Purpose: Sentinel lymph node biopsy (SLNB) using dye and isotope (DUAL) is recommended over the dye-only (DYE) method after neoadjuvant chemotherapy (NCT) due to potentially lower false-negative rates. However, the long-term outcome of either method is unclear. We aimed to compare the long-term oncological outcomes of DYE versus DUAL SLNB methods in patients who received NCT. Materials and Methods: In this retrospective cohort study, 893 patients who underwent SLNB following NCT and had pathologically negative lymph nodes were included. After propensity score matching for cT, cN, and pT categories, 280 patients were in the DYE group and 560 in the DUAL group. Indigo carmine was used for dye and Tc-99m antimony trisulfate for isotope mapping. Results: Median follow-up was 75.6 months in the DYE group and 83.0 months in the DUAL group. Mean (±standard deviation) number of harvested sentinel nodes was 6.7 (±3.9) and 6.7 (±3.3) in the DYE and DUAL groups (p=0.875). Five-year distant metastasisfree survival was 95.2% in DYE group and 93.3% in DUAL group (hazard ratio [HR], 1.45; 95% confidence interval [CI], 0.82 to 2.57; p=0.192). Disease-free survival (HR, 0.97; 95% CI, 0.69 to 1.50; p=0.914) and overall survival (HR, 0.98; 95% CI, 0.56 to 1.69; p=0.954) were not significantly different. Axillary recurrence rate was 1.8% and 2.5% in DYE and DUAL groups (p=0.647). Conclusion Long-term oncological outcomes did not significantly differ between DYE and DUAL SLNB methods. The dye-only method can be safely recommended for breast cancer patients who received NCT.

Purpose: Biliary atresia (BA) is a rare but progressive cholangiopathy and the leading cause of pediatric liver transplantation worldwide. The Korean Association of Pediatric Surgeons (KAPS) has conducted three national surveys (2001, 2011, and 2023) to assess long-term trends in the diagnosis, treatment, and outcomes of BA. This study provides a comparative analysis of the 2nd and 3rd national surveys, with reference to selected findings from the 1st survey. Methods: This study included 453 patients from the 3rd national survey (2011–2021) and 435 patients from the 2nd survey (2001–2010), all of whom underwent Kasai portoenterostomy. Data were collected via electronic case report forms from pediatric surgical centers nationwide. Comparisons were made regarding demographics, clinical features, diagnostic patterns, operative details, follow-up outcomes, and survival. Kaplan–Meier analysis was used to evaluate long-term survival. Results: The mean number of BA patients per year remained stable between surveys (43.5 in the 2nd, 41.18 in the 3rd), though centralization of care increased, with 61.5% of cases managed by two major institutions in the 3rd survey. The median age at surgery decreased, and the use of preoperative imaging (especially magnetic resonance cholangiopancreatography) increased. The 10-year native liver survival rate declined from 59.8% to 53.7%, while overall 10-year survival improved slightly (92.9% to 93.2%). Postoperative complications, such as cholangitis and liver failure, persisted but were better categorized. The 3rd survey also reported improved mortality (4.9%) and reduced follow-up loss (11.5%) compared to the 2nd survey. Conclusion While overall survival after Kasai operation has remained high and even improved, native liver survival has slightly declined. The findings reflect earlier diagnosis, more consistent diagnostic imaging, and increasing centralization of care. These trends underscore the importance of long-term nationwide data collection in guiding future strategies for BA management in Korea.

Purpose: This study aims to investigate and compare the incidence, demographic characteristics, clinical manifestations, preoperative diagnostic methods, anatomical classifications, associated anomalies, operative treatments, and postoperative outcomes of patients with intestinal atresia treated by the members of the Korean Association of Pediatric Surgeons (KAPS) through three nationwide surveys. Methods: KAPS conducted 3 national surveys in 1998, 2010, and 2024 to examine the patients diagnosed with intestinal atresia. In preparation for the survey, we developed a customized case registration form to obtain data on patient sex, birth weight, gestational age, clinical manifestations, preoperative diagnostic methods, anatomical types, associated anomalies, operative treatments, and postoperative outcomes. Authorized KAPS members completed the case registration form. Results: The first, second, and third national surveys included 218, 222, and 236 individuals diagnosed with intestinal atresia, respectively. The male-to-female ratios were 1.5:1, 1.1:1, and 1.1:1, respectively. The first, second, and third national surveys revealed that 34.3%, 43.3%, and 53.4% of patients were born before 37 weeks of gestation, respectively. Additionally, 28.7%, 32.0%, and 40.7% of patients had a birth weight under 2,500 g. In the third national survey, duodenoduodenostomy was the most common procedure, performed in 70 out of 82 patients diagnosed with duodenal atresia. Resection and anastomosis were the main surgical procedures conducted in 47 out of 54 cases of jejunal atresia and 74 out of 92 cases of ileal atresia. The mortality rates in the first, second, and third national surveys were 13.8%, 3.6%, and 1.3% respectively, with the lowest rate observed in the third national survey. Conclusion These national surveys offer valuable insights into the current state of intestinal atresia, including specific surgical interventions and postoperative outcomes in South Korea. For pediatric surgeons aiming to enhance their understanding of intestinal atresia and its treatment options, these surveys could be an indispensable resource and guide.

