1.The Korean Rectal Cancer Multidisciplinary Committee Clinical Practice Guidelines for Rectal Cancer version 2.0
Hyo Seon RYU ; Hyun Jung KIM ; Dong Hyun KANG ; Yoo-Kang KWAK ; Han Deok KWAK ; Yoon-Hye KWON ; Dalyon KIM ; Baek-Hui KIM ; Jae Hyun KIM ; Ji Hun KIM ; Jin Won KIM ; Tae Hyung KIM ; Hae Young KIM ; Soo Min NAM ; Gyoung Tae NOH ; Jun Woo BONG ; Nak Song SUNG ; Seon Hui SHIN ; Kil-Yong LEE ; Sung Chul LEE ; Sea-Won LEE ; Jung Won LEE ; Jong Min LEE ; Myung Hoon IHN ; Joo Han LIM ; Woong Bae JI ; Dae Hee PYO ; Young Ki HONG ; Jung-Myun KWAK ;
Annals of Coloproctology 2026;42(1):4-33
Rectal cancer, which accounts for approximately 40% of colorectal cancers, remains a major clinical concern. Recent advances in diagnostic imaging, surgical techniques, radiotherapy, and systemic treatment have steadily improved rectal cancer outcomes. Considering this, the Korean Rectal Cancer Multidisciplinary (KRCM) Committee has aimed to provide clinicians and policymakers with up-to-date, evidence-based clinical practice guidelines to support optimal decision-making, reflecting current evidence, the Korean healthcare context, and patient values and preferences. The Clinical Practice Guidelines for Rectal Cancer version 2.0 were developed through multidisciplinary collaboration with related academic societies, building upon and updating the KRCM Clinical Practice Guidelines version 1.0 (titled “Multidisciplinary guidelines for the management of rectal cancer”). These consensus guidelines of the KRCM were established based on a comprehensive literature review, evidence synthesis, with recommendation development guided by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and consideration of applicability in real-world clinical practice under the national health insurance system. Each recommendation has been presented with its strength and level of evidence.
2.High-Resolution Chromosomal Microarray with Diagnostic Potential for Detecting Exon-Level Copy Number Variations Using Targeted and Non-targeted Approaches
Yeseul KIM ; Jee-Soo LEE ; Boram KIM ; Man Jin KIM ; Sung Im CHO ; Seung Won CHAE ; Ho Seob SHIN ; Hoyeon LEE ; Ji Yeon KIM ; Moon-Woo SEONG
Annals of Laboratory Medicine 2026;46(2):190-199
Background:
Copy number variations (CNVs) play an important role in human genetic disorders. Detection of exon-level CNVs is crucial for accurate clinical diagnosis. The CytoScan XON Array, a high-resolution microarray, was recently developed to detect exonic CNVs of various genes.
Methods:
We evaluated the clinical performance of the CytoScan XON Array using 59 patient samples with previously identified CNVs, confirmed via methods including multiple ligation-dependent probe amplification (MLPA), gene-dose PCR, and mRNA assay. Concordance between CytoScan XON and orthogonal methods was evaluated in target regions, and diagnostic utility was compared with that of genome sequencing (GS)-based CNV calling tools through analysis of false-positive CNVs in non-target genomic regions.
Results:
For target regions, the CytoScan XON Array achieved concordance rates of 89.8% and 92.5% at the exon and gene levels, respectively, for all CNV calls. Concordance was higher for multi-exon CNVs (100%) than that for single-exon CNVs (82.6%, P = 0.03). For non-target regions, false-positive CNV calls were reduced to fewer than 0.01 per gene per person through filtering strategies. The array exhibited false-positive detection rates within dosage-sensitive genes comparable with those of GS-based tools.
Conclusions
The CytoScan XON Array, a reliable tool for detecting exon-level CNVs in target regions, can serve as a complementary approach to GS-based CNV calling tools for genome-wide CNV screening with high resolution. However, its performance for single-exon CNVs requires further optimization. Cross-validation with GS-based CNV calling tools is recommended to improve diagnostic accuracy.
