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.

Background: and Purpose Whole-exome sequencing (WES) is a valuable tool for identifying causative mutations in adult moyamoya disease (MMD), thereby advancing our understanding of the genetic mechanisms underlying this condition. Here, we conducted the first WESbased association study aimed at identifying genetic modifiers implicated in MMD. Methods: This WES study involved 160 patients with MMD and 189 controls from a multicenter hospital-based biobank, and evaluated combined annotation-dependent depletion (CADD) scores. Mutant-allele frequencies were compared in 369,121 individuals derived from the UK Biobank (UKB) WES. Mutant-allele risk scores (MARSs) were created based on WESidentified mutations. Gene-based association analyses and pooled analyses in East-Asian populations were further performed. Results: Fourteen mutations reached the genome-wide significance criterion (p<5×10-8 ), among which the p.R4810K mutation in the ring finger protein 213 gene (RNF213) showed the strongest significance (odds ratio=117.4, p=8.54×10-24 ). Notably, two mutations—p.G576S (alpha-glucosidase [GAA]) and p.D54N (charged multivesicular body protein 6 [CHMP6])— exhibited high CADD scores of 32 and 25, respectively, whereas the RNF213 p.R4810K mutation demonstrated a moderate deleteriousness score of 10.63. Fourteen mutations exhibited significant differences in allele frequencies between patients and UKB controlled data (p<1×10-8 ).The MARS9 model (incorporating nine missense mutations) showed better predictability for MMD (90.89%). The analysis of gene-based associations revealed four candidate genes: GAA, RNF213, CHMP6, and CARD14 (p=5×10-19 to 4×10-7 ). The subsequent pooled analyses validated four mutations in East Asian populations: p.V1195M, p.D1331G, p.S2334N, and p.R4810K (p<3×10-8 ). Conclusions This pioneering study has corroborated the significance of p.R4810K and identified several causative mutations predisposing patients to MMD, which helps to improve the understanding of its polygenetic nature.

Background and Objectives: Anti-adhesion agents based on hyaluronate-carboxymethyl cellulose (HA-CMC) are widely used in thyroid surgery to reduce postoperative adhesions. However, concerns persist that higher application volumes may increase postoperative drainage and prolong hospitalization. This study aimed to evaluate the impact of different doses of an HA-CMC solution (Guardix-SGⓇ ) on postoperative drainage and clinical outcomes after hemithyroidectomy. Materials and Methods: This prospective study included 107 patients who underwent hemithyroidectomy with central neck lymph node dissection for thyroid cancer between January and October 2024. Patients were randomly assigned to receive either 3 g (n=57) or 6 g (n=50) of Guardix-SGⓇ intraoperatively.Postoperative drainage volume, drain duration, and length of hospital stay were compared between groups.Analysis of covariance and quantile regression were performed to assess the effects of HA-CMC dose and clinical covariates on drainage outcomes. Results: Baseline demographic and pathological characteristics were comparable between the two groups. Total postoperative drainage volume did not differ significantly between the 3 g and 6 g groups, even after adjustment for hospital stay (p=0.283), nor did drain duration. Quantile regression analysis revealed that hypertension was independently associated with increased drainage volume in higher quantiles (0.25– 0.75), whereas the dose of HA-CMC solution had no significant effect across any quantile. Conclusion Application of a higher dose (6 g) of HA-CMC solution did not increase postoperative drainage or prolong drain duration after hemithyroidectomy. These findings support the safe and effective use of higher-dose Guardix-SGⓇ in thyroid surgery.

Objective: This study compared clinical and cosmetic outcomes of cranioplasty using customized three-dimensional (3-D) printed implants versus autologous bone in patients with aneurysmal subarachnoid hemorrhage (aSAH) after decompressive craniectomy (DC). Methods: We retrospectively reviewed 50 patients who underwent cranioplasty after DC for aSAH between July 2018 and December 2023. Patients were divided into the three-dimensional cranioplasty(3-DC, n=26) and autologous bone cranioplasty (AC, n=24) groups. Demographics, aneurysm characteristics, surgical parameters, morphometric analysis of defect coverage, complications, and functional outcomes assessed by the modified Rankin Scale (mRS) were compared. Results: A total of 54 hemispheres underwent cranioplasty. Compared with AC, the 3-DC group had larger defects but achieved higher coverage (96.7% vs. 93.4%, p=0.044) and smaller residual defects (338.7±274.2 mm² vs. 528.5±331.3 mm², p=0.049). Complication rates were lower in 3-DC (9 cases) than AC (15 cases, p=0.0994). Wound dehiscence and fluid collection were more frequent with 3-DC, while bone flap resorption and epidural abscess occurred only with AC. Revision surgery was required in six patients, five initially treated with autologous bone. Neurological outcomes (mRS) were maintained or improved in both groups. Conclusions In aSAH patients undergoing cranioplasty after DC, customized 3-D printed implants achieved significantly better anatomical restoration and showed a numerical trend toward fewer complications compared with autologous bone. While AC remains feasible, its risks of resorption and infection often necessitate revision. 3-D printed implants may be considered a reasonable alternative, particularly in aSAH patients at higher risk of complications.

