1.Regenerative Capacity of Alveolar Type 2 Cells Is Proportionally Reduced Following Disease Progression in Idiopathic Pulmonary Fibrosis-Derived Organoid Cultures
Hyeon Kyu CHOI ; Gaeul BANG ; Ju Hye SHIN ; Mi Hwa SHIN ; Ala WOO ; Song Yee KIM ; Sang Hoon LEE ; Eun Young KIM ; Hyo Sup SHIM ; Young Joo SUH ; Ha Eun KIM ; Jin Gu LEE ; Jinwook CHOI ; Ju Hyeon LEE ; Chul Hoon KIM ; Moo Suk PARK
Tuberculosis and Respiratory Diseases 2025;88(1):130-137
Background:
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease that culminates in respiratory failure and death due to irreversible scarring of the distal lung. While initially considered a chronic inflammatory disorder, the aberrant function of the alveolar epithelium is now acknowledged as playing a central role in the pathophysiology of IPF. This study aimed to investigate the regenerative capacity of alveolar type 2 (AT2) cells using IPF-derived alveolar organoids and to examine the effects of disease progression on this capacity.
Methods:
Lung tissues from three pneumothorax patients and six IPF patients (early and advanced stages) were obtained through video-assisted thoracoscopic surgery and lung transplantation. HTII-280+ cells were isolated from CD31-CD45-epithelial cell adhesion molecule (EpCAM)+ cells in the distal lungs of IPF and pneumothorax patients using fluorescence-activated cell sorting (FACS) and resuspended in 48-well plates to establish IPF-derived alveolar organoids. Immunostaining was used to verify the presence of AT2 cells.
Results:
FACS sorting yielded approximately 1% of AT2 cells in early IPF tissue, and the number decreased as the disease progressed, in contrast to 2.7% in pneumothorax. Additionally, the cultured organoids in the IPF groups were smaller and less numerous compared to those from pneumothorax patients. The colony forming efficiency decreased as the disease advanced. Immunostaining results showed that the IPF organoids expressed less surfactant protein C (SFTPC) compared to the pneumothorax group and contained keratin 5+ (KRT5+) cells.
Conclusion
This study confirmed that the regenerative capacity of AT2 cells in IPF decreases as the disease progresses, with IPF-derived AT2 cells inherently exhibiting functional abnormalities and altered differentiation plasticity.
2.Feasibility of a Machine Learning Classifier for Predicting Post-Induction Hypotension in Non-Cardiac Surgery
Insun PARK ; Jae Hyon PARK ; Young Hyun KOO ; Chang-Hoon KOO ; Bon-Wook KOO ; Jin-Hee KIM ; Ah-Young OH
Yonsei Medical Journal 2025;66(3):160-171
Purpose:
To develop a machine learning (ML) classifier for predicting post-induction hypotension (PIH) in non-cardiac surgeries.
Materials and Methods:
Preoperative data and early vital signs were obtained from 3669 cases in the VitalDB database, an opensource registry. PIH was defined as sustained mean arterial pressure (MAP) <65 mm Hg within 20 minutes since induction or from induction to incision. Six different ML algorithms were used to create binary classifiers to predict PIH. The primary outcome was the area under the receiver operating characteristic curve (AUROC) of ML classifiers.
Results:
A total of 2321 (63.3%) cases exhibited PIH. Among ML classifiers, the random forest regressor and extremely gradient boosting regressor showed the highest AUROC, both recording a value of 0.772. Excluding these models, the light gradient boosting machine regressor showed the second highest AUROC [0.769; 95% confidence interval (CI), 0.767–0.771], followed by the gradient boosting regressor (0.768; 95% CI, 0.763–0.772), AdaBoost regressor (0.752; 95% CI, 0.743–0.761), and automatic relevance determination regression (0.685; 95% CI, 0.669–0.701). The top three important features were mean diastolic blood pressure (DBP), minimum MAP, and minimum DBP from anesthetic induction to tracheal intubation, and these features were lower in cases with PIH (all p<0.001).
Conclusion
ML classifiers exhibited moderate performance in predicting PIH, and have the potential for real-time prediction.
