1.Age Estimation Using Convolutional Neural Networks with Lumbar and Thoracic Spine Images from Postmortem Computed Tomography: A Pilot Study
Ju-Heon LEE ; Jin-Woo KIM ; Kyung-Ryoul KIM ; In-Soo SEO ; Nak-Won LEE ; Chang-Un CHOI ; Hye-Jeong KIM ; Byung-Yoon ROH
Korean Journal of Legal Medicine 2026;50(1):1-8
In forensic medicine, age estimation commonly involves assessing age-related changes in teeth and skeletal structures. Vertebral morphological alterations, such as osteophyte formation, serve as age indicators. Recent studies using deep-learning techniques, such as neural networks, for age estimation from radiographic images have been conducted, reporting significantly higher accuracy than previous studies. This study aimed to estimate age using neural network-based deep-learning techniques applied to computed tomography (CT) cross-sectional images of the spine and evaluate its feasibility. Postmortem CT scans of 214 cadavers with varying decomposition levels were used. Coronal and sagittal cross-sectional images penetrating the center of each vertebral body were extracted for the 11th and 12th thoracic vertebrae and the first to fifth lumbar vertebrae. Using these images, along with the chronological ages of deceased individuals, an age estimation model was developed through regression analysis in PyTorch, employing a convolutional neural networks architecture with five-fold cross-validation. The model achieved a mean absolute error of 5.385 years, root mean squared error of 7.029 years, and coefficient of determination of 0.793. Although the sample size was relatively small, the results suggested the potential applicability of vertebral imagingbased age estimation in the Korean population. Further research using a larger dataset may improve the accuracy and reliability of the model.
2.Thermal modulation and airflow distribution determine hair drying efficiency, moisture behavior in human hair in Republic of Korea: an ex vivo study
Tae-Rin KWON ; Doohyun HAN ; Hyoung Jun KIM ; Jungwook KIM ; Byung Ho YOON ; Sung Yong PARK ; Jun-Seok LEE ; Na Mi BYUN ; Jungkwan LEE ; Jungwon LEE ; Kwang Ho YOO
Medical Lasers 2026;15(1):69-76
Background:
Hair drying is a routine cosmetic practice; however, excessive heat exposure and non-uniform airflow can compromise cuticle integrity, degrade hair sensory properties, and induce scalp discomfort. This study aimed to (i) identify a practical thermal window that minimizes perturbation of hair fiber surface and quantify late-stage thermal amplification during the drying process using percentage-based analysis.
Methods:
Temperature-dependent hair fiber surface morphology was examined by scanning electron microscopy (SEM) after controlled exposure to 41°C, 60°C, 80°C, and 90°C using virgin and chemically damaged hair. The drying efficacy was assessed using the surface and internal moisture indices under airflow shaping (test) and uniform airflow (control) conditions. Hair fluttering (maximum angular displacement) was evaluated before and after drying under warm-cool alternating (60°C-80°C) versus constant hot airflow (80°C).
Results:
SEM revealed temperature-dependent cuticle disruption, with markedly greater surface perturbation at 90°C than at 80°C. Infrared thermography demonstrated pronounced late-stage thermal amplification: at 150 seconds, the surface temperature increased by 295% (from 24.2°C to 72.0°C) at 90°C, compared with 207% (from 24.2°C to 50.7°C) at 80°C. Airflow shaping promoted preferential surface moisture removal (–13.6%) while limiting internal dehydration (–9.4%), whereas the control condition exhibited minimal surface drying (–4.6%) but substantial internal moisture loss (–22.2%). Warm-cool modulation increased hair fluttering by +11.0%, whereas constant hot airflow reduced it (–3.7%).
Conclusion
These findings indicate that spatial and temporal control of heat delivery represents a clinically relevant design strategy beyond the nominal temperature specification in hair-drying devices.
3.Are the long-term oncologic outcomes different between appendiceal cancer and right-sided colon cancer? An exact matching analysis of a 10-year institutional cohort
Gunwoo LEE ; Eun Jung PARK ; Soo Young OH ; Young Il KIM ; Min Hyun KIM ; Jong Lyul LEE ; Chan Wook KIM ; Yong Sik YOON ; In Ja PARK ; Seok-Byung LIM ; Chang Sik YU
Annals of Surgical Treatment and Research 2026;110(4):246-258
Purpose:
Due to its rarity, treatment guidelines for appendiceal cancer have traditionally followed those established for colorectal cancer, despite showing distinct histologic and clinical features. This study aimed to compare the clinicopathologic characteristics and long-term oncologic outcomes of appendiceal cancer with those of right-sided colon cancers.