3.Molecular and Phenotypic Characterization of Fluid-Derived Patient-Derived Cell and Organoid Models in Advanced Gastric Cancer
Ye Jin MOON ; Woo Sun KWON ; Chan Hee PARK ; Jinsoo JANG ; Juin PARK ; Byeong Gyu YOON ; Han Byeol MUN ; Namju KIM ; Choong-kun LEE ; Hei Cheul JEUNG ; Su-Jin SHIN ; Tae Soo KIM ; Sun Young RHA
Journal of Gastric Cancer 2026;26(2):260-278
Purpose:
Patient-derived cells (PDCs) and patient-derived organoids (PDOs) are complementary preclinical models widely used in translational cancer research. However, their molecular and functional differences have not been systematically characterized. This study established and analyzed paired PDC and PDO models derived from the same gastric cancer ascites to delineate platform-dependent molecular and functional profiles.
Materials and Methods:
Malignant ascites or pleural fluid obtained from 6 patients with advanced gastric cancer were used to establish paired PDC and PDO models. All pairs underwent comprehensive multi-omics profiling, integrating genomic, transcriptomic, and proteomic data. Phenotypic characterization included morphological, histological, proliferative, and cell cycle analyses. Drug sensitivity assays were performed using 4 chemotherapeutic agents commonly used to treat gastric cancer.
Results:
The 6 paired PDC and PDO models exhibited distinct morphological characteristics.Whole-genome analyses demonstrated high concordance among primary tumors, PDCs, and PDOs, confirming tumor representation across platforms. Multi-omics profiling identified platform-dependent molecular signatures; PDOs were enriched for extracellular matrix remodeling and stemness, whereas PDCs displayed proliferation- and immune-related signatures. Clinically relevant biomarkers, including HER2 and MET alterations, were concordant with primary tumors. Notably, drug responses differed between platforms and patients, indicating platform-dependent and patient-specific chemosensitivity.
Conclusions
Paired PDC and PDO models derived from the same patients preserved core patient-specific tumor characteristics while exhibiting distinct molecular and functional profiles. These findings underscore the culture platform as a critical determinant of experimental outcomes and therapeutic responses. Therefore, careful selection of an appropriate preclinical model is essential to accurately address biological questions and optimize precision oncology strategies.
4.Lateral Closing Wedge Supramalleolar Osteotomy with Inframalleolar Correction as a Joint-Preserving Procedure for Valgus Ankle Osteoarthritis: A Case Report
Ju Hwan PARK ; Jin Soo SUH ; Ji-Ye KIM ; Jun Young CHOI
Journal of Korean Foot and Ankle Society 2026;30(2):73-79
A medial closing wedge supramalleolar osteotomy, along with corrections for pes plano-valgus, including medial displacement calcaneal osteotomy, and deltoid ligament repair or reconstruction, is most commonly considered for the joint-preserving surgery of valgus ankle arthritis. In cases of ‘opposing coronal plane deformities,’ however, where the tibial plafond is varus-aligned to the long axis of the tibia and the ground, while the talus is conversely valgus-aligned, medial closing wedge supramalleolar osteotomy may paradoxically risk exacerbating the valgus ankle arthritis. This paper reports the radiological and clinical outcomes of an otherwise healthy, physically active 55-year-old male patient with valgus ankle arthritis and opposing coronal-plane deformities, along with a literature review. The patient underwent joint-preserving surgery consisting of lateral closing wedge supramalleolar osteotomy, fibular osteotomy, medial displacement calcaneal osteotomy, and deltoid ligament augmentation with suture tape. This paper discusses the critical considerations and surgical precautions necessary when deciding on joint-preserving procedures for valgus ankle arthritis.