Background: and Purpose The National Brain Biobank of Korea (NBBK) is a brain bank consortium supported by the Korea Disease Control and Prevention Agency and the Korea National Institute of Health, and was launched in 2015 to support research into neurodegenerative disease dementia (NDD). This study aimed to introduce the NBBK and describes clinicopathological correlations based on analyses of data collected from the NBBK. Methods: Four hospital-based brain banks have been established in South Korea: Samsung Medical Center Brain Bank (SMCBB), Seoul National University Hospital Brain Bank (SNUHBB), Pusan National University Hospital Brain Bank (PNUHBB), and Myongji Hospital Brain Bank (MJHBB). Clinical and pathological data were collected from these brain banks using standardized protocols. The prevalence rates of clinical and pathological diagnoses were analyzed in order to characterize the clinicopathological correlations. Results: Between August 2016 and December 2023, 185 brain specimens were collected and pathologically evaluated (SNUHBB: 117; PNUHBB: 27; SMCBB: 34; MJHBB: 7). The age at consent was 70.8±12.6 years, and the age at autopsy was 71.7±12.4 years. The four-most-common clinical diagnoses were Alzheimer’s disease (AD) dementia (20.0%), idiopathic Parkinson’s disease (15.1%), unspecified dementia (11.9%), and cognitively unimpaired (CU) (11.4%).Most cases of unspecified dementia had a pathological diagnosis of central nervous system (CNS) vasculopathy (31.8%) or AD (31.8%). Remarkably, only 14.2% of CU cases had normal pathological findings. The three-most-common pathological diagnoses were AD (26.5%), CNS vasculopathy (14.1%), and Lewy body disease (13.5%). Conclusions These clinical and neuropathological findings provide a deeper understanding of the mechanisms underlying NDD in South Korea.

Objectives: Smoking causes 8 million deaths annually and significant socioeconomic burdens. Despite several therapies, cessation rates remain low due to nicotine’s addictive properties and withdrawal symptoms. This study evaluates the efficacy of transcutaneous auricular vagus nerve stimulation (taVNS) in reducing nicotine dependence and improving psychological states. Methods: This pilot study enrolled 23 adult smokers aged 19 to 65 years with the Fagerström Test for Nicotine Dependence (FTND) scores over 4 and daily cigarette consumption exceeding 10. Participants were randomized into treatment and control groups. The treatment group received personalized taVNS stimulation targeting the auricular branch of the vagus nerve, applied for 30 minutes, three times daily, for four weeks. The control group received a low-level fixed-current stimulation. Outcomes, including the FTND, cigarettes per day (CPD), the Patient Health Questionnaire-9 (PHQ-9), the Generalized Anxiety Disorder-7 (GAD-7), and the Insomnia Severity Index (ISI), were assessed at baseline, 2 weeks, and 4 weeks. Statistical analyses included the Mann–Whitney U-test and Wilcoxon signed-rank test. Results: The treatment group showed significant reductions in the FTND (2.0 points at 2 weeks, p<0.05; 3.0 points at 4 weeks, p<0.05) and CPD (1.0 fewer cigarette at 2 weeks, p<0.05; 2.0 fewer cigarettes at 4 weeks, p<0.05). Additionally, the PHQ-9 scores decreased significantly in the treatment group (3.0 points at 2 weeks, p<0.05; no further improvement at 4 weeks). However, the GAD-7 and the ISI scores showed no statistically significant changes in either group. The control group exhibited slight improvements in the FTND and the CPD, possibly due to placebo effects or motivation induced by study participation. Conclusions This study highlights taVNS as a promising non-invasive treatment for smoking cessation, effective in reducing nicotine dependence and improving depressive symptoms. However, its effects on anxiety and sleep quality remain unclear. Larger studies are needed to confirm its efficacy and explore optimal parameters and underlying mechanisms.