3.Analysis of Changes in Relative Value Scale and Frequency of Surgery and Procedures in Surgery Departments Over the Past 18 Years: Secondary Publication
Jae Hoon CHO ; Sei Young LEE ; Seung Hoon LEE ; Seog-Kyun MUN ; Jung Hyun CHANG ; Chan-Soon PARK
Korean Journal of Otolaryngology - Head and Neck Surgery 2025;68(2):67-73
Background and Objectives:
The purpose of this study was to compare and analyze the 18- year change in the relative value scale (RVS) in otolaryngology in relation to other surgical departments so as to help make future policy decisions.Subjects and Method Data on RVSs and addition rates, the deparments of main managed care, frequency of practice, and number of specialists were collected for all surgeries and procedures conducted in 2004, 2008, 2013, 2018, and 2022. Among these, an analysis was conducted for nine surgical departments. The number of surgeries and procedure items, the median value of the RVS, and the usage amount (i.e., RVS of all items multiplied by the frequency of surgeries and procedures) were calculated.
Results:
Over the past 18 years, the increase in the number of surgeries, procedure items and RVS in otolaryngology has grown smaller than that in other surgical departments, and the usage has decreased very sharply; in essence, the usage per specialist has actually decreased compared to 18 years ago.
Conclusion
Compared to other departments, RVS in otorhinolaryngology has shown very little change over the past period of 18 years. It is necessary to reasonably increase the currently undervalued RVS in otorhinolaryngology, particularly focusing on surgeries and procedures.
4.Part 1. Current Status of Hearing Loss Patients in Korea Using National Data: National Health Insurance Service- Database, 2010 to 2020
Junhun LEE ; Chul Young YOON ; Jiwon KIM ; In-Ki JIN ; Michelle J. SUH ; Wan-Ho CHO ; Hyo-Jeong LEE ; Seong Jun CHOI ; Dongchul CHA ; Kyung Ho PARK ; Soo Hee OH ; Young Joon SEO ; Tae Hoon KONG
Korean Journal of Otolaryngology - Head and Neck Surgery 2025;68(1):7-18
Background and Objectives:
Hearing loss significantly affects communication, psychosocial well-being, and quality of life. This study analyzes the National Health Insurance Service database to assess the trends and characteristics of hearing loss in South Korea from 2010 to 2020.Subjects and Method The database encompasses 97% of the Korean population, providing comprehensive data on medical history, prescriptions, and health examinations. The analysis used the World Health Organization’s ICD-10 definitions to categorize hearing loss types and examine their prevalence and incidence across various demographics over 11 years.
Results:
There was an overall annual increase of 4.62% in diagnosed cases of hearing loss, with the most significant rise among the elderly. The rate of increase accelerated from 3.32% between 2010 and 2014 to 6.49% between 2014 and 2020, corresponding with the improved hearing aid access facilitated by policy changes. Women showed a slightly higher increase than men. The data also indicated a consistent rise in abnormal hearing test results during health examinations, especially in older adults.
Conclusion
The study highlights an increasing trend in hearing loss diagnoses, driven by an aging population and enhanced detection facilitated by policy changes. These findings emphasize the need for continuous monitoring and targeted health policies to manage hearing loss effectively, offering valuable insights for global health management and policy development.
5.Part 2. Current Status of Hearing Disability and Hearing Rehabilitation Devices in Korea Using National Data: NHIS-Database, 2010 to 2020
Junhun LEE ; Chul Young YOON ; Jiwon KIM ; In-Ki JIN ; Michelle J. SUH ; Wan-Ho CHO ; Hyo-Jeong LEE ; Seong Jun CHOI ; Dongchul CHA ; Kyung Ho PARK ; Soo Hee OH ; Young Joon SEO ; Tae Hoon KONG
Korean Journal of Otolaryngology - Head and Neck Surgery 2025;68(3):94-104
Background and Objectives:
This study aims to analyze trends in hearing disability and the use of hearing rehabilitation devices (hearing aids and cochlear implants) in South Korea over the past 11 years (2010-2020) using data from the National Health Insurance Service (NHIS).Subjects and Method Data were extracted from the NHIS database, covering approximately 97% of the South Korean population. Patients diagnosed with hearing loss were classified using ICD-10 codes. The data were analyzed to determine trends in hearing disability, hearing aid prescriptions, and cochlear implant usage by age, gender, and types and causes of hearing loss.
Results:
The number of hearing disability patients increased from 170900 in 2010 to 362738 in 2020, with an annual growth rate of 7.95%. The highest increase was observed in the ≥60 age group, with an annual growth rate of 11.04%. Hearing aid prescriptions rose from 4966 in 2010 to 11974 in 2020, showing a 10.45% annual increase. Females showed a higher growth rate in both hearing disability and hearing aid prescriptions compared to males. Cochlear implant prescriptions also increased, particularly among older adults.
