Background: and Purpose: Amyloid-beta (Aβ) plaques are key in Alzheimer’s disease (AD), with Aβ positron emission tomography imaging enabling non-invasive quantification.To address regional Aβ deposition, we developed regional Centiloid scales (rdcCL) and commercialized them through the computed tomography (CT)-based BeauBrain Amylo platform, eliminating the need for three-dimensional T1 magnetic resonance imaging (MRI). Objective: We aimed to establish robust regional Aβ cutoffs using the commercialized BeauBrain Amylo platform and to explore the prevalence of subgroups defined by global, regional, and striatal Aβ cutoffs across cognitive stages. Methods: We included 2,428 individuals recruited from the Korea-Registries to Overcome Dementia and Accelerate Dementia Research project. We calculated regional Aβ cutoffs using Gaussian Mixture Modeling. Participants were classified into subgroups based on global, regional, and striatal Aβ positivity across cognitive stages (cognitively unimpaired [CU], mild cognitive impairment, and dementia of the Alzheimer’s type). Results: MRI-based and CT-based global Aβ cutoffs were highly comparable and consistent with previously reported Centiloid values. Regional cutoffs revealed both similarities and differences between MRI- and CT-based methods, reflecting modality-specific segmentation processes. Subgroups such as global(−)regional(+) were more frequent in non-dementia stages, while global(+)striatal(−) was primarily observed in CU individuals. Conclusions Our study established robust regional Aβ cutoffs using a CT-based rdcCL method and demonstrated its clinical utility in classifying amyloid subgroups across cognitive stages. These findings highlight the importance of regional Aβ quantification in understanding amyloid pathology and its implications for biomarker-guided diagnosis and treatment in AD.

Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.

Purpose: Since 1995, the Korean Gastric Cancer Association (KGCA) has been periodically conducting nationwide surveys on patients with surgically treated gastric cancer. This study details the results of the survey conducted in 2023. Materials and Methods: The survey was conducted from March to December 2024 using a standardized case report form. Data were collected on 86 items, including patient demographics, tumor characteristics, surgical procedures, and surgical outcomes. The results of the 2023 survey were compared with those of previous surveys. Results: Data from 12,751 cases were collected from 66 institutions. The mean patient age was 64.6 years, and the proportion of patients aged ≥71 years increased from 9.1% in 1995 to 31.7% in 2023. The proportion of upper-third tumors slightly decreased to 16.8% compared to 20.9% in 2019. Early gastric cancer accounted for 63.1% of cases in 2023.Regarding operative procedures, a totally laparoscopic approach was most frequently applied (63.2%) in 2023, while robotic gastrectomy steadily increased to 9.5% from 2.1% in 2014.The most common anastomotic method was the Billroth II procedure (48.8%) after distal gastrectomy and double-tract reconstruction (51.9%) after proximal gastrectomy in 2023.However, the proportion of esophago-gastrostomy with anti-reflux procedures increased to 30.9%. The rates of post-operative mortality and overall complications were 1.0% and 15.3%, respectively. Conclusions The results of the 2023 nationwide survey demonstrate the current status of gastric cancer treatment in Korea. This information will provide a basis for future gastric cancer research.

Objective: We evaluated the occupational exposure levels of healthcare workers while conducting rotational pressurized intraperitoneal aerosol chemotherapy (RIPAC) using cisplatin in a large animal model. Methods: We performed RIPAC using cisplatin in 6 female pigs and collected surface and air samples during the procedure. Surface samples were obtained from RIPAC devices and personal protective equipment (PPE) by wiping, and air samples were collected around the operating table.All samples were analyzed by inductively coupled plasma–mass spectrometry to detect platinum. Results: Among all surface samples (n=44), platinum was detected in 41 samples (93.2%) but not in all air samples (n=16). Among samples collected from RIPAC devices (n=23), minimum and maximum cisplatin levels of 0.08 and 235.09 ng/cm2 were detected, mainly because of direct aerosol exposure in the abdominal cavity. Among samples collected from healthcare workers’ PPE (n=21), 18 samples (85.7%) showed contamination levels below the detection limit, with a maximum of 0.23 ng/cm2 . There was no significant contamination among samples collected from masks, shoes, or gloves. Conclusion During the RIPAC procedures, there is a potential risk of dermal exposure, as platinum, a surrogate material for cisplatin, was detected at low concentration levels in some surface samples. However, the respiratory exposure risk was not identified, as platinum was not detected in the airborne samples in this study.

