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.

Purpose: Radical cystectomy (RC) is associated with substantial postoperative morbidity, and unplanned readmission remains common despite advances in perioperative management. However, the association between postoperative readmission due to complications and oncologic outcomes after RC for bladder cancer has not been clearly defined. We evaluated the impact of postoperative readmission on overall survival (OS) and cancer-specific survival (CSS) after RC for bladder cancer. Materials and Methods: We retrospectively analyzed 3,972 patients who underwent RC for bladder cancer in a multicenter cohort. Postoperative readmission was defined as unplanned hospitalization within 90 days postsurgery due to surgery-related complications. Survival outcomes were assessed using the Kaplan-Meier method and compared using the log-rank test. Univariable and multivariable Cox proportional hazards regression analyses were performed to identify independent predictors of OS and CSS. Results: Among the study population, 916 patients (23.1%) experienced postoperative readmission. Baseline and perioperative characteristics were generally comparable between patients with and without readmission. Kaplan-Meier analyses demonstrated significantly worse OS and CSS among patients who experienced postoperative readmission (both log-rank p<0.001). In multivariable analyses adjusting for clinicopathological factors, postoperative readmission remained independently associated with worse OS (hazard ratio [HR], 1.654; 95% confidence interval [CI], 1.464–1.868; p<0.001) and CSS (HR, 1.761; 95% CI, 1.509–2.055; p<0.001). Conclusion Postoperative readmission within 90 days after RC was independently associated with inferior long-term oncologic outcomes. These findings suggest the importance of strategies aimed at preventing postoperative complications and subsequent readmission.

The optimal frequency for hemodialysis in older adults with end-stage kidney disease (ESKD) has not been established. This study aims to investigate whether a twice-weekly dialysis schedule using an incremental approach can reduce hospitalization rates in the elderly with incident dialysis, compared with conventional thrice-weekly dialysis. Methods: We have designed a pragmatic randomized controlled trial to compare the effects of twice-weekly versus thrice-weekly hemodialysis in 428 ESKD individuals (dropout rate 20%) aged 60 years or older with residual kidney function (urine output, >500 mL/ day). The trial will be conducted across 18 referral hospital-based dialysis centers in Korea. Individual participants will be randomized to either a twice-weekly (with incremental approach) or thrice-weekly dialysis group and will be followed up for 24 months. The primary outcome of the study is all-cause hospitalization rate, while secondary outcomes include dialysis-specific hospitalization rates, mortality, quality of life, frailty, and cost-effectiveness. Participants have the flexibility to transfer to other dialysis centers as needed. The decision to increase dialysis frequency will be made by the treating physicians. The study is ongoing and will be completed in May 2026. Conclusion: This study will provide valuable insights into the benefits and risks of twice-weekly dialysis with an incremental approach in elderly with residual kidney function compared to thrice-weekly dialysis.

Background: The effects of perioperative ketamine and esketamine on postoperative nausea and vomiting (PONV) remain unclear. This study aimed to clarify their impact on PONV and related adverse events. Methods: We performed a meta-analysis of randomized controlled trials and observational studies comparing ketamine or esketamine with control agents. The primary outcome was a pooled analysis of PONV and nausea-only data. PONV, postoperative nausea (PON), and postoperative vomiting (POV) were also analyzed separately. Subgroup analyses were conducted by comparator type (placebo, opioid, or non-opioid) and dose categories. Meta-regression was used to assess dose-response relationships. Results: Fifty-five studies (n = 6676) were included. Ketamine and esketamine did not significantly reduce the incidence of pooled PONV risk (risk ratio [RR]: 0.95, 95% CI [0.87–1.04], P = 0.274). No benefit was found versus placebo. Compared with opioids, PONV was reduced (RR = 0.50, 95% CI [0.32–0.77], P = 0.002), but not in the pooled analysis (RR = 0.69, 95% CI [0.43–1.08], P = 0.107). Conversely, compared with non-opioid controls, ketamine/esketamine increased the pooled PONV risk (RR = 1.46, 95% CI [1.03–2.05], P = 0.032). No significant dose-response relationship was found. Both agents increased hallucinations (RR = 1.73, 95% CI [1.35–2.20], P = 0.0002) and drowsiness (RR = 2.18, 95% CI [1.13–4.21], P = 0.024). Conclusions Ketamine and esketamine did not significantly reduce PONV overall. While they showed benefits compared with opioid-based regimens, they may be less effective than non-opioid adjuvants. However, their neuropsychiatric and sedative risks warrant cautious use.

Background: Tibiotalocalcaneal (TTC) arthrodesis is a viable salvage option for failed total ankle arthroplasty (TAA), but it is typically a complex procedure associated with a high complication rate. This study analyzed outcomes of salvage TTC arthrodesis using a retrograde intramedullary (IM) nail without subtalar joint preparation after failed TAA. Methods: This study included 18 patients (18 ankles) who underwent TTC arthrodesis without subtalar joint preparation for failed TAA from July 2008 to March 2023 and were followed up for at least 2 years. Visual analog scale pain scores and Ankle Osteoarthritis Scale pain and disability scores were used to assess functional outcomes. Radiographic union, time to union, complications, and clinical success—defined as pain improvement without the need for revision surgery or amputation—were also evaluated. Results: The mean follow-up duration after TTC arthrodesis was 79.8 months (range, 26–199 months). Tibiotalar joint union was achieved in 13 ankles (72.2%) at a mean of 7.5 months after TTC arthrodesis. Subtalar joint union was achieved in 7 ankles (38.9%). All functional scores improved significantly from preoperatively to the last follow-up. The overall clinical success rate was 83.3% (15 ankles). Conclusions TTC arthrodesis using a retrograde IM nail without subtalar joint preparation produced favorable outcomes in patients with failed TAA. No complications associated with the subtalar joint were observed in any patient during follow-up. Therefore, TTC arthrodesis using a retrograde IM nail without subtalar joint preparation may be a considerable salvage option for failed TAA.

Background: Lifestyle modifications are critical in addressing metabolic dysfunction-associated steatotic liver disease (MASLD); however, the specific macronutrients that most significantly influence the disease’s progression are uncertain. In this study, we aimed to explore the role of carbohydrate, fat, and protein intake in MASLD development using decision trees, random forest models, and cluster analysis. Methods: Participants (n=3,951) from the Korean Genome and Epidemiology Study were included. We used the classification and regression tree analysis to classify participants into subgroups based on variables associated with the incidence of new-onset MASLD. Random forest analyses were used to assess the relative importance of each variable. Participants were grouped into homogeneous clusters based on carbohydrate, protein, fat, and total caloric intake using hierarchical cluster analysis. Subsequently, we used the Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for MASLD risk across the clusters. Results: Carbohydrate intake was identified as the most significant predictor of new-onset MASLD, followed by fat, protein, and total caloric intake. Participants in cluster 3, who consumed a lower proportion of carbohydrate but had higher total caloric, protein, and fat intake, had a lower risk of new-onset MASLD than those in cluster 1 after adjusting for confounders (cluster 1 as a reference; cluster 3: HR, 0.90; 95% CI, 0.82 to 0.99). Conclusion The study’s results highlight the critical role of macronutrient composition, particularly carbohydrate intake, in MASLD development. The findings suggest that dietary strategies focusing on optimizing macronutrients, rather than simply reducing caloric intake, may be more effective in preventing MASLD.

Background/Aims: The absence of standardized clinical minimum inhibitory concentration (MIC) breakpoints for Helicobacter pylori infection has resulted in inconsistent resistance definitions, even within the same research group in Korea. Therefore, establishing epidemiological cutoff values (ECOFFs) is essential for standardization. Methods: The MIC distributions for antibiotics commonly used against H. pylori infection in South Korea were analyzed from 2015 to 2023. A total of 5,925 primary H. pylori isolates were collected from five data sources, and MIC values were determined using the serial 2-fold agar dilution method. The ECOFFinder program was used to establish ECOFFs for six antibiotics. Results: The tentative ECOFFs for amoxicillin and clarithromycin were 0.125 μg/mL. The ECOFFs for levofloxacin, metronidazole, and tetracycline were 0.5, 8.0, and 0.25 μg/mL, respec-tively. The ECOFF for rifabutin could not be determined due to insufficient data. On the basis of these ECOFFs, the resistance rate was 17.9% for amoxicillin, 31.9% for clarithromycin, 40.9% for levofloxacin, 24.7% for metronidazole, and 11.5% for tetracycline. Conclusions This comprehensive analysis defined regional antibiotic resistance patterns and established Korea-specific ECOFFs, providing a foundation for determining clinical breakpoints and optimizing H. pylori eradication strategies.

Purpose: To investigate the association between metabolic syndrome (MetS) and nocturia in a nationally representative U.S. adult population, focusing on individual metabolic components and subgroup differences by age and sex. Materials and Methods: We analyzed data from 8,518 adults aged ≥20 years who participated in the National Health and Nutrition Examination Survey from 2005 to 2014. Nocturia was defined as ≥2 nighttime voids. MetS was defined by the presence of ≥3 National Cholesterol Education Program Adult Treatment Panel III criteria. Multivariate logistic regression and restricted cubic spline (RCS) analyses were used to assess associations, adjusting for demographic and behavioral covariates. Results: Overall, 23.3% of participants had MetS and 29.6% reported nocturia. MetS was independently associated with nocturia (adjusted odds ratio [OR] 1.387, 95% confidence interval 1.236–1.557). A dose–response relationship was observed, with nocturia risk increasing. Central obesity (OR 1.564), elevated fasting glucose (OR 1.397), and elevated blood pressure (OR 1.311) showed the strongest associations. RCS analyses revealed linear associations for waist circumference and systolic blood pressure, and nonlinear associations for diastolic blood pressure and glucose. Sex-specific analyses revealed distinct nonlinear patterns, particularly for waist circumference among male participants and triglyceride levels among female participants. The association remained consistent across most age and sex groups, except in males aged 20–40 years. Conclusions MetS and its components are independently associated with nocturia. The observed sex-specific differences suggest that metabolic contributors to nocturia may differ by sex supporting nocturia as a potential clinical marker of underlying cardiometabolic dysfunction.