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.

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.

Purpose: Radiotherapy (RT) remains a cornerstone of curative treatment for localized and locally advanced prostate cancer. However, dose escalation to improve tumor control is often constrained by the proximity of the rectum, which increases the risk of gastrointestinal (GI) and genitourinary toxicities. Biodegradable rectal spacers inserted between the prostate and rectum have emerged as an effective approach to reduce rectal radiation exposure. This guideline provides evidence-based recommendations on indications, contraindications, procedural standards, and clinical management for biodegradable rectal spacer insertion during prostate cancer RT. Materials and Methods: This guideline was developed by a multidisciplinary expert panel through a systematic review of the literature, analysis of international guidelines (National Comprehensive Cancer Network, European Association of Urology, American Society for Radiation Oncology), and expert consensus among radiation oncologists, radiologists, and urologists with clinical experience in spacer insertion. The strength of each recommendation and the level of evidence were classified according to the modified GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Results: Spacer insertion is conditionally recommended (Grade C, Level I) for patients receiving definitive external-beam RT without rectal invasion. It reduces the high-dose rectal irradiation volume (V70–75) by >50%, decreases acute GI toxicity, and helps maintain bowel-related quality of life. However, the benefit for late severe toxicity (grade 2 or higher) remains debated in recent meta-analyses. Contraindications include rectal invasion, anatomical inaccessibility, infection, and material hypersensitivity. Procedures should be performed under local anesthesia in a sterile environment by trained physicians. Short-course antibiotics and simulator-based training, including completion of multiple supervised cases, are advised. Conclusion Biodegradable rectal spacer insertion is clinically validated and effective in reducing acute rectal toxicity. Although pivotal trials demonstrated a favorable procedural safety profile, real-world postmarket data include reports of rare but severe procedural complications. This guideline provides standardized recommendations tailored to Korean clinical practice while remaining consistent with international standards, emphasizing the importance of operator training and careful patient selection.

Background: Menopausal status can increase the risk of cardiocerebrovascular diseases (CCVDs) in women with type 2 diabetes mellitus (T2DM). Regular exercise is well-known to reduce this risk. This study explored the impact of exercise on CCVD and mortality in women with T2DM according to their menopausal status. Methods: A total of 32,477 premenopausal and 53,690 postmenopausal Korean women with T2DM aged 40 to 60 years from a national health examination cohort (2009 to 2018) were included. We evaluated risks for stroke, myocardial infarction (MI), and mortality based on exercise intensity. Cox proportional hazard regression analyses were performed to obtain the adjusted hazard ratio (aHR) and 95% confidence interval. Results: Exercise reduced stroke, MI, and mortality risks in women with T2DM, regardless of menopausal status. The highest effects of aHR compared to the sedentary group were 0.68 for stroke, 0.66 for MI, and 0.81 for mortality. Postmenopausal women experienced significant MI risk reductions at most exercise intensities, with the greatest reduction in the ≥1,500 metabolic equivalent of task score group unlike premenopausal women. However, stroke and mortality risk reductions in postmenopausal women were less pronounced compared to premenopausal women. Conclusion Exercise reduces CCVD risk in women with T2DM across menopausal status. Postmenopausal women with T2DM had more benefits from exercise on MI but fewer benefits on stroke and mortality than premenopausal women. In premenopausal women with T2DM, exercise was not associated with a lower MI risk.

Background: The prevalence of diabetes mellitus and early-onset dementia (EOD), defined as dementia diagnosed at an age <65 years, is increasing worldwide, with significant socioeconomic implications. We investigated the association between diabetes, prediabetes, and EOD, focusing on the influence of diabetes duration on EOD risk. Methods: Using the Korean National Health Insurance Service database, we analyzed data from 1,979,509 patients aged 40–60 years who underwent health checkups in 2009. Patients were categorized into five groups: normal, impaired fasting glucose (IFG), newly diagnosed diabetes, diabetes duration <5 years, and diabetes duration ≥5 years. Cox proportional hazard models were used to estimate the adjusted hazard ratios (aHRs) for EOD after adjusting for demographic and clinical covariates. Results: During the observation period (mean 7.75 years), 8,921 patients with EOD were identified. The diabetes group demonstrated a significantly higher incidence of EOD compared to the normal group (aHR, 1.334; 95% confidence interval [CI], 1.226 to 1.451). EOD risk increased with longer diabetes duration, with the highest risk observed in patients with diabetes ≥5 years (aHR, 1.543; 95% CI, 1.368 to 1.741). No significant difference was observed between the IFG and normal groups (aHR, 0.989; 95% CI, 0.938 to 1.043). Additionally, the hypertension group exhibited a significantly higher incidence of EOD compared to the non-hypertension group (aHR, 1.364; 95% CI, 1.291 to 1.442). Conclusion Diabetes is independently associated with increased risk of EOD, and this risk increases with longer diabetes duration. This association remained significant regardless of the presence and duration of hypertension.

Purpose: Declines in masticatory function have been reported to be closely associated with cognitive impairment and reduced brain activity in older adults. This study aimed to investigate the effects of intraoral vibratory stimulation on masticatory function, cognitive performance, and brain activity in elderly individuals and to evaluate its potential efficacy. Materials and Methods: Participants were divided into a vibration-stimulation group (n=9) and a non-vibration control group (n=7). Baseline assessments were conducted at the first visit. Participants then received either vibratory stimulation or a wash-out (control) condition for two weeks, followed by the same assessments at the final visit. Evaluation measures were dental assessments (maximum bite force, masticatory performance, and salivary flow rate), cognitive tests (CANTAB, paper-based and computerized tests), quantitative electroencephalography (qEEG), and functional magnetic resonance imaging (fMRI) during a short-term memory task. Results: No significant long-term effects or statistically meaningful differences were observed between the two groups in cognitive performance or brain activity. Similarly, no pre- to post-intervention differences were found between groups in dental measures related to masticatory function (maximum bite force, masticatory performance, and salivary flow rate). Due to the limited sample size, this study functioned as a pilot study focusing on descriptive rather than inferential statistical analysis. Conclusion Intraoral vibratory stimulation did not demonstrate immediate or clear effects on cognitive function or brain activity in older adults, suggesting the need for optimization of stimulation parameters such as location and intensity. Future studies with larger sample sizes and improved stimulation methods replicating masticatory function are warranted to further explore the potential cognitive benefits.

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.

Purpose: Obesity and metabolic syndrome are acknowledged as key factors contributing to the development of non-alcoholic fatty liver disease (NAFLD). Vitamin D (VitD) is a multifaceted secosteroid hormone known for its anti-fibrotic and anti-inflammatory properties, with its deficiency often linked to obesity. Our study aimed to investigate whether VitD supplementation could mitigate the liver pathology associated with NAFLD. Materials and Methods: The NAFLD model was developed by subjecting male C57BL/6 mice to a high-fat diet (HFD) for 14 weeks.These mice were supplemented with VitD through intraperitoneal injection at a dosage of 7 μg/kg, administered three times per week for 7 weeks. Results: HFD resulted in VitD deficiency, insulin resistance, and increased liver weight. It elevated serum levels of liver aminotransferases and triglyceride, ultimately leading to steatohepatitis with fibrosis. This model exhibited increased levels of transforming growth factor (TGF)-β1, pro-inflammatory cytokines, HNF4α transcription factors, reactive oxygen species (ROS), renin-angiotensin system activity, and epithelial-mesenchymal transitions (EMT) within the liver. Supplementation with VitD resulted in the recovery of liver weight, improvement in histologic features associated with steatohepatitis, and reduction in alanine aminotransferases and triglyceride levels induced by the HFD. Additionally, it mitigated the HFD-induced over-expressions of TGF-β1 and fibrosis-related genes, along with pro-inflammatory cytokines and ROS. Notably, no adverse effect was found due to VitD supplementation in this model. Conclusion VitD ameliorates steatohepatitis within obesity-induced NAFLD through its multifaceted pathways. VitD supplementation emerges as a potentially safe, cost-effective, and direct treatment approach for NAFLD patients dealing with obesity or metabolic dysfunction.

Purpose: Obesity and metabolic syndrome are acknowledged as key factors contributing to the development of non-alcoholic fatty liver disease (NAFLD). Vitamin D (VitD) is a multifaceted secosteroid hormone known for its anti-fibrotic and anti-inflammatory properties, with its deficiency often linked to obesity. Our study aimed to investigate whether VitD supplementation could mitigate the liver pathology associated with NAFLD. Materials and Methods: The NAFLD model was developed by subjecting male C57BL/6 mice to a high-fat diet (HFD) for 14 weeks.These mice were supplemented with VitD through intraperitoneal injection at a dosage of 7 μg/kg, administered three times per week for 7 weeks. Results: HFD resulted in VitD deficiency, insulin resistance, and increased liver weight. It elevated serum levels of liver aminotransferases and triglyceride, ultimately leading to steatohepatitis with fibrosis. This model exhibited increased levels of transforming growth factor (TGF)-β1, pro-inflammatory cytokines, HNF4α transcription factors, reactive oxygen species (ROS), renin-angiotensin system activity, and epithelial-mesenchymal transitions (EMT) within the liver. Supplementation with VitD resulted in the recovery of liver weight, improvement in histologic features associated with steatohepatitis, and reduction in alanine aminotransferases and triglyceride levels induced by the HFD. Additionally, it mitigated the HFD-induced over-expressions of TGF-β1 and fibrosis-related genes, along with pro-inflammatory cytokines and ROS. Notably, no adverse effect was found due to VitD supplementation in this model. Conclusion VitD ameliorates steatohepatitis within obesity-induced NAFLD through its multifaceted pathways. VitD supplementation emerges as a potentially safe, cost-effective, and direct treatment approach for NAFLD patients dealing with obesity or metabolic dysfunction.