Background: With growing elderly populations, management of patients with acute stroke is increasingly important. In South Korea, the Acute Stroke Quality Assessment Program (ASQAP) has contributed to improving the quality of stroke care and practice behavior in healthcare institutions. While the mortality of hemorrhagic stroke remains high, there are only a few assessment indices associated with hemorrhagic stroke. Considering the need to develop assessment indices to improve the actual quality of care in the field of acute stroke treatment, this study aims to investigate the current status of human resources and practices related to the treatment of patients with acute stroke through a nationwide survey. Methods: For the healthcare institutions included in the Ninth ASQAP of the Health Insurance Review and Assessment Service (HIRA), data from January 2022 to December 2022 were collected through a survey on the current status and practice of healthcare providers related to the treatment of patients with acute stroke. The questionnaire consisted of 19 items, including six items on healthcare providers involved in stroke care and 10 items on the care of patients with acute stroke. Results: In the treatment of patients with hemorrhagic stroke among patients with acute stroke, neurosurgeons were the most common providers. The contribution of neurosurgeons in the treatment of ischemic stroke has also been found to be equivalent to that of neurologists. However, a number of institutions were found to be devoid of healthcare providers who perform definitive treatments, such as intra-arterial thrombectomy for patients with ischemic stroke or cerebral aneurysm clipping for subarachnoid hemorrhage. The intensity of the workload of healthcare providers involved in the care of patients with acute stroke, especially those involved in definitive treatment, was also found to be quite high. Conclusion Currently, there are almost no assessment indices specific to hemorrhagic stroke in the ASQAP for acute stroke. Furthermore, it does not reflect the reality of the healthcare providers and practices that provide definitive treatment for acute stroke. The findings of this study suggest the need for the development of appropriate assessment indices that reflect the realities of acute stroke care.

Background: Severe fever with thrombocytopenia syndrome virus (SFTSV) is a lethal threat.Increasing Severe fever with thrombocytopenia syndrome (SFTS) risk in Asia and the United States stems from the spread of natural host, Haemaphysalis longicornis. Rapid and accurate SFTSV molecular diagnosis is crucial for treatment decisions, reducing fatality risk. Methods: Blood samples from 17 suspected SFTS patients at Chuncheon Sacred Heart Hospital (September-December 2022) were collected. SFTSV was diagnosed using two reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assays from Gangwon Institute of Health and Environment (RT-qPCR/GIHE) and Asan Medical Center (RT-qPCR/AMC). To address RT-qPCR disparities, amplicon-based MinION sequencing traced SFTSV genomic sequences in clinical samples. Results: In two samples (N39 and N50), SFTSV was detected in both RT-qPCR/GIHE and RTqPCR/AMC. Among 11 samples, RT-qPCR/AMC exclusively detected SFTSV. In four samples, both assays yielded negative results. Amplicon-based MinION sequencing enabled nearly whole-genome sequencing of SFTSV in samples N39 and N50. Among 11 discordant samples, five contained significant SFTSV reads, aligning with the RT-qPCR/AMC findings. However, another six samples showed insufficient viral reads in accordance with the negativity observed in RT-qPCR/GIHE. The phylogenetic pattern of SFTSV demonstrated N39 formed a genetic lineage with genotype A in all segments. SFTSV N50 grouped with the B-1 sub-genotype for L segment and B-2 sub-genotype for the M and S segments, indicating genetic reassortment. Conclusion The study demonstrates the robust sensitivity of amplicon-based MinION sequencing for the direct detection of SFTSV in clinical samples containing ultralow copies of viral genomes. Next-generation sequencing holds potential in resolving SFTSV diagnosis discrepancies, enhancing understanding of diagnostic capacity, and risk assessment for emerging SFTSV.