5.Changes in Esophageal Transit Scintigraphy After Peroral Endoscopic Myotomy in Patients With Achalasia
Young Hoon YOUN ; Kyung Soo KIM ; Yeon Jin JE ; Jae-Hoon LEE ; Young Hoon RYU ; Hyojin PARK
Journal of Neurogastroenterology and Motility 2026;32(1):30-34
Background/Aims:
Esophageal transit scintigraphy is a non-invasive nuclear medicine imaging modality for people with esophageal transit problems. In particular, changes in esophageal motor function can be evaluated non-invasively before and after the treatment in patients undergoing peroral endoscopic myotomy (POEM) for achalasia. This study compared the changes in several parameters of esophageal transit and manometry in patients with achalasia who underwent POEM.
Methods:
This study retrospectively analyzed prospectively collected data from POEM participants. We included 38 patients with achalasia who underwent high-resolution manometry and esophageal transit scintigraphy before POEM and after POEM from 2016 to 2023.
Results:
All patients had clinical treatment successfully (Eckardt score < 3). Lower esophageal sphincter (LES) pressures were significantly reduced after POEM, including basal resting LES pressure and integrated relaxation pressure (P < 0.001).Esophageal emptying, as assessed by the residual fraction of retained radioactivity at 10 seconds after isotope ingestion, improved from 54.3% to 27.3% (P < 0.001). Analysis of the change in time-to-peak on the time-radioactivity curve showed that it shortened significantly in the upper and middle portions of the esophagus (P < 0.05) but not in the lower portion.The Eckardt symptom score significantly correlated with pre-POEM integrated relaxation pressure (P < 0.05). Post-POEM, the symptom score significantly correlated with time-to-peak of the upper portion of the esophagus (P < 0.05).
Conclusions
Patients with achalasia who received POEM showed improved not only manometric LES parameters but also esophageal transit. Analysis of the radiation curve’s time-to-peak showed that improved retention in the upper portion is an indicator of symptoms improvement in patients who underwent POEM.
6.National Trends in Healthcare Quality in Korea: A Multidimensional Assessment Using OECD Health Care Quality Indicators (2008–2023)
Hyejin LEE ; Soo-Hee HWANG ; Sang-A CHO ; Hyemin JUNG ; Youngs CHANG ; Jieun YUN ; Sanghyun CHO ; Un-Na KIM ; Hye Yeon KOO ; Eun Byul CHO ; Do Hee KIM ; Jin Yong LEE
Journal of Preventive Medicine and Public Health 2026;59(3):225-238
Objectives:
Assessing healthcare quality at the national level is essential for evaluating health system performance and identifying areas requiring improvement. This study examined long-term trends in healthcare quality in Korea from 2008 to 2023 using internationally comparable indicators.
Methods:
We conducted a trend analysis of healthcare quality in Korea using the Organization for Economic Cooperation and Development (OECD) Health Care Quality and Outcomes framework and quality indicators. Indicators across multiple domains, including acute care, primary care, prescribing in primary care, mental healthcare, and patient experiences, were analyzed and compared with OECD averages.
Results:
Healthcare quality in Korea improved across several domains. Thirty-day mortality for acute myocardial infarction decreased from 14.2% in 2008 to 10.2% in 2023, while mortality for ischemic stroke declined from 8.7% to 5.5%. Avoidable hospitalizations decreased substantially, with hospitalizations for chronic obstructive pulmonary disease declining by 59.7%. The proportion of patients with diabetes receiving cholesterol-lowering treatment increased from 44.1% to 82.5%. However, the proportion of broad-spectrum antibiotic prescriptions remained substantially higher than the OECD average (40.3 vs. 15.5%). In mental healthcare, excess mortality ratios increased from 4.3 in 2010 to 4.9 in 2023 for schizophrenia and from 3.5 to 4.3 for bipolar disorder, while post-discharge suicide rates showed little improvement. Patient experience indicators related to patient-physician communication improved and approached OECD averages.
Conclusions
Healthcare quality in Korea improved substantially between 2008 and 2023, particularly in acute care outcomes and chronic disease management. However, persistent challenges remain in areas such as antibiotic use, polypharmacy, and mental healthcare. These findings provide internationally comparable evidence to inform future health policy and healthcare quality improvement efforts.
7.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.
8.Ultrasound Imaging Features Associated With Neoplastic Gallbladder Polyps: A Systematic Review and Meta-Analysis
Sunyoung LEE ; Won CHANG ; Yeun-Yoon KIM ; Jin Young PARK ; Sun Kyung JEON ; Jeong Eun LEE ; Jeongin YOO ; Seungchul HAN ; So Hyun PARK ; Jae Hyun KIM ; Hyo Jung PARK ; Hyun-Soo ZHANG ; Jeong Hee YOON
Korean Journal of Radiology 2026;27(4):332-343
Objective:
Although most gallbladder polyps are benign, some neoplastic polyps may be malignant or may serve as precursors to malignancy. Distinguishing neoplastic and non-neoplastic polyps using imaging examinations remains a major challenge.This meta-analysis aimed to identify the ultrasound (US) features that are significantly associated with neoplastic polyps.
Materials and Methods:
The MEDLINE, EMBASE, Cochrane, and KoreaMed databases were searched for articles published up to August 31, 2025. Bivariate random-effects models were used to calculate the meta-analytic pooled diagnostic odds ratios (DORs), sensitivities, and specificities, along with their 95% confidence intervals (CIs), for each US imaging feature in the diagnosis of neoplastic polyps.
Results:
Thirty studies evaluating 8,953 patients, including 1,216 (13.6%) patients with neoplastic polyps, were included.Among the nine evaluated US imaging features, namely, size ≥10 mm, sessile morphology, single polyp, coexisting gallstones, hypoechogenicity, heterogeneous echogenicity, gallbladder wall thickening (GBWT), absence of hyperechoic spot, and vascularity, eight were significantly associated with neoplastic polyps: size ≥10 mm (DOR: 6.23 [95% CI: 1.86– 20.90]), sessile morphology (DOR: 3.54 [1.93–5.97]), single polyp (DOR: 2.21 [1.76–2.74]), coexisting gallstones (DOR:1.86 [1.29–2.60]), hypoechogenicity (DOR: 3.55 [1.47–7.30]), GBWT (DOR: 9.38 [1.47–32.20]), absence of hyperechoic spots (DOR: 4.23 [2.46–6.83]), and vascularity (DOR: 9.72 [5.81–15.30]). Of these, size ≥10 mm demonstrated the highest pooled sensitivity (0.79 [95% CI: 0.68–0.87]), whereas hypoechogenicity showed the highest pooled specificity (0.93 [95% CI: 0.82–0.98]).
Conclusion
Eight US imaging features (size ≥10 mm, sessile morphology, single polyp, coexisting gallstones, hypoechogenicity, GBWT, absence of hyperechoic spots, and vascularity) were significantly associated with the presence of neoplastic polyps.These features may facilitate the management of gallbladder polyps.
9.Association of Breast Tissue Composition on Preoperative Automated Breast Ultrasound With Accuracy of Cancer Multiplicity Evaluation and Recurrence-Free Survival in Patients With Early-Stage Breast Cancer
Myoung Kyoung KIM ; Haejung KIM ; Sun-Young BAEK ; Eun Young KO ; Boo-Kyung HAN ; Eun Sook KO ; Jeongmin LEE ; Nami CHOI ; Jin CHUNG ; Ji Soo CHOI
Korean Journal of Radiology 2026;27(2):97-110
Objective:
To investigate whether breast tissue composition on preoperative automated breast ultrasound (ABUS) is associated with the accuracy of cancer multiplicity evaluation and postoperative recurrence-free survival (RFS) in patients with early-stage breast cancer.
Materials and Methods:
This retrospective analysis included women with early-stage breast cancer (clinical Tis, T1–2/N0) who underwent ABUS and digital mammography (DM) between October 2019 and April 2021. Tissue composition on ABUS was assessed using the Breast Imaging Reporting and Data System background echotexture (BE) (homogeneous-fat, homogeneous-fibroglandular, or heterogeneous). In a subgroup of patients with mammographically dense breasts, the glandular tissue component (GTC) on ABUS were further stratified into high (moderate or marked) or low (minimal or mild).Multivariable logistic and Cox regression analyses were used to identify factors associated with accurate cancer multiplicity categorization (unifocal, multifocal/multicentric, or bilateral) using ABUS + DM, and with RFS, respectively.
Results:
Among 409 women (mean age ± standard deviation, 50.2 ± 8.7 years), ABUS combined with DM yielded accurate cancer multiplicity categorization in 368 patients (90.0%). Neither BE nor GTC on ABUS affected the accuracy of categorization when ABUS was combined with DM. Over a median postoperative follow-up of 3.5 years, 11 recurrences occurred. Heterogeneous BE on ABUS (hazard ratio [HR] 11.24 [95% confidence interval [CI]: 2.82–44.92]; P = 0.001), BRCA mutation (HR 15.94 [2.47–102.97]; P = 0.004), and pathologic index cancer size (HR per 1-cm increase 1.91 [1.13–3.23];P = 0.02) was independently associated with RFS. In patients with dense breasts, heterogeneous BE (HR 14.17 [95% CI:2.69–74.60]; P = 0.002) and high GTC (HR 10.32 [2.35–45.28]; P = 0.002) on ABUS, BRCA mutation (HR 24.34 [2.75– 215.06]; P = 0.004), and pathologic cancer size (HR per 1-cm increase 2.62 [1.50–4.59]; P = 0.001) was independently associated with RFS.
Conclusion
In patients with early-stage breast cancer, heterogeneous BE and high GTC on preoperative ABUS, along with larger cancer size and BRCA mutation, was associated with worse RFS. However, BE and GTC did not affect cancer multiplicity evaluation when ABUS was used in combination with DM.
10.Development of an artificial intelligence-based prediction platform for early recurrence of resectable pancreatic cancer after curative surgery–toward future use as an indication for neoadjuvant treatment: a retrospective multicenter cohort study
So Jeong YOON ; Sung Hyun KIM ; Hongbeom KIM ; Sang Hyun SHIN ; Jin Seok HEO ; Seung Soo HONG ; Chang Moo KANG ; Kyung Sik KIM ; Ho Kyoung HWANG ; In Woong HAN
Annals of Surgical Treatment and Research 2026;110(2):76-83
Purpose:
Neoadjuvant treatment (NAT) is now the standard for borderline resectable pancreatic cancer (RPC) and is being considered for RPC. Early recurrence after curative surgery in RPC is often seen as a treatment failure, prompting considerations for NAT. Our goal was to develop an artificial intelligence (AI)-based predictive model utilizing preoperatively available factors to forecast early recurrences of resected RPC.
Methods:
This study included 469 patients who underwent surgery for RPC between 2011 and 2019. Clinicopathologic and oncologic data were retrospectively reviewed. Preoperative variables, including laboratory data and imaging findings, were collected. Early recurrence was defined as recurrence occurring within a year after surgery. Deep neural networks were then used to select variables by assessing their importance. A new model predicting early recurrence of RPC was subsequently developed.
Results:
Of the patients evaluated, 199 (42.4%) experienced early recurrence. The predictive model included 14 preoperative variables: CA 19-9, preoperative pancreatitis, serum albumin, platelet count, lymphocyte count, the American Society of Anesthesiologists physical status classification, tumor size, monocyte count, age, body mass index, CRP, hemoglobin, WBC count, and CEA. The area under the curve for the model was 0.786 in the training set and 0.734 in the test set.
Conclusion
We developed an AI-based model to predict the early recurrence of RPC using preoperative parameters. By identifying patients at risk of early recurrence, optimal individualized treatments such as NAT can be considered. Future prospective studies are crucial to establish clear indications for NAT in RPC.

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