Conclusion
The study highlights a significant rise in hearing disability and the use of hearing aids and cochlear implants in South Korea, especially among the elderly. The findings underscore the importance of early diagnosis and intervention for hearing loss and the need for policy improvements to enhance accessibility and affordability of hearing rehabilitation services. Additional strategies are needed to ensure appropriate hearing rehabilitation for those not yet receiving adequate care.
6.Radiofrequency Ablation for Recurrent Thyroid Cancers:2025 Korean Society of Thyroid Radiology Guideline
Eun Ju HA ; Min Kyoung LEE ; Jung Hwan BAEK ; Hyun Kyung LIM ; Hye Shin AHN ; Seon Mi BAEK ; Yoon Jung CHOI ; Sae Rom CHUNG ; Ji-hoon KIM ; Jae Ho SHIN ; Ji Ye LEE ; Min Ji HONG ; Hyun Jin KIM ; Leehi JOO ; Soo Yeon HAHN ; So Lyung JUNG ; Chang Yoon LEE ; Jeong Hyun LEE ; Young Hen LEE ; Jeong Seon PARK ; Jung Hee SHIN ; Jin Yong SUNG ; Miyoung CHOI ; Dong Gyu NA ;
Korean Journal of Radiology 2025;26(1):10-28
Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.
7.Prospective Evaluation of Accelerated Brain MRI Using Deep Learning-Based Reconstruction: Simultaneous Application to 2D Spin-Echo and 3D Gradient-Echo Sequences
Kyu Sung CHOI ; Chanrim PARK ; Ji Ye LEE ; Kyung Hoon LEE ; Young Hun JEON ; Inpyeong HWANG ; Roh Eul YOO ; Tae Jin YUN ; Mi Ji LEE ; Keun-Hwa JUNG ; Koung Mi KANG
Korean Journal of Radiology 2025;26(1):54-64
Objective:
To prospectively evaluate the effect of accelerated deep learning-based reconstruction (Accel-DL) on improving brain magnetic resonance imaging (MRI) quality and reducing scan time compared to that in conventional MRI.
Materials and Methods:
This study included 150 participants (51 male; mean age 57.3 ± 16.2 years). Each group of 50 participants was scanned using one of three 3T scanners from three different vendors. Conventional and Accel-DL MRI images were obtained from each participant and compared using 2D T1- and T2-weighted and 3D gradient-echo sequences. Accel-DL acquisition was achieved using optimized scan parameters to reduce the scan time, with the acquired images reconstructed using U-Net-based software to transform low-quality, undersampled k-space data into high-quality images. The scan times of Accel-DL and conventional MRI methods were compared. Four neuroradiologists assessed the overall image quality, structural delineation, and artifacts using Likert scale (5- and 3-point scales). Inter-reader agreement was assessed using Fleiss’ kappa coefficient. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated, and volumetric quantification of regional structures and white matter hyperintensities (WMHs) was performed.
Results:
Accel-DL showed a mean scan time reduction of 39.4% (range, 24.2%–51.3%). Accel-DL improved overall image quality (3.78 ± 0.71 vs. 3.36 ± 0.61, P < 0.001), structure delineation (2.47 ± 0.61 vs. 2.35 ± 0.62, P < 0.001), and artifacts (3.73 ± 0.72 vs. 3.71 ± 0.69, P = 0.016). Inter-reader agreement was fair to substantial (κ = 0.34–0.50). SNR and CNR increased in Accel-DL (82.0 ± 23.1 vs. 31.4 ± 10.8, P = 0.02; 12.4 ± 4.1 vs. 4.4 ± 11.2, P = 0.02). Bland-Altman plots revealed no significant differences in the volumetric measurements of 98.2% of the relevant regions, except in the deep gray matter, including the thalamus. Five of the six lesion categories showed no significant differences in WMH segmentation, except for leukocortical lesions (r = 0.64 ± 0.29).
Conclusion
Accel-DL substantially reduced the scan time and improved the quality of brain MRI in both spin-echo and gradientecho sequences without compromising volumetry, including lesion quantification.
8.Presence of RB1 or Absence of LRP1B Mutation Predicts Poor Overall Survival in Patients with Gastric Neuroendocrine Carcinoma and Mixed Adenoneuroendocrine Carcinoma
In Hye SONG ; Bokyung AHN ; Young Soo PARK ; Deok Hoon KIM ; Seung-Mo HONG
Cancer Research and Treatment 2025;57(2):492-506
Purpose:
Neuroendocrine carcinomas (NECs) of the stomach are extremely rare, but fatal. However, our understanding of the genetic alterations in gastric NECs is limited. We aimed to evaluate genomic and clinicopathological characteristics of gastric NECs and mixed adenoneuroendocrine carcinomas (MANECs).