Objective: : Korea’s healthcare system and policy promotes early, actively stroke treatment to improve prognosis. This study represents stroke epidemiology and outcomes in Korea. Methods: : This study investigated data from the Acute Stroke Assessment Registry. The registry collects data from over 220 hospitals nationwide, focusing on quality stroke service management. Data analysis included patient demographics, stroke severity assessment, and discharge prognosis measurement using standardized scales. Results: : Eighty-six thousand five hundred sixty-eight acute stroke patients were collected with demographic and clinical characteristics during 18 months from 2016, 2018, and between 2020 to 2021, focusing on acute subarachnoid hemorrhage (SAH), acute intracerebral hemorrhage (ICH), and acute ischemic stroke. Of these 86568 patients, 8.3% was SAH, 16.3% ICH, and 74.9% ischemic stroke. Trends showed decreasing SAH and increasing ICH cases over the years. 68.3% stroke patients had the clear onset time. 49.6% stroke patients arrived within 4.5 hours of symptom onset, with more patients treated at general hospitals. Good functional outcomes at discharge was obtained with 58.3% of acute stroke patients, 55.9% of SAH patients, 34.6% of ICH patients, and 63.8% of ischemic stroke patients. Conclusion : The results showed that ischemic stroke was the most common subtype, followed by ICH and SAH. Prognosis differed among subtypes, with favorable outcomes more common in ischemic stroke and SAH compared to ICH.

Irritable bowel syndrome (IBS) is a chronic, disabling, and functional bowel disorder that significantly affects social functioning and reduces quality of life and increases social costs. The Korean Society of Neurogastroenterology and Motility published clinical practice guidelines on the management of IBS based on a systematic review of the literature in 2017, and planned to revise these guidelines in light of new evidence on the pathophysiology, diagnosis, and management of IBS. The current revised version of the guidelines is consistent with the previous version and targets adults diagnosed with or suspected of having IBS. These guidelines were developed using a combination of de novo and adaptation methods, with analyses of existing guidelines and discussions within the committee, leading to the identification of key clinical questions. Finally, the guidelines consisted of 22 recommendations, including 3 concerning the definition and risk factors of IBS, 4 regarding diagnostic modalities and strategies, 2 regarding general management, and 13 regarding medical treatment. For each statement, the advantages, disadvantages, and precautions were thoroughly detailed. The modified Delphi method was used to achieve expert consensus to adopt the core recommendations of the guidelines. These guidelines serve as a reference for clinicians (including primary care physicians, general healthcare providers, medical students, residents, and other healthcare professionals) and patients, helping them to make informed decisions regarding IBS management.

Background: Colorectal carcinomas (CRCs) with caudal-type homeobox 2 (CDX2) loss are recognized to pursue an aggressive behavior but tend to be accompanied by a high density of tumor-infiltrating lymphocytes (TILs). However, little is known about whether there is an interplay between CDX2 loss and TIL density in the survival of patients with CRC. Methods: Stage III CRC tissues were assessed for CDX2 loss using immunohistochemistry and analyzed for their densities of CD8 TILs in both intraepithelial (iTILs) and stromal areas using a machine learning-based analytic method. Results: CDX2 loss was significantly associated with a higher density of CD8 TILs in both intraepithelial and stromal areas. Both CDX2 loss and a high CD8 iTIL density were found to be prognostic parameters and showed hazard ratios of 2.314 (1.050–5.100) and 0.378 (0.175–0.817), respectively, for cancer-specific survival. A subset of CRCs with retained CDX2 expression and a high density of CD8 iTILs showed the best clinical outcome (hazard ratio of 0.138 [0.023–0.826]), whereas a subset with CDX2 loss and a high density of CD8 iTILs exhibited the worst clinical outcome (15.781 [3.939–63.230]). Conclusions Altogether, a high density of CD8 iTILs did not make a difference in the survival of patients with CRC with CDX2 loss. The combination of CDX2 expression and intraepithelial CD8 TIL density was an independent prognostic marker in adjuvant chemotherapy-treated patients with stage III CRC.