Purpose: To report the clinical utility of the Barrett True-K formula in predicting multifocal intraocular lens (IOL) power in a patient with corneal deformation caused by radial keratotomy (RK), where postoperative refractive power prediction is challenging.Case summary: A 61-year-old male who underwent RK 30 years ago presented for cataract surgery. Slit-lamp examination showed eight RK incisions in each eye. Refractive error was +3.25 D sph; -1.75 D cyl, axis 70 in the right eye and +2.75 D sph; -1.00 D cyl, axis 110 in the left. Uncorrected visual acuity was 0.32 in the right eye and 0.63 in the left. IOL power was calculated using the Barrett True-K formula on the IOLMaster 700, with a target refraction of -0.25 D, and a multifocal IOL was implanted. Six months after cataract surgery, both eyes achieved a fraction close to emmetropia, with best corrected visual acuity of 0.63 in the right eye and 1.0 in the left. No significant refractive shifts or other complications were observed during surgery or 6-month follow-up. Conclusions The Barrett True-K formula, which measures the actual corneal refractive power to compensate for corneal deformation, is expected to be clinically useful for multifocal IOL implantation during cataract surgery in eyes after RK.

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.

Purpose: Alectinib has been approved for anaplastic lymphoma kinase (ALK)–positive non–small cell lung cancer (NSCLC) at 300 mg twice daily in Japan, lower than global standard of 600 mg twice daily. This study evaluated the clinical relevance of the reduced dose by comparing outcomes between the two doses. Materials and Methods: This study included patients with advanced ALK-positive NSCLC who received alectinib at Samsung Medical Center, Korea. The progression-free survival (PFS), overall survival, cumulative incidence of central nervous system (CNS) progression, and safety profiles were retrospectively reviewed and compared. Results: Among 306 patients, 32 and 274 received alectinib at either 300 or 600 mg twice daily, respectively. The 300 mg group showed a slight but not significant advantage in PFS (hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.44 to 1.51; p=0.51) and overall survival (HR, 0.51; 95% CI, 0.20 to 1.21; p=0.13). Superior outcome with 300 mg was remarkable in patients with lower body weight (≤ 60 kg), but diminished in patients with higher body weights. Patients with baseline brain metastasis in the 300 mg group exhibited a slight increase in incidence of CNS failure (HR, 1.76; 95% CI, 0.53 to 5.8; p=0.36). Although the safety profiles were mostly mild, adverse events were more frequent in the 600 mg group, 50% of which requiring dose reduction. Conclusion Alectinib at 300 mg twice daily seems an acceptable dose in East Asians with ALK-positive NSCLC. Notably, our data favor 300 mg twice daily in patients with lower body weight and no baseline brain metastasis, considering the more tolerable safety profiles and the potential to reduce medical costs.

Purpose: To develop the 2025 update to the Korean colorectal cancer (CRC) screening guidelines by systematically evaluating recent evidence, integrating domestic data, and addressing changes since the 2015 guideline revision, thereby providing an evidence-based standard for clinicians and policymakers. Methods: A multidisciplinary committee developed the guidelines using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. The process included formulation of three key questions addressing screening efficacy, diagnostic accuracy, and optimal screening age and interval. A systematic review of international guidelines and primary literature was conducted, yielding 327 eligible studies. In addition, a utility-based analysis using a Markov model was performed to determine optimal screening ages and intervals. Results: The evidence synthesis identified high-certainty evidence supporting the use of the fecal immunochemical test (FIT) for reducing CRC mortality and moderate-certainty evidence for colonoscopy. Evidence for computed tomographic colonography (CTC) and stool DNA testing was rated as very low certainty. Based on the evidence review and cost-utility analysis, the committee conditionally recommends CRC screening for asymptomatic, average-risk adults aged 45–74 years using either colonoscopy every 10 years or FIT every 1–2 years. CTC and stool DNA testing were not recommended owing to insufficient evidence. Conclusion The 2025 Korean Guidelines for Colorectal Cancer Screening present updated, evidence-based recommendations tailored to the domestic healthcare context. By conditionally endorsing both colonoscopy and FIT for individuals aged 45–74 years, these guidelines aim to improve population-level screening effectiveness and reduce the burden of CRC in South Korea.

Background: and Purpose Intraoperative visual evoked potential (VEP) monitoring has been studied mainly in pituitary adenoma, while its role in nonpituitary suprasellar tumors has remained unclear. This study evaluated the predictive usefulness of intraoperative VEP monitoring during endoscopic endonasal surgery (EES) and aimed to identify optimal alarm criteria for visual outcomes. Methods: We retrospectively analyzed a cohort of 87 patients who underwent EES with intraoperative VEP monitoring between April 2021 and September 2023. Visual outcomes were evaluated preoperatively and at short-term (≤3 months) and long-term (12 months) followups, with visual deterioration at these time points defined as worsening of either visual acuity or the visual field. Reductions in the VEP amplitude were quantified using both the maximum intraoperative decrease and the final amplitude after recovery. Receiver operating characteristic (ROC) curve analyses were performed to identify the optimal alarm thresholds, and the sensitivity, specificity, positive predictive value, and negative predictive value were calculated for short-term and long-term visual deteriorations. Results: Short-term and long-term visual deteriorations were detected in 12 (9.2%) and 5 (3.8%) of the 130 analyzed eyes, respectively. ROC curve analyses identified ≥40% and ≥30% reductions in the N75–P100 amplitude as optimal alarm criteria for short-term and long-term visual deteriorations, respectively. A 30% reduction without intraoperative recovery demonstrated markedly higher sensitivity than the conventional 50% alarm threshold for short-term (58.3% vs. 33.3%) and long-term (80.0% vs. 20.0%) outcomes, while maintaining acceptable specificity (82.2% and 80.8%, respectively). Conclusions A 30% reduction in amplitude represents a more-sensitive and clinically relevant alarm threshold than a 50% reduction for intraoperative VEP monitoring during EES for nonpituitary suprasellar tumors. Incorporating both the magnitude and recovery pattern of VEP amplitude changes may improve the accuracy of predictions of long-term visual deterioration. However, the potential for false positives warrants cautious interpretation, and further studies are needed to validate the impact of intraoperative VEP monitoring on visual outcomes.

Objective: Recently, various mental health promotion programs using virtual reality (VR) technology have been tried in the psychiatric field. Considering the importance of mental health in pregnant women, VR-assisted mental health promotion programs for pregnant women are needed to be developed. This study aimed to prospectively investigate the efficacy of a VR-assisted mental health promotion program for pregnant women. Methods: Fifty-five pregnant women were participated in this study. Mental health states such as depression, anxiety, perceived stress, and quality of life were assessed by Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), Perceived Stress Scale, and World Health Organization Quality of Life Scale Abbreviated Version (WHOQOL-BREF) before and after using VR program treatment. Based on the mental health types of pregnant women classified by cluster analysis, the effects of the VR program were analyzed by paired t test and Wilcoxon signed rank test. Results: The VR program significantly reduced PHQ-9 (p = 0.033) and GAD-7 (p = 0.046) scores, and significantly increased WHOQOL-BREF (p = 0.026) score of the participants. Additionally, when classifying the mental health types of pregnant women, the VR program was significantly effective to improve depression, anxiety, and quality of life in the most severe group based on the cluster analysis. Conclusion The results of this study suggest that VR program may be effective to improve the mental health of pregnant women. Particularly, VR programs for the high-risk group of depression might be the most effective. Therefore, VR-assisted mental health promotion programs could be useful for managing the mental health in pregnant women.

Background/Aims: The Korean guidelines for Helicobacter pylori treatment were revised in 2020, however, the extent of adherence to these guidelines in clinical practice remains unclear. Herein, we initiated a prospective, nationwide, multicenter registry study in 2021 to evaluate the current management of H.pylori infection in Korea. Methods: This interim report describes the adherence to the revised guidelines and their impact on firstline eradication rates. Data on patient demographics, diagnoses, treatments, and eradication outcomes were collected using a web-based electronic case report form. Results: A total of 7,261 patients from 66 hospitals who received first-line treatment were analyzed.The modified intention-to-treat eradication rate for first-line treatment was 81.0%, with 80.4% of the prescriptions adhering to the revised guidelines. The most commonly prescribed regimen was the 14-day clarithromycin-based triple therapy (CTT; 42.0%), followed by tailored therapy (TT; 21.2%), 7-day CTT (14.1%), and 10-day concomitant therapy (CT; 10.1%). Time-trend analysis demonstrated significant increases in guideline adherence and the use of 10-day CT and TT, along with a decrease in the use of 7-day CTT (all p<0.001). Multivariate logistic regression analysis revealed that guideline adherence was significantly associated with first-line eradication success (odds ratio, 2.03; 95% confidence interval, 1.61 to 2.56; p<0.001). Conclusions The revised guidelines for the treatment of H. pylori infection have been increasingly adopted in routine clinical practice in Korea, which may have contributed to improved first-line eradication rates. Notably, the 14-day CTT, 10-day CT, and TT regimens are emerging as the preferred first-line treatment options among Korean physicians.

Background/Aims: The study investigated the incidence, risk factors, and clinical outcomes of chronic antibiotic-refractory pouchitis (CARP) in Korean patients with ulcerative colitis (UC). Methods: This single-center retrospective study included patients with UC who underwent total proctocolectomy with ileal pouch-anal anastomosis at the Asan Medical Center in Korea between January 1987 and December 2022. The primary outcomes were endoscopic remission and pouch failure. The Cox’s proportional hazard model was used to identify the risk factors for CARP. Results: The clinical data of 232 patients were analyzed. The most common cause of surgery was steroid refractoriness (50.9%), followed by dysplasia/colorectal cancer (26.7%). Among 74 patients (31.9%) with chronic pouchitis (CP), 31 (13.4%) had CARP, and 43 (18.5%) had chronic antibiotic-dependent pouchitis (CADP). The most frequent endoscopic phenotype was focal inflammation of the pouch (CP, 47.3%; CARP, 35.5%; CADP, 55.8%). Patients with CARP were less likely to use concomitant probiotics than patients with CADP (29.0% vs 72.1%, p<0.01). The endoscopic remission rate of CP, CARP, and CADP was 14.9%, 9.7%, and 18.6%, respectively.The pouch failure rate associated with CP, CARP, and CADP was 13.5%, 16.1%, and 11.6%, respectively. Current smoking status (adjusted hazard ratio [aHR], 2.96; 95% confidence interval [CI], 1.27 to 6.90; p=0.01) and previous use of biologics/small molecules (aHR, 2.40; 95% CI, 1.05 to 5.53; p=0.04) were significantly associated with CARP development. Conclusions UC patients who were current smokers and previously used biologics/small molecules had a higher risk of developing CARP. Concomitant use of probiotics was less likely to be associated with CARP development.

Purpose: Considering the high disease burden and unique features of Asian patients with breast cancer (BC), it is essential to have a comprehensive view of genetic characteristics in this population. An institutional targeted sequencing platform was developed through the Korea Research-Driven Hospitals project and was incorporated into clinical practice. This study explores the use of targeted next-generation sequencing (NGS) and its outcomes in patients with advanced/metastatic BC in the real world. Materials and Methods: We reviewed the results of NGS tests administered to BC patients using a customized sequencing platform—FiRST Cancer Panel (FCP)—over 7 years. We systematically described clinical translation of FCP for precise diagnostics, personalized therapeutic strategies, and unraveling disease pathogenesis. Results: NGS tests were conducted on 548 samples from 522 patients with BC. Ninety-seven point six percentage of tested samples harbored at least one pathogenic alteration. The common alterations included mutations in TP53 (56.2%), PIK3CA (31.2%), GATA3 (13.8%), BRCA2 (10.2%), and amplifications of CCND1 (10.8%), FGF19 (10.0%), and ERBB2 (9.5%). NGS analysis of ERBB2 amplification correlated well with human epidermal growth factor receptor 2 immunohistochemistry and in situ hybridization. RNA panel analyses found potentially actionable and prognostic fusion genes. FCP effectively screened for potentially germline pathogenic/likely pathogenic mutation. Ten point three percent of BC patients received matched therapy guided by NGS, resulting in a significant overall survival advantage (p=0.022), especially for metastatic BCs. Conclusion Clinical NGS provided multifaceted benefits, deepening our understanding of the disease, improving diagnostic precision, and paving the way for targeted therapies. The concrete advantages of FCP highlight the importance of multi-gene testing for BC, especially for metastatic conditions.

Objectives: This study examined the psychosocial factors that influence the continuation of clozapine use among individuals with schizophrenia. This examination was conducted through indepth qualitative interviews. Methods: Thirty-one adults diagnosed with schizophrenia (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) who had been taking Clozapine ® for at least 3 months were interviewed. Data were collected from May to October 2024 and analyzed using Braun and Clarke’s thematic analysis. Results: Two overarching themes emerged: 1) transformation of perceptions and engagement with treatment, including initial resistance stemming from severe symptoms and lack of insight, experiences of coercive interventions, rebuilding trust in the mental health system, and evolving attitudes toward psychiatric medications; and 2) personal recovery and social support, encompassing coping with side effects, recognizing symptom improvement and renewed hope, and the pivotal roles of family and therapeutic alliance. Trust in healthcare providers and emotional support from family were central to sustained adherence to clozapine. Conclusion Sustained clozapine use in schizophrenia patients is influenced by intertwined psychological, relational, and contextual factors. Acceptance of treatment was supported by symptom improvement, family support, and trust in healthcare providers. These elements contributed to medication adherence and broader functional recovery. A person-centered, integrated approach is essential to promote continued use and long-term outcomes.