Methods:
We retrospectively reviewed the records of patients with stage I–III appendiceal, cecal, or ascending colon cancer who underwent curative resection between 2010 and 2020 at our center. A 1:3:3 exact matching for age, sex, TNM stage, and adjuvant chemotherapy was performed. Survival outcomes were analyzed using the Kaplan-Meier and Cox regression methods.
Results:
Overall, 245 patients with appendiceal cancer (n = 35), ascending colon cancer (n = 105), and cecal cancer (n = 105) were analyzed. Appendiceal cancer exhibited a higher proportion of T4 tumors and fewer harvested lymph nodes compared with ascending or cecal cancers. The mean follow-up duration was 9.5 years. The 5- and 10-year overall survival rates were lower in appendiceal cancer (66.2% and 52.9%) than in ascending (91.2% and 78.4%) or cecal cancer (88.5% and 78.3%). Similarly, the 10-year disease-free survival rate was lower in appendiceal cancer (59.2%) compared with ascending (83.1%) and cecal cancers (78.4%). Cox regression analysis identified age (≥65 years), perforation, nodal metastasis, and lymphovascular invasion as independent predictors of poor prognosis.
Conclusion
Appendiceal cancer exhibited significantly worse long-term survival compared to cecal or ascending colon cancer. Tumor perforation, nodal metastasis, and lymphovascular invasion were adverse prognostic factors for overall and disease-free survival.
4.Real-World Experience of Weekly Carfilzomib in Combination with Cyclophosphamide and Dexamethasone in Multiple Myeloma Relapsed/Refractory to Bortezomib and Lenalidomide
Cheongin YANG ; Changgon KIM ; Kunye KWAK ; Ka-Won KANG ; Yong PARK ; Byung Soo KIM ; Seong Hyun JEONG ; Joon Seong PARK ; Yoon Seok CHOI
Cancer Research and Treatment 2026;58(1):320-328
Purpose:
This retrospective study evaluated the efficacy and safety of a weekly carfilzomib, cyclophosphamide, and dexamethasone (KCd) regimen in patients with relapsed or refractory multiple myeloma (RRMM) who had been previously treated with both bortezomib- and lenalidomide-containing regimens.
Materials and Methods:
We conducted a retrospective analysis of 33 patients with RRMM who received the KCd regimen between March 2020 and February 2024. All patients had prior exposure to both bortezomib and lenalidomide, and the majority (93.9%) were refractory to lenalidomide. Carfilzomib was administered once weekly at 70 mg/m2 (after a step-up dose), along with oral cyclophosphamide and dexamethasone. Treatment response was assessed according to the International Myeloma Working Group criteria, and survival outcomes were analyzed.
Results:
The overall response rate was 66.7%, including a complete response or better in 15.1% of patients and a very good partial response or better in 42.4%. With a median follow-up of 31.7 months, the median progression-free survival was 13.5 months (95% confidence interval, 11.47 to 15.53), while the median overall survival was not reached. The most common grade ≥ 3 adverse event was neutropenia (15.2%). Non-hematologic grade ≥ 3 toxicities were infrequent and manageable.
Conclusion
The weekly KCd regimen demonstrated encouraging efficacy and tolerability in a heavily pretreated RRMM population. These findings support its use as a feasible treatment option, particularly in patients refractory to lenalidomide.
5.Success Rate of Partial Two-Stage Exchange Arthroplasty for Late Chronic Periprosthetic Joint Infections in Total Hip Arthroplasty: A Meta-Analysis
Byung-Ho YOON ; Suyeon PARK ; Eunseo JOUNG ; Naye KANG ; Nah Yon KIM ; Ki Tae PARK
Hip & Pelvis 2026;38(2):145-154
Purpose:
Periprosthetic joint infections (PJIs) resulting from total hip arthroplasty (THA) pose significant challenges. Partial two-stage exchange arthroplasty (TSEA) retains either the femoral stem or acetabular cup by preserving bone stock and soft tissue and offers a potential alternative to total TSEA. Our meta-analysis evaluated the pooled success rate of partial TSEA in treating late chronic PJIs in THA. Our study also focused on the outcomes associated with retained prosthetic implant (stem or cup) and the type of prior surgery (primary vs. revision arthroplasty) performed.
Materials and Methods:
We analyzed data from 355 hips of patients with PJI following THA across 11 studies using a random-effects model to estimate the success rate of partial TSEA and spacer dislocation that occurs during the interval between the first and second stages of partial TSEA. The heterogeneity between the subgroups was also calculated.
