNG ; Soon Hyo KWON ; Jang-Hee CHO ; Kyung Don YOO ; Woo Yeong PARK ; In O SUN ; Byung Chul YU ; Gang-Jee KO ; Jae Won YANG ; Won Min HWANG ; Sang Heon SONG ; Sung Joon SHIN ; Yu Ah HONG ; Eunjin BAE ; Young Youl HYUN
Kidney Research and Clinical Practice 2026;45(1):65-76
Background:
Obesity is a well-known risk factor for chronic kidney disease and its progression. However, the impact of obesity on the renal function of the elderly population is uncertain. We investigated the association between obesity and renal outcomes in the elderly.
Methods:
We analyzed 130,504 participants from the Korean National Health Insurance Service-Senior cohort. Obesity was classified according to body mass index (BMI), sex-specific waist circumference (WC), and the presence of metabolic syndrome. The primary outcome was renal function decline, defined as a decline in the estimated glomerular filtration rate (eGFR) of at least 50% from baseline or new-onset end-stage renal disease.
Results:
During a follow-up period of 559,531.1 person-years (median, 4.3 years), 2,486 participants (19.0%; incidence rate of 4.44 per 1,000 person-years) showed renal function decline. A multivariate Cox proportional hazards model revealed that BMI/WC was not associated with renal function decline. However, the group with metabolic syndrome had a significantly increased risk of renal function decline compared to the group without metabolic syndrome (adjusted hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.13–1.36). Compared with the non-metabolic syndrome group, the adjusted HRs (95% CI) for participants with one through five components were 0.96 (0.84–1.11), 1.10 (0.96–1.27), 1.24 (1.06–1.45), 1.37 (1.12–1.66), and 1.99 (1.42–2.79), respectively (p for trend < 0.001).
Conclusion
In elderly Korean adults, metabolic syndrome and the number of its components were associated with a higher risk of renal function decline, but BMI or WC was not significant.
5.Sequential Mediation by Maternal Weight Gain and Late Blood Metal Concentration in the Association Between Heavy Metal Exposure in Early Pregnancy and Fetal Growth
Seung-Ah CHOE ; Jue Seong LEE ; Changmin KANG ; Jungheum JO ; Wonsuck YOON ; Dae Jin SONG ; Young YOO ;
Journal of Korean Medical Science 2026;41(1):e16-
Background:
To assess the mediation effect of gestational weight gain (GWG) and blood heavy metal levels in the late pregnancy affecting the association between early pregnancy metal exposure and fetal growth.
Methods:
We analyzed data from Korean Children’s Environmental Health Study cohort comprising 4,712 full-term births. Blood levels of lead (Pb), mercury (Hg), and cadmium (Cd) during pregnancy, and newborn birthweights were retrieved. We applied single-exposure model to assess the association between heavy metal levels and newborn anthropometric measures and conducted path analyses to examine the direct and indirect effects of heavy metal levels in early pregnancy on newborn measures.
Results:
Exposure to Pb (β = −15.470, P = 0.036) and Cd (β = −24.150, P = 0.004) during late pregnancy were associated with lower birthweight. Early exposure to Pb was not directly associated with lower birthweight, however, mediation of late exposure to Pb (β = −7.417, P = 0.049) resulted in lower birthweight (β = −14.787, P = 0.036). Early exposure to Hg was associated with higher birthweight, however, indirect paths via GWG (β = 3.626, P = 0.048) and late Hg levels (β = −12.929, P = 0.111) countered each other, resulting in the nullification of the total effect (β = −8.519, P = 0.301).
Conclusion
The effect of Pb exposure in early pregnancy on birthweight was mediated by GWG and Pb exposures during late pregnancy. When assessing the impact of heavy metal exposure on birthweight, it is important to note that GWG and late heavy metal levels act as mediators, rather than confounders.
6.Application of Machine Learning Algorithms for Risk Stratification and Efficacy Evaluation in Cervical Cancer Screening among the ASCUS/LSIL Population: Evidence from the Korean HPV Cohort Study
Heekyoung SONG ; Hong Yeon LEE ; Shin Ah OH ; Jaehyun SEONG ; Soo Young HUR ; Youn Jin CHOI
Cancer Research and Treatment 2025;57(2):547-557
Purpose:
We assessed human papillomavirus (HPV) genotype-based risk stratification and the efficacy of cytology testing for cervical cancer screening in patients with atypical squamous cells of undetermined significance (ASCUS)/low-grade squamous intraepithelial lesion (LSIL).
