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.

Objective: To classify life stages for companion dogs and cats by identifying clusters in age-specific disease proportions derived from medical records, providing a data-driven foundation for health examination programs. Methods: We collected 505,667 medical records from 82 veterinary facilities in South Korea between 2020 and 2023. Diagnoses were standardized using GPT-4o and S-BioBERT. Following preprocessing, data from 27 facilities yielded 222,706 canine and 39,910 feline records for the final analysis. Principal component analysis and K-means clustering (K = 4) were applied to age-specific disease proportions to identify life stages.The 10 most highest-proportion diagnoses diseases were determined for each cluster. Results: Canine life stages were classified as ≤ 1 year, 2–5 years, 6–10 years, and 11–15+ years.Feline life stages were 1–2 years, 3–8 years, 9–12 years, and 13–15+ years. In dogs, developmental diseases were common in the youngest age group, while chronic diseases were more prevalent in older groups. In cats, oral and urinary diseases were high-ranking, conjunctivitis was most common in the early stage, and chronic diseases increased with age. Conclusions and Relevance: Age-specific diagnosis patterns support four practical life stages for dogs and cats in South Korea. These boundaries can inform evidence-based preventive examination schedules, animal health policy, and pet insurance product design.

Pediatric vulvar hematoma typically results from straddle-type injuries and is usually managed with nonoperative measures. However, rapid progression and the risk of complications in some cases, including tissue necrosis, infection, and urinary retention, necessitate surgical intervention. The highly vascularized anatomy of the vulva allows for rapid hematoma expansion, requiring careful assessment of hematoma size, progression, functional impairment, and hemodynamic stability when determining the treatment strategy. In addition, genital trauma during developmental periods can influence self-perception and psychosexual development, making timely intervention important to prevent aesthetic and functional sequelae. We present two pediatric patients with vulvar hematoma who underwent successful surgical treatment following careful evaluation of both physical and psychological factors. This report emphasizes the importance of a comprehensive, multifaceted approach to the management of pediatric vulvar hematomas.

Background: With the aging population and advancements in medical care worldwide, the number of older patients with end-stage kidney disease continues to rise. This study aimed to identify factors associated with osteoporosis and osteopenia in older patients undergoing incident hemodialysis and assess their impact on mortality. Methods: We analyzed a large multicenter retrospective cohort of patients aged ≥70 years undergoing incident hemodialysis to identify factors associated with osteoporosis using logistic regression analysis and to assess the association of death with osteoporosis and osteopenia using Cox multivariable analysis. Results: Among 710 patients, 39.0% and 19.6% had osteoporosis and osteopenia, respectively. Osteoporosis was significantly associated with female sex, a history of fractures, and the absence of phosphate binder use. During a median follow-up of 36.8 months, 348 participants (58.8%) died. Mortality rates were the highest in the osteoporosis group (79.8%), followed by the osteopenia (77.2%) and normal bone mineral density (BMD) groups (35.2%). Cox regression analysis revealed that even after adjusting for covariates, the osteoporosis group was significantly associated with a higher mortality risk than the normal BMD group. Osteoporosis at the start of hemodialysis was significantly associated with higher mortality. Conclusion We should consider the importance of bone health in patients undergoing incident hemodialysis and pay attention to the use of phosphate binders and fracture prevention.

Background: Obesity is a well-known risk factor for chronic kidney disease and its progression. However, the impact of obesity on the renal function of the elderly population is uncertain. We investigated the association between obesity and renal outcomes in the elderly. Methods: We analyzed 130,504 participants from the Korean National Health Insurance Service-Senior cohort. Obesity was classified according to body mass index (BMI), sex-specific waist circumference (WC), and the presence of metabolic syndrome. The primary outcome was renal function decline, defined as a decline in the estimated glomerular filtration rate (eGFR) of at least 50% from baseline or new-onset end-stage renal disease. Results: During a follow-up period of 559,531.1 person-years (median, 4.3 years), 2,486 participants (19.0%; incidence rate of 4.44 per 1,000 person-years) showed renal function decline. A multivariate Cox proportional hazards model revealed that BMI/WC was not associated with renal function decline. However, the group with metabolic syndrome had a significantly increased risk of renal function decline compared to the group without metabolic syndrome (adjusted hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.13–1.36). Compared with the non-metabolic syndrome group, the adjusted HRs (95% CI) for participants with one through five components were 0.96 (0.84–1.11), 1.10 (0.96–1.27), 1.24 (1.06–1.45), 1.37 (1.12–1.66), and 1.99 (1.42–2.79), respectively (p for trend < 0.001). Conclusion In elderly Korean adults, metabolic syndrome and the number of its components were associated with a higher risk of renal function decline, but BMI or WC was not significant.