Results:
The overall pooled success rate of partial TSEA in the study cohort was 87% (95% confidence interval [CI] 83-91).Lacking statistical significance (P=0.904), the success rates were 88% for stem-retained and 90% for cup-retained implant cases. The partial TSEA success rates were 88% for primary arthroplasty and 80% for revision arthroplasty, although this was not statistically significant (P=0.193). Spacer dislocation occurred in only 5% of the cases (95% CI 1-9).
Conclusion
Partial TSEA achieves high success rates comparable to those of total TSEA. Although revision arthroplasty cases carry a high risk of recurrence, partial TSEA remains a viable, tailored treatment option with a low complication rate.
6.Systemic Gaps in Heart Failure Care and the Need for Specialized Management: A Nationwide Survey of Korean Cardiologists
SungA BAE ; Soo-Yong LEE ; So-Ree KIM ; Minjae YOON ; Kang Un CHOI ; Junho HYUN ; Kyung-Hee KIM ; Suk Min SEO ; Byung-Su YOO ; Seong-Mi PARK ;
International Journal of Heart Failure 2026;8(1):95-100
7.A Practical Immunohistochemistry-Based Model for Predicting Pathologic Complete Response in Estrogen Receptor-Strong Positive and HER2-Negative Breast Cancer
Su Min LEE ; Jeong Eon LEE ; Seok Jin NAM ; Seok Won KIM ; Jonghan YU ; Byung Joo CHAE ; Se Kyung LEE ; Jai Min RYU ; Eun Yoon CHO ; Hyunwoo LEE ; Woong Ki PARK
Journal of Breast Cancer 2026;29(2):128-140
Purpose:
While the benefit of neoadjuvant chemotherapy (NAC) has been established in human epidermal growth factor receptor 2 (HER2)-positive and triple-negative breast cancers, its effectiveness in achieving pathological complete response (pCR) and optimal patient selection in estrogen receptor (ER)-positive, HER2-negative breast cancers remain less clearly defined. This study aimed to identify immunohistochemistry (IHC)-based predictors of pCR and to develop a scoring model for ER-strong positive/HER2-negative breast cancer.
Methods:
Data from a prospective cohort were retrospectively analyzed. We included 522 patients with ER-strong positive/HER2-negative tumors who received NAC and surgery between 2008 and 2021. IHC markers including progesterone receptor (PR), Ki-67, epidermal growth factor receptor (EGFR), cytokeratin 5/6 (CK5/6), and p53 were evaluated to identify predictors of pCR. Independent predictors of pCR from multivariate logistic regression were used to develop a weighted 4-point model. Model performance was assessed using receiver operating characteristic analysis. The prognostic impact of pCR was evaluated using KaplanMeier and Cox regression analyses.
Results:
Independent predictors of pCR included PR-negative status, positivity for basallike markers (EGFR or CK5/6), and Ki-67 ≥ 50%. The scoring model demonstrated good discrimination for pCR (area under the curve = 0.754). pCR rates increased stepwise, with scores of 4.9% (low), 10.7% (intermediate), and 36.2% (high). In the high-score group, pCR was significantly associated with improved disease-free survival (hazard ratio [HR], 0.09; p = 0.023) and distant metastasis-free survival (HR, 0.11; p = 0.035), whereas no significant survival differences according to pCR status were observed in the low and intermediate score groups.
Conclusion
This IHC-based model predicts pCR and helps identify subgroups in which pCR is associated with meaningful survival benefit following NAC in ER-positive/HER2-negative breast cancers. High-scoring patients may benefit from NAC, while patients with low- or intermediatescores may be better managed with surgery and endocrine therapy. This model may support personalized treatment decisions regarding NAC.
8.F‑18 FDG PET/CT Clinical Service Trends in Korea from 2018 to 2022:A National Surveillance Study
Jaesun YOON ; Heejin KIM ; Do Hyun WOO ; Seung Yeop CHAE ; Ji Heui LEE ; Inki LEE ; Ilhan LIM ; Byung Il KIM ; Chang Woon CHOI ; Byung Hyung BYUN
Nuclear Medicine and Molecular Imaging 2025;59(2):117-124
Objectives:
To assess the trends and disparities in the utilization of F-18 fluorodeoxyglucose positron emission tomography/ computed tomography (FDG PET/CT) in Korea between 2018 and 2022, with a focus on disease classification, patient demographics, and regional distribution.
Methods:
This national surveillance retrospective study uses data from the Health Insurance Review and Assessment Service (HIRA) database, which includes all FDG PET/CT examinations conducted in Korea from 2018 to 2022. Disease classifications, cancer types, age groups, gender, and geographic regions were analyzed using descriptive statistics. Utilization rates per 100,000 population were calculated for regional comparisons.