Purpose: Primary mediastinal large B-cell lymphoma (PMBCL) is a rare subtype of diffuse large B-cell lymphoma.Radiation therapy (RT) has served as the primary treatment option for PMBCL; however, its role has been questioned with the advent of intensified immunochemotherapy. This study aimed to investigate the role of consolidative RT in the primary treatment of PMBCL. Methods: This single-center retrospective study analyzed the survival outcomes of 65 patients newly diagnosed with PMBCL. The patients were divided into three treatment groups: (1) EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab), (2) R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone), and (3) R-CHOP with consolidative RT. Results: The objective response and complete remission rates were 86.2% and 63.1%, respectively, with 3-year pro‑ gression-free survival (PFS) and overall survival (OS) rates of 72% and 81%, respectively. All patients in the R-CHOP + RT group achieved an objective response with better PFS) than those who did not receive consolidative RT (p = 0.028), although there was no significant difference in OS (p = 0.102). Consolidative RT benefited patients with an initially bulky disease or insufficient end-of-treatment response. The predictive value of  18 F-fluorodeoxyglucose positronemission tomography-computed tomography (PET-CT) in assessing the treatment response in PMBCL was revali‑ dated, showing that patients who achieved negative end-of-treatment PET-CT had significantly better survival outcomes than others. Conclusions R-CHOP is a useful alternative regimen when intensified chemotherapy is not feasible. Consolidative RT should be considered in cases with an initially bulky disease and insufficient end-of-treatment response.

Purpose: While fluoropyrimidine-based chemotherapy regimens are recommended second-line treatment for patients with advanced biliary tract cancer (BTC), there have been no studies comparing different regimens head-to-head. Materials and Methods: We performed individual patient-level meta-analysis based on data from the intention-to-treat population of the phase 2b NIFTY trial (liposomal irinotecan [nal-IRI] plus fluorouracil and leucovorin [5-FU/LV] vs. 5-FU/LV; NCT03542508) and the phase 2 FIReFOX trial (modified oxaliplatin plus 5-FU/LV [mFOLFOX] vs. modified irinotecan plus 5-FU/LV [mFOLFIRI]; NCT03464968). Pairwise log-rank tests and multivariable analysis using Cox proportional hazards modeling with shared frailty to account for the trial's effect were used to compare overall survival (OS) between regimens. Results: A total of 277 patients were included. The nal-IRI plus 5-FU/LV group (n=88) showed significantly better OS compared to the mFOLFOX group (n=49, pairwise log-rank, p=0.02), and mFOLFIRI group (n=50, p=0.03). Multivariable analysis showed consistent trends in OS with adjusted hazard ratios of 1.39 (mFOLFOX vs. nal-IRI plus 5-FU/LV: 95% confidence interval [CI], 0.93 to 2.07; p=0.11) and 1.36 (mFOLFIRI vs. nal-IRI plus 5-FU/LV: 95% CI, 0.92 to 2.03; p=0.13), respectively. Compared to the 5-FU/LV group, the mFOLFOX group and the mFOLFIRI group did not show differences in terms of OS (pairwise log-rank p=0.83 and p=0.58, respectively). The nal-IRI plus 5-FU/LV group experienced more frequent diarrhea, while the mFOLFOX group experienced peripheral neuropathy. Conclusion Nal-IRI plus 5-FU/LV showed favorable survival outcomes compared to mFOLFOX, mFOLFIRI, or 5-FU/LV. The safety profiles of these regimens should be considered along with efficacy.

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.

Objectives: Smoking causes 8 million deaths annually and significant socioeconomic burdens. Despite several therapies, cessation rates remain low due to nicotine’s addictive properties and withdrawal symptoms. This study evaluates the efficacy of transcutaneous auricular vagus nerve stimulation (taVNS) in reducing nicotine dependence and improving psychological states. Methods: This pilot study enrolled 23 adult smokers aged 19 to 65 years with the Fagerström Test for Nicotine Dependence (FTND) scores over 4 and daily cigarette consumption exceeding 10. Participants were randomized into treatment and control groups. The treatment group received personalized taVNS stimulation targeting the auricular branch of the vagus nerve, applied for 30 minutes, three times daily, for four weeks. The control group received a low-level fixed-current stimulation. Outcomes, including the FTND, cigarettes per day (CPD), the Patient Health Questionnaire-9 (PHQ-9), the Generalized Anxiety Disorder-7 (GAD-7), and the Insomnia Severity Index (ISI), were assessed at baseline, 2 weeks, and 4 weeks. Statistical analyses included the Mann–Whitney U-test and Wilcoxon signed-rank test. Results: The treatment group showed significant reductions in the FTND (2.0 points at 2 weeks, p<0.05; 3.0 points at 4 weeks, p<0.05) and CPD (1.0 fewer cigarette at 2 weeks, p<0.05; 2.0 fewer cigarettes at 4 weeks, p<0.05). Additionally, the PHQ-9 scores decreased significantly in the treatment group (3.0 points at 2 weeks, p<0.05; no further improvement at 4 weeks). However, the GAD-7 and the ISI scores showed no statistically significant changes in either group. The control group exhibited slight improvements in the FTND and the CPD, possibly due to placebo effects or motivation induced by study participation. Conclusions This study highlights taVNS as a promising non-invasive treatment for smoking cessation, effective in reducing nicotine dependence and improving depressive symptoms. However, its effects on anxiety and sleep quality remain unclear. Larger studies are needed to confirm its efficacy and explore optimal parameters and underlying mechanisms.