Materials and Methods:
Between 2010 and 2021, we monitored 1,273 HPV-positive women with ASCUS/LSIL every 6 months for up to 60 months. HPV infections were categorized as persistent (HPV positivity consistently observed post-enrollment), negative (HPV negativity consistently observed post-enrollment), or non-persistent (neither consistently positive nor negative). HPV genotypes were grouped into high-risk (Hr) groups 1 (types 16, 18, 31, 33, 45, 52, and 58) and 2 (types 35, 39, 51, 56, 59, 66, and 68) and a low-risk group. Hr1 was subdivided into types (a) 16 and 18; (b) 31, 33, and 45; and (c) 52 and 58. Cox regression and machine learning (ML) algorithms were used to analyze progression rates.
Results:
Among 1,273 participants, 17.6% with persistent HPV infections experienced disease progression versus no progression in the HPV-negative group (p < 0.001). Cox analysis revealed the highest hazard ratios (HRs) for Hr1-a (11.6, p < 0.001), followed by Hr1-b (9.26, p < 0.001) and Hr1-c (7.21, p < 0.001). HRs peaked at 12-24 months, with Hr1-a maintaining significance at 24-36 months (10.7, p=0.034). ML analysis identified the final cytology change pattern as the most significant factor, with 14-15 months the optimal time for detecting progression from the first examination.
Conclusion
In ASCUS/LSIL cases, follow-up strategies should be based on HPV risk types. Annual follow-up was the most effective monitoring for detecting progression/regression.
7.Application of Machine Learning Algorithms for Risk Stratification and Efficacy Evaluation in Cervical Cancer Screening among the ASCUS/LSIL Population: Evidence from the Korean HPV Cohort Study
Heekyoung SONG ; Hong Yeon LEE ; Shin Ah OH ; Jaehyun SEONG ; Soo Young HUR ; Youn Jin CHOI
Cancer Research and Treatment 2025;57(2):547-557
Purpose:
We assessed human papillomavirus (HPV) genotype-based risk stratification and the efficacy of cytology testing for cervical cancer screening in patients with atypical squamous cells of undetermined significance (ASCUS)/low-grade squamous intraepithelial lesion (LSIL).
Materials and Methods:
Between 2010 and 2021, we monitored 1,273 HPV-positive women with ASCUS/LSIL every 6 months for up to 60 months. HPV infections were categorized as persistent (HPV positivity consistently observed post-enrollment), negative (HPV negativity consistently observed post-enrollment), or non-persistent (neither consistently positive nor negative). HPV genotypes were grouped into high-risk (Hr) groups 1 (types 16, 18, 31, 33, 45, 52, and 58) and 2 (types 35, 39, 51, 56, 59, 66, and 68) and a low-risk group. Hr1 was subdivided into types (a) 16 and 18; (b) 31, 33, and 45; and (c) 52 and 58. Cox regression and machine learning (ML) algorithms were used to analyze progression rates.
Results:
Among 1,273 participants, 17.6% with persistent HPV infections experienced disease progression versus no progression in the HPV-negative group (p < 0.001). Cox analysis revealed the highest hazard ratios (HRs) for Hr1-a (11.6, p < 0.001), followed by Hr1-b (9.26, p < 0.001) and Hr1-c (7.21, p < 0.001). HRs peaked at 12-24 months, with Hr1-a maintaining significance at 24-36 months (10.7, p=0.034). ML analysis identified the final cytology change pattern as the most significant factor, with 14-15 months the optimal time for detecting progression from the first examination.
Conclusion
In ASCUS/LSIL cases, follow-up strategies should be based on HPV risk types. Annual follow-up was the most effective monitoring for detecting progression/regression.
8.Application of Machine Learning Algorithms for Risk Stratification and Efficacy Evaluation in Cervical Cancer Screening among the ASCUS/LSIL Population: Evidence from the Korean HPV Cohort Study
Heekyoung SONG ; Hong Yeon LEE ; Shin Ah OH ; Jaehyun SEONG ; Soo Young HUR ; Youn Jin CHOI
Cancer Research and Treatment 2025;57(2):547-557
Purpose:
We assessed human papillomavirus (HPV) genotype-based risk stratification and the efficacy of cytology testing for cervical cancer screening in patients with atypical squamous cells of undetermined significance (ASCUS)/low-grade squamous intraepithelial lesion (LSIL).
Materials and Methods:
Between 2010 and 2021, we monitored 1,273 HPV-positive women with ASCUS/LSIL every 6 months for up to 60 months. HPV infections were categorized as persistent (HPV positivity consistently observed post-enrollment), negative (HPV negativity consistently observed post-enrollment), or non-persistent (neither consistently positive nor negative). HPV genotypes were grouped into high-risk (Hr) groups 1 (types 16, 18, 31, 33, 45, 52, and 58) and 2 (types 35, 39, 51, 56, 59, 66, and 68) and a low-risk group. Hr1 was subdivided into types (a) 16 and 18; (b) 31, 33, and 45; and (c) 52 and 58. Cox regression and machine learning (ML) algorithms were used to analyze progression rates.
Results:
Among 1,273 participants, 17.6% with persistent HPV infections experienced disease progression versus no progression in the HPV-negative group (p < 0.001). Cox analysis revealed the highest hazard ratios (HRs) for Hr1-a (11.6, p < 0.001), followed by Hr1-b (9.26, p < 0.001) and Hr1-c (7.21, p < 0.001). HRs peaked at 12-24 months, with Hr1-a maintaining significance at 24-36 months (10.7, p=0.034). ML analysis identified the final cytology change pattern as the most significant factor, with 14-15 months the optimal time for detecting progression from the first examination.
Conclusion
In ASCUS/LSIL cases, follow-up strategies should be based on HPV risk types. Annual follow-up was the most effective monitoring for detecting progression/regression.
9.A Novel Fibrinogen Assay Using Recombinant Batroxobin and Carboxymethyl Chitosan:Carboxymethyl Chitosan Stimulates the Enzymatic Activity of Recombinant Batroxobin
Jung-Ah KIM ; Eunhye KO ; Yongje WOO ; Young-Doug SOHN ; Jong-Tak KIM ; Jaewoo SONG ; Rojin PARK
Annals of Laboratory Medicine 2025;45(5):484-492
Background:
The Clauss assay is widely used to quantify blood fibrinogen levels in clinical laboratories. However, by relying on thrombin as the main reagent, the Clauss assay is susceptible to interference from thrombin inhibitors, such as heparin or direct thrombin inhibitors. Here, we developed an innovative fibrinogen assay utilizing both recombinant batroxobin (rBat) and carboxymethyl chitosan (CMCS).
Methods:
Various biopolymers were tested to identify a suitable candidate that could enhance rBat-induced fibrin clot formation. Chromogenic substrate hydrolysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed that CMCS potentiated rBat activity. Consequently, we formulated a novel fibrinogen assay reagent, ANYFIB.C, comprising rBat and CMCS. We compared ANYFIB.C fibrinogen with an established reagent (HemosIL fibrinogen-C) with 96 clinical samples using an ACL-TOP 700 coagulation analyzer. We also evaluated the interfering effects of thrombin inhibitors on fibrinogen measurements.
Results:
CMCS significantly enhanced the enzymatic activity of rBat and dose-dependently reduced plasma clotting times. ANYFIB.C fibrinogen levels were comparable with those of HemosIL fibrinogen-C, with the 95% confidence intervals of the Passing–Bablok regres-sion intercept and slope being −7.4797 to 6.0185 and 0.9581 to 1.0116, respectively. Nosignificant interference was observed with heparin concentrations up to 10 U/mL or dabigatran concentrations up to 600 µg/L in the ANYFIB.C fibrinogen assays. In contrast, the HemosIL fibrinogen-C reagent demonstrated inhibitory interference at dabigatran concentrations as low as 150 µg/L.
Conclusions
Our results suggest that ANYFIB.C (a mixture of CMCS and rBat) can be used to measure blood fibrinogen levels effectively and protect from thrombin inhibitor interference.
10.11α-hydroxyprogesterone dampens lung metastasis via EMT modulation in PyMTinduced breast cancer murine model
Narim KIM ; Jinhee LEE ; Ah Young SONG ; Moeka MUKAE ; Beum-Soo AN ; Eui-Ju HONG
Laboratory Animal Research 2025;41(4):307-316
Background:
Despite the availability of various therapeutic strategies, the prognosis for patients with metastatic breast cancer remains poor. Epithelial-mesenchymal transition (EMT) is a critical mechanism driving metastasis in breast cancer, enabling tumor cells to lose epithelial characteristics and acquire enhanced motility and invasiveness.
Results:
This study investigates the role of 11alpha-hydroxyprogesterone (11α-OHP), a steroid hormone with an incompletely understood biosynthesis and metabolic pathway, in regulating lung metastasis in breast cancer. Using the MMTV-PyMT FVB mouse model, which spontaneously develops breast tumors we administered 11α-OHP for five weeks starting at 10 weeks of age. At 15 weeks, histological analysis revealed a significant reduction in lung metastasis in 11α-OHP-treated mice compared to controls, with notably smaller metastatic tumor areas in the lungs. Additionally, treated mice exhibited increased expression of epithelial cell adhesion proteins and decreased levels of focal adhesion kinase (FAK) in lung tissues. In vitro experiments using MDA-MB-231 cells corroborated these findings, showing that 11α-OHP significantly inhibited cell motility and invasiveness in scratch wound, transwell migration, and invasion assays. Notably, 11α-OHP did not significantly alter primary tumor growth in the MMTV-PyMT model.
Conclusions
These findings suggest that 11α-OHP may suppress breast cancer metastasis by modulating EMT, highlighting its potential as a therapeutic target for preventing metastatic progression.

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