Results:
FDG PET/CT utilization increased by 25.4%, from 174,885 examinations in 2018 to 219,377 in 2022. Older age groups (60 years and above) accounted for the majority of examinations, with males undergoing more examinations than females. Oncology remained the primary indication, with lung, colorectal, and non-Hodgkin lymphoma leading in examination numbers. The number of examinations performed on patients aged 60 and above increased at a higher rate compared to those under 60. Significant geographic disparities were found, with Seoul reporting the highest utilization rate (1,114.3 examinations per 100,000 population), while Gyeongbuk exhibited much lower rate (26.2 examinations per 100,000 population).
Conclusions
This study highlights the growing utilization of FDG PET/CT in Korea, particularly among older adults, with significant gender differences in cancer types. The findings also reveal disparities in FDG PET/CT utilization across regions, indicating varying access to advanced imaging technology.
9.Machine Learning Prediction of Attachment Type From Bio-Psychological Factors in Patients With Depression
Yoon Jae CHO ; Jin Sun RYU ; Jeong-Ho SEOK ; Eunjoo KIM ; Jooyoung OH ; Byung-Hoon KIM
Psychiatry Investigation 2025;22(4):412-423
Objective:
Adult attachment style is linked to how an individual responds to threats or stress and is known to be related to the onset of psychiatric symptoms such as depression. However, as the current assessment of attachment type mainly relies on self-report questionnaires and can be prone to bias, there is a need to incorporate physiological factors along with psychological symptoms and history in this process. We aimed to predict the measurement of two important types of adult attachment with heart rate variability (HRV), early life stress experience, and subjective psychiatric symptoms.
Methods:
Five hundred eighty-two subjects with depressive disorder were recruited retrospectively from January 2015 to June 2021. The experience of early life stress and psychiatric symptoms were collected, and HRV measures were obtained as input for an ensembled Voting Regressor model of machine learning-based regression models, including linear regression, ElasticNet, Support Vector Machine (SVM), Random Forest, and Extreme Gradient Boosting (XGBoost).
Results:
Model performances evaluated with R-squared score averaged across 30 seeds were 0.377 and 0.188 for anxious- and avoidant-attachment, respectively. Mean absolute error averaged to 13.251 and 12.083, respectively. Shapley value importance analysis indicated that for both attachment types, the most important feature was the trait-anxiety, followed by emotional abuse, state-anxiety or self-reported depressive symptoms, and fear or helplessness felt in the moment of an early life stressor.
Conclusion
Our results provide the evidence base that may be utilized in clinical settings to predict the degree of attachment type using bio-psychological factors.
10.Differences in Treatment Outcomes Depending on the Adjuvant Treatment Modality in Craniopharyngioma
Byung Min LEE ; Jaeho CHO ; Dong-Seok KIM ; Jong Hee CHANG ; Seok-Gu KANG ; Eui-Hyun KIM ; Ju Hyung MOON ; Sung Soo AHN ; Yae Won PARK ; Chang-Ok SUH ; Hong In YOON
Yonsei Medical Journal 2025;66(3):141-150
Purpose:
Adjuvant treatment for craniopharyngioma after surgery is controversial. Adjuvant external beam radiation therapy (EBRT) can increase the risk of long-term sequelae. Stereotactic radiosurgery (SRS) is used to reduce treatment-related toxicity.In this study, we compared the treatment outcomes and toxicities of adjuvant therapies for craniopharyngioma.
Materials and Methods:
We analyzed patients who underwent craniopharyngioma tumor removal between 2000 and 2017. Of the 153 patients, 27 and 20 received adjuvant fractionated EBRT and SRS, respectively. We compared the local control (LC), progression-free survival (PFS), and overall survival between groups that received adjuvant fractionated EBRT, SRS, and surveillance.
Results:
The median follow-up period was 77.7 months. For SRS and surveillance, the 10-year LC was 57.2% and 57.4%, respectively. No local progression was observed after adjuvant fractionated EBRT. One patient in the adjuvant fractionated EBRT group died owing to glioma 94 months after receiving radiotherapy (10-year PFS: 80%). The 10-year PFS was 43.6% and 50.7% in the SRS and surveillance groups, respectively. The treatment outcomes significantly differed according to adjuvant treatment in nongross total resection (GTR) patients. Additional treatment-related toxicity was comparable in the adjuvant fractionated EBRT and other groups.
Conclusion
Adjuvant fractionated EBRT could be effective in controlling local failure, especially in patients with non-GTR, while maintaining acceptable treatment-related toxicity.

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