Background: Monopolar radiofrequency devices for facial skin tightening offer a promising non-invasive approach that targets the deep dermis to prompt immediate collagen contraction and subsequent remodeling.However, non-clinical evidence supporting the efficacy and mechanisms of action of these treatments remains limited, despite their increasing use. This study aimed to evaluate the effectiveness and safety of a dualfrequency non-invasive monopolar radiofrequency (NMRF) device using a porcine model, directly comparing a conventional 6.78 MHz setting with a dual-frequency (6.78 + 2 MHz) mode. Methods: Female porcine subjects were treated using an innovative NMRF device (XERF; Cynosure Lutronic Inc.). Efficacy was assessed histologically for up to 1 month. Safety was evaluated through thermal skinsurface monitoring and standard assessments. Results: When compared with 6.78 MHz alone, the dual-frequency (6.78 + 2 MHz) mode produced greater immediate thickening and shortening of deep dermal collagen bundles and more prominent remodeling of subcutaneous fibrous septa. At 1 month, the dual-frequency treatment yielded larger increases in dermal collagen density, more regular bundle alignment, and higher elastin signals. Surface temperature remained below 43ºC, and no tissue damage was observed following NMRF treatment. Conclusion Our research strongly indicates that immediate tissue contraction occurs following treatment and that dual-frequency application results in more substantial collagen reconstruction. In the long term, NMRF stimulates the production of new collagen and elastin. The dual-frequency mode enhances these effects, supporting its use in effective and safe skin tightening and rejuvenation.

Circulating tumor DNA (ctDNA) has emerged as a promising tool for various clinical applications, including early diagnosis, therapeutic target identification, treatment response monitoring, prognosis evaluation, and minimal residual disease detection. Consequently, ctDNA assays have been incorporated into clinical practice. In this review, we offer an indepth exploration of the clinical implementation of ctDNA assays. Notably, we examined existing evidence related to pre-analytical procedures, analytical components in current technologies, and result interpretation and reporting processes. The primary objective of this guidelines is to provide recommendations for the clinical utilization of ctDNA assays.

Next-generation sequencing (NGS)-based liquid biopsy using peripheral blood offers a minimally invasive approach to detect tumor-derived circulating tumor DNA (ctDNA). Given the low abundance of ctDNA, accurate analysis is crucial, necessitating external quality assessments.Since 2020, the Korean Association of External Quality Assessment Service has conducted proficiency testing for NGS-based liquid biopsy. This study reviews the proficiency testing results from 2020 to 2023. The program was conducted biannually. Specimens were created by spiking fragmented DNA into fresh frozen plasma to simulate actual clinical samples. The number of target genes reported increased from 5 in 2020 to 17 in 2023. Results were assessed based on concordance with those obtained from targeted NGS panel testing performed before shipping the manufactured specimens.Participating laboratories used various NGS instruments and reagents. The read depth for each genetic variant varied across laboratories, while the reported read percentage of detected variants was generally consistent.Most laboratories accurately reported variants; however, some discrepancies related to variant position descriptions or incorrect reference sequence transcripts were noted. This study evaluates the performance of Korean clinical laboratories in NGS-based liquid biopsy. Continued vigilance in result reporting is necessary, and ongoing external quality assessments can enhance the reliability of NGS-based liquid biopsy testing.

This study aimed to analyze the correlation between smoking and coronavirus disease 2019 (COVID-19) severity by region and gross domestic product (GDP). The regions were categorized by continent and GDP rankings. Studies conducted between June 3, 2020 and March 27, 2023 were searched to compare the severity of COVID-19 between smokers and non-smokers according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Compared with never-smokers, the smokers’ COVID-19 severity scores were 1.48 (confidence interval [CI]: 1.25–1.75) in Asia, 1.24 (CI: 1.05–1.46) in the Middle East, 1.32 (1.21–1.45) in Europe, 1.39 (1.30–1.49) in North America, 1.69 (1.22–2.34) in South America, and 2.87 (1.82–4.53) in Africa. By GDP, the smokers’ COVID-19 severity scores were higher than those of never-smokers: 1.42 (1.32–1.53) in high-GDP countries, 1.33 (1.25–1.41) in middle-GDP countries (11th–50th), and 1.53 (0.85–2.76) in low-GDP countries. The COVID-19 severity in smokers was significantly higher in low-GDP countries than in high- and middle-income countries. The high COVID-19 death rate among smokers in the African continