Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.

Background: Healthcare-associated infections impose a significant burden on antibiotic usage, healthcare expenditures, and morbidity. Therefore, it is crucial to revise policies to minimize such losses. This nationwide survey aimed to evaluate infection prevention and control (IPC) components in healthcare facilities and encourage improvements in acute care hospitals with inadequate infection prevention settings. This study aims to enhance the infection control capabilities of healthcare facilities. Methods: From December 27, 2021, to May 13, 2022, we conducted a survey of 1,767 acute care hospitals in the Republic of Korea. A survey was conducted to evaluate the infection control components in 1,767 acute care hospitals. Infection control officers provided direct responses to a systematically developed questionnaire. Subsequently, 10% of the respondents were randomly selected for the site investigation. Results: Overall, 1,197 (67.7%) hospitals responded to the online survey. On-site investigations were conducted at 125 hospitals. Hospitals with ≥ 150 beds are advised to have an IPC team under Article 3 of the Medical Service Act; however, only 87.0% (598/687) of hospitals with ≥ 100 beds had one. Conversely, 22.7% (116/510) of hospitals with < 100 beds had an IPC team. Regulations for hand hygiene, waste management, healthcare worker protection and safety, environmental cleaning, standard precautions, and prevention of the transmission of multidrug-resistant pathogens were present in 84.2%, 80.1%, 77.4%, 76.2%, 75.8%, and 63.5% of the hospitals, respectively. Hospitals with < 100 beds had low availability of all categories of standard operating procedures. Conclusion This study is the first national survey of acute care hospitals in the Republic of Korea. The data presented in the current study will improve the understanding of IPC status and will help establish a survey system. Our survey provides a basis for improving policies related to IPC in healthcare facilities.

Background: Although an appropriate weight management strategy is essential for obese individuals, weight loss can have adverse effects on bone mineral density (BMD). We conducted a systematic review of randomized controlled trials to evaluate changes in BMD after the implementation of various weight loss strategies. Methods: The PubMed, Embase, Web of Science, and Cochrane Library databases were searched to find articles published from database inception until June 2023. Randomized controlled trials of various treatments for obese patients that reported changes in BMD were selected. The primary outcome was BMD of the whole body, lumbar spine, and total hip, measured using dual X-ray absorptiometry. Results: Eighteen randomized controlled trials involving 2,510 participants with obesity were included in the analysis. At follow-up examination, the BMD of the lumbar spine decreased significantly after metabolic surgery (mean difference [MD]= –0.40 g/cm2 ; 95% confidence interval [CI], –0.73 to –0.07; I2 = 0%); lifestyle and pharmacological interventions did not result in a significant decrease in BMD at any location. Metabolic surgery also produced the most substantial difference in weight, with an MD of –3.14 (95% CI, –3.82 to –2.47). Conclusion This meta-analysis is the first to examine the effects of all categories of anti-obesity strategies, including the use of anti-obesity medications, on BMD. Bariatric metabolic surgery can have adverse effects on BMD. Moreover, medications can be used as a treatment for weight loss without compromising bone quality.

Background: Epidermal growth factor receptor (EGFR) gene mutation testing is crucial for the administration of tyrosine kinase inhibitors to treat non–small cell lung cancer. In addition to traditional tissue-based tests, liquid biopsies using plasma are increasingly utilized, particularly for detecting T790M mutations. This study compared tissue- and plasma-based EGFR testing methods. Methods: A total of 248 patients were tested for EGFR mutations using tissue and plasma samples from 2018 to 2023 at Pusan National University Yangsan Hospital. Tissue tests were performed using PANAmutyper, and plasma tests were performed using the Cobas EGFR Mutation Test v2. Results: All 248 patients underwent tissue-based EGFR testing, and 245 (98.8%) showed positive results. Of the 408 plasma tests, 237 (58.1%) were positive. For the T790M mutation, tissue biopsies were performed 87 times in 69 patients, and 30 positive cases (38.6%) were detected. Plasma testing for the T790M mutation was conducted 333 times in 207 patients, yielding 62 positive results (18.6%). Of these, 57 (27.5%) were confirmed to have the mutation via plasma testing. Combined tissue and plasma tests for the T790M mutation were positive in nine patients (13.4%), while 17 (25.4%) were positive in tissue only and 12 (17.9%) in plasma only. This mutation was not detected in 28 patients (43.3%). Conclusions Although the tissue- and plasma-based tests showed a sensitivity of 37.3% and 32.8%, respectively, combined testing increased the detection rate to 56.7%. Thus, neither test demonstrated superiority, rather, they were complementary.

Objectives: To evaluate the factors that influence the survival of dental implants and marginal bone loss (MBL) in patients taking osteoporosis or osteopenia medication. Materials and Methods: This study included patients who underwent dental implant treatment after taking medication for osteoporosis or osteopenia. Electronic medical records were used to collect data of patient age, sex, age at osteoporosis or osteopenia diagnosis, types of medications, age at medication initiation, duration of medication before implant surgery, whether the medication was paused before surgery, paused duration of medication, implant survival status, and MBL before and after prosthetic treatment. Firth’s logistic regression was used to analyze the relationships between each variable and implant survival as well as between MBL before and after prosthetic treatment. Results: Of the 267 patients, 111 with 209 implants were included in the study. The mean observation period was 57.9 months. The survival rate was 92.8% at the patient level and 96.2% at the implant level. No significant associations were found between implant survival and any of the variablesexamined. MBL before prosthetic treatment was significantly associated with use of receptor activator of nuclear factor-κB ligand (RANKL) inhibitors(P=0.032) and bone formation stimulators (P=0.022). Comparing the concurrent and single use of bisphosphonates and RANKL inhibitors, only the use of RANKL inhibitors alone was significantly associated with MBL before prosthetic treatment (P=0.039). MBL after prosthetic treatment was significantly associated with injection method among the routes of drug administration (P=0.011). Conclusion The implant survival rate in patients undergoing medical treatment for osteoporosis or osteopenia was comparable to the general implant survival rate. MBL before prosthetic treatment was associated with type of anti-osteoporotic medication, whereas MBL after prosthetic treatment was correlated with drug administration route. Further studies with larger sample sizes are required.

Purpose: In Korea, the absence of a modified physical activity (PA) questionnaire specifically tailored for Koreans hinders the accurate assessment of PA among individuals with spinal cord injury (SCI). This study aimed to evaluate PA levels in individuals with SCI using a modified PA questionnaire and to provide insights into their PA patterns in Korea. Methods: A self-reported questionnaire was developed by revising and adapting the Korean version of the International Physical Activity Questionnaire (K-IPAQ) during an advisory meeting. Between April and June 2023, 176 individuals with SCI from metropolitan areas in Korea were recruited to assess their weekly PA. PA was quantified in Metabolic Equivalent Task-min/week (MET-min/week) by multiplying the reported PA duration. Results: The average PA level among individuals with SCI in Korea was 2,907.2±194.8 MET-min/week. By intensity, high-intensity activities accounted for 2,760.0±280.5 MET-min/week, moderate-intensity activities for 1,148.8±89.0 MET-min/week, and low-intensity activities for 1,869.4±110.3 MET-min/week. Approximately half of the participants met the World Health Organization (WHO) recommendations for PA. Conclusion Although Korean individuals with SCI demonstrated higher average PA levels compared to findings from other countries and the WHO recommendations, only about half of the participants met the WHO’s guidelines. These results underscore the need to strengthen efforts to promote PA participation among individuals with SCI.

Purpose: To examine the factors impacting cone contrast sensitivity in Koreans aged > 60 years who are scheduled for cataract surgery and do not have congenital color vision deficiencies. Methods: The ColorDx Cone contrast test HD® (CCT-HD; Konan Medical, Inc., CA, USA) was administered to 33 Korean individuals (33 eyes) to evaluate CCT scores before and after cataract surgery, as well as changes in CCT scores according to the degree of progression by cataract type. Correlations between CCT scores and age, best corrected visual acuity (BCVA), regional retinal thickness, and length of the photoreceptor outer segment (PROS) at the fovea were analyzed in pseudophakic eyes. Results: Average scores for short-, medium-, and long-wavelength cone contrast sensitivity tests (S-CCT, M-CCT, and L-CCT, respectively) improved after surgery (p = 0.010, p = 0.001, and p = 0.028, respectively). Comparing CCT score changes before and after surgery by cataract progression, higher cataract grades were associated with greater CCT score changes, though the differences were not statistically significant (p > 0.05). In pseudophakic eyes, S-CCT scores negatively correlated with age (p = 0.017). No significant correlations were found between S-CCT, M-CCT, and L-CCT scores and BCVA, whereas S-CCT, M-CCT, and L-CCT scores positively correlated with PROS at the fovea (p < 0.001). Conclusions Cone contrast sensitivity in individuals aged > 60 years is influenced by age and cataract status and may serve as a valuable indicator of visual function in clinical research.

Background: Infantile hemangioma (IH) is a common benign vascular tumor that occurs during infancy. Oral propranolol is used as a first-line treatment. However, standardized guidelines for evaluating treatment efficacy, particularly the appropriate timing and parameters for Doppler ultrasound (US), have not been established. This study reports on the evaluation of therapeutic efficacy of oral propranolol solution in IH patients using Doppler US, and aims to propose the appropriate timing and parameters for using Doppler US based on this experience. Methods: A retrospective analysis was conducted on 120 patients with IH who were treated with oral propranolol solution and maintained for over 6 months from May 2017 to April 2023. Doppler US evaluation of IH was performed at diagnosis, 1-2 and 6-12 months after treatment initiation, and 6 months post-therapy cessation. A complete response (CR) was identified as a reduction in vascularity along with a decrease in longest diameter (LD) or thickness of 50% or more. Recurrence was evaluated based on increased vascularity or size 6 months after treatment discontinuation. Results: Of 120 patients with IH, 82 females and 38 males were analyzed. IH was first detected at a median age of 12 days (range, 1-240 days), and treatment began at 76 days (range, 27-570 days), continuing for an average of 10.4 months (range, 5-24 months). Initial Doppler US measurements showed an LD of 2.65±1.52 cm and a thickness of 0.79±0.55 cm, with prominent vascularity. After 1-2 months of treatment, LD and thickness decreased by 12.9% and 25.9%, respectively. By 6-12 months, reductions reached 37.2% and 53.6%. CR occurred in 77 patients (64.2%) after 6-12 months of treatment. Eleven patients (9.2%) experienced a recurrence. Conclusion Doppler US is a valuable modality for evaluating the characteristics, treatment response, and recurrence of IH treated with oral propranolol.

Background: and Purpose: Plasma biomarkers, including phosphorylated tau (ptau217), glial fibrillary acidic protein (GFAP), and neurofilament light chain (NfL), are promising tools for detecting Alzheimer’s disease (AD) pathology. However, cross-laboratory reproducibility remains a challenge, even when using identical analytical platforms such as single-molecule array (Simoa). This study aimed to compare plasma biomarker measurements (ptau217, GFAP, and NfL) between 2 laboratories, the University of Gothenburg (UGOT) and DNAlink, and evaluate their associations with amyloid positron emission tomography (PET) imaging. Methods: Plasma biomarkers were measured using Simoa platforms at both laboratories:the UGOT and DNAlink Incorporation. Diagnostic performance for predicting amyloid PET positivity, cross-laboratory agreement, and the impact of normalization techniques were assessed. Bland-Altman plots and correlation analyses were employed to evaluate agreement and variability. Results: Plasma ptau217 concentrations exhibited strong correlations with amyloid PET global centiloid values, with comparable diagnostic performance between laboratories (area under the curve=0.94 for UGOT and 0.95 for DNAlink). Cross-laboratory agreement for ptau217 was excellent (r=0.96), improving further after natural log transformation. GFAP and NfL also demonstrated moderate to strong correlations (r=0.86 for GFAP and r=0.99 for NfL), with normalization reducing variability. Conclusions Plasma biomarker measurements were consistent across laboratories using identical Simoa platforms, with strong diagnostic performance and improved agreement after normalization. These findings support the scalability of plasma biomarkers for multicenter studies and underscore their potential for standardized applications in AD research and clinical practice.

Background: and Purpose: This clinical practice guideline provides evidence-based recommendations for treatment of dementia, focusing on cholinesterase inhibitors and N-methyl-D-aspartate (NMDA) receptor antagonists for Alzheimer’s disease (AD) and other types of dementia. Methods: Using the Population, Intervention, Comparison, Outcomes (PICO) framework, we developed key clinical questions and conducted systematic literature reviews. A multidisciplinary panel of experts, organized by the Korean Dementia Association, evaluated randomized controlled trials and observational studies. Recommendations were graded for evidence quality and strength using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Results: Three main recommendations are presented: (1) For AD, cholinesterase inhibitors (donepezil, rivastigmine, galantamine) are strongly recommended for improving cognition and daily function based on moderate evidence; (2) Cholinesterase inhibitors are conditionally recommended for vascular dementia and Parkinson’s disease dementia, with a strong recommendation for Lewy body dementia; (3) For moderate to severe AD, NMDA receptor antagonist (memantine) is strongly recommended, demonstrating significant cognitive and functional improvements. Both drug classes showed favorable safety profiles with manageable side effects. Conclusions This guideline offers standardized, evidence-based pharmacologic recommendations for dementia management, with specific guidance on cholinesterase inhibitors and NMDA receptor antagonists. It aims to support clinical decision-making and improve patient outcomes in dementia care. Further updates will address emerging treatments, including amyloid-targeting therapies, to reflect advances in dementia management.