Background: Remimazolam is a novel benzodiazepine anesthetic increasingly used for total intravenous anesthesia (TIVA); however, its electroencephalographic signatures—especially in elderly patients—remain poorly characterized. This study aimed to evaluate the relationship between age and intraoperative electroencephalogram (EEG) dynamics during remimazolam-based TIVA. Methods: This prospective observational study analyzed EEG recordings from 69 adult patients receiving remimazolam-based TIVA. We conducted linear regression and Pearson correlation analyses to assess the correlation between age and intraoperative EEG components, including absolute and relative power of EEG frequency bands, frontal coherence, aperiodic components, burst suppression ratio, patient state index (PSI), and spectral edge frequency. Results: Absolute alpha (r = −0.412, P < 0.001), beta (r = −0.459, P < 0.001), and gamma power (r = −0.372, P = 0.002) decreased with age. Conversely, relative delta (r = 0.297, P = 0.013) and theta power (r = 0.433, P < 0.001) increased with age, whereas relative alpha (r = −0.354, P = 0.003) and beta power (r = −0.266, P = 0.027) decreased with age. Frontal coherence of delta (r = −0.436, P < 0.001), theta (r = −0.279, P = 0.02), alpha (r = −0.269, P = 0.025), and beta (r = −0.27, P = 0.025) oscillations decreased with age. Conclusions Older patients exhibited decreased alpha and beta powers, increased delta and theta dominance, and decreased frontal coherence under remimazolam anesthesia guided by the PSI. These findings suggest age-specific alterations in cortical dynamics that may affect EEG monitoring during remimazolam anesthesia.

Objective: This study aimed to compare aneuploidy rates and clinical outcomes between trophectoderm biopsy at fresh blastocyst (biopsy-fresh) followed by vitrification and biopsy at vitrified-warmed blastocyst (biopsy-vitri) followed by next day transfer (without re-vitrification). Methods: This retrospective study included 844 patients undergoing 844 cycles conducted from August 2019 to December 2023. Preimplantation genetic testing for aneuploidy (PGT-A) was performed via trophectoderm biopsy using array comparative genomic hybridization or next-generation sequencing for comprehensive 24-chromosome screening. Patients were divided into two groups based on the blastocyst status at the time of biopsy: the biopsy-fresh group (531 patients) and the biopsy-vitri group (313 patients). Results: The clinical pregnancy rate was significantly higher in the biopsy-fresh group compared to the biopsy-vitri group (58.7% vs. 45.6%; odds ratio [OR], 1.695; 95% confidence interval [CI], 1.215 to 2.364; p=0.002). Furthermore, the biopsy-fresh group showed higher implantation rates (45.6% vs. 32.1%; OR, 1.767; 95% CI, 1.274 to 2.451; p=0.002), ongoing pregnancy or live birth rates per cycle (48.0% vs. 35.8%; OR, 1.652; 95% CI, 1.177 to 2.319; p=0.004), and rates of good-quality blastocysts (57.1% vs. 32.1%, p<0.001) compared with the biopsy-vitri group. Miscarriage rates did not differ significantly between the groups (18.2% vs. 21.4%; OR, 0.818; 95% CI, 0.457 to 1.465; p=0.501). Conclusion Biopsy at fresh blastocyst demonstrated superior clinical outcomes compared with biopsy at vitrified-warmed blastocyst, likely due to better embryo quality. Both biopsy at fresh blastocyst and vitrified-warmed blastocyst remain viable options for PGT-A, with biopsy at vitrified-warmed blastocyst serving as a practical alternative. Embryo quality and euploid status continue to be critical considerations for embryo transfer selection.

Objectives: Large language models (LLMs) demonstrate remarkable potential in healthcare communication. However, whether they can process complex, high-volume medical information, such as stroke-related content, remains insufficiently validated. This study aimed to evaluate the natural language processing capabilities of LLMs in handling such content and to develop an evaluation instrument. Methods: A survey compared educational materials generated by two LLMs (ChatGPT 4.0 and Claude 3) with neurologist-authored content on stroke. The materials were based on two clinical scenarios representing distinct stroke etiologies: cardioembolism and large-artery atherosclerosis. They were evaluated in terms of accuracy, legality, ethics, comprehensiveness, and information delivery. Scores for comprehensiveness and information delivery were compared according to participants’ agreement with the use of LLMs in healthcare. Results: ChatGPT received the highest scores across all domains, except for legality in Scenario 2. In Scenario 1, the ranking for accuracy and summarization of clinical information was, from highest to lowest, ChatGPT, Claude, and the neurologist (η2 = 0.140, p < 0.001; η2 = 0.175, p < 0.001). The same hierarchy was observed in Scenario 2 for accuracy (η2 = 0.077, p < 0.001) and summarization (η2 = 0.194, p < 0.001). Participants who agreed with the use of LLMs in healthcare assigned higher scores for the comprehensiveness (Scenario 1, p = 0.005; Scenario 2, p = 0.007) and information delivery (Scenario 1, p = 0.003; Scenario 2, p = 0.026) of ChatGPT-generated materials than participants who did not agree. Conclusions LLMs demonstrated adequate capability to convey complex content, such as stroke-related information, in an accessible and understandable manner for non-experts.