Materials and Methods:
Fourteen gastric NECs, three gastric MANECs, and 1,381 gastric adenocarcinomas were retrieved from the departmental next-generation sequencing database between 2017 and 2022. Clinicopathological parameters and next-generation sequencing test results were retrospectively collected and reviewed.
Results:
Gastric NECs and MANECs frequently harbored alterations of TP53, RB1, SMARCA4, RICTOR, APC, TOP1, SLX4, EGFR, BRCA2, and TERT. In contrast, gastric adenocarcinomas exhibited alterations of TP53, CDH1, LRP1B, ARID1A, ERBB2, GNAS, CCNE1, NOTCH, and MYC. Mutations of AKT3, RB1, and SLX4; amplification of BRCA2 and RICTOR; and deletion of ADAMTS18, DDX11, KLRC3, KRAS, MAX, NFKBIA, NUDT7, and RB1 were significantly more frequent in gastric NECs and MANECs than in gastric adenocarcinomas. The presence of LRP1B mutation was significantly associated with longer overall survival (OS), whereas RB1 mutation and advanced TNM stage were associated with shorter OS.
Conclusion
We identified frequently mutated genes and potential predictors of survival in patients with gastric NECs and MANECs.
9.The Survival and Financial Benefit of Investigator-Initiated Trials Conducted by Korean Cancer Study Group
Bum Jun KIM ; Chi Hoon MAENG ; Bhumsuk KEAM ; Young-Hyuck IM ; Jungsil RO ; Kyung Hae JUNG ; Seock-Ah IM ; Tae Won KIM ; Jae Lyun LEE ; Dae Seog HEO ; Sang-We KIM ; Keunchil PARK ; Myung-Ju AHN ; Byoung Chul CHO ; Hoon-Kyo KIM ; Yoon-Koo KANG ; Jae Yong CHO ; Hwan Jung YUN ; Byung-Ho NAM ; Dae Young ZANG
Cancer Research and Treatment 2025;57(1):39-46
Purpose:
The Korean Cancer Study Group (KCSG) is a nationwide cancer clinical trial group dedicated to advancing investigator-initiated trials (IITs) by conducting and supporting clinical trials. This study aims to review IITs conducted by KCSG and quantitatively evaluate the survival and financial benefits of IITs for patients.
Materials and Methods:
We reviewed IITs conducted by KCSG from 1998 to 2023, analyzing progression-free survival (PFS) and overall survival (OS) gains for participants. PFS and OS benefits were calculated as the difference in median survival times between the intervention and control groups, multiplied by the number of patients in the intervention group. Financial benefits were assessed based on the cost of investigational products provided.
Results:
From 1998 to 2023, KCSG conducted 310 IITs, with 133 completed and published. Of these, 21 were included in the survival analysis. The analysis revealed that 1,951 patients in the intervention groups gained a total of 2,558.4 months (213.2 years) of PFS and 2,501.6 months (208.5 years) of OS, with median gains of 1.31 months in PFS and 1.58 months in OS per patient. When analyzing only statistically significant results, PFS and OS gain per patients was 1.69 months and 3.02 months, respectively. Investigational drug cost analysis from six available IITs indicated that investigational products provided to 252 patients were valued at 10,400,077,294 won (approximately 8,046,481 US dollars), averaging about 41,270,148 won (approximately 31,930 US dollars) per patient.
Conclusion
Our findings, based on analysis of published research, suggest that IITs conducted by KCSG led to survival benefits for participants and, in some studies, may have provided financial benefits by providing investment drugs.
10.Erratum to ‘Genomic biomarkers to predict response to atezolizumab plus bevacizumab immunotherapy in hepatocellular carcinoma: Insights from the IMbrave150 trial’ Clin Mol Hepatol 2024;30:807-823
Sun Young YIM ; Sung Hwan LEE ; Seung-Woo BAEK ; Bohwa SOHN ; Yun Seong JEONG ; Sang-Hee KANG ; Kena PARK ; Hyewon PARK ; Sunyoung S. LEE ; Ahmed O. KASEB ; Young Nyun PARK ; Sun-Hee LEEM ; Michael A. CURRAN ; Ji Hoon KIM ; Ju-Seog LEE
Clinical and Molecular Hepatology 2025;31(2):669-670

Result Analysis
Print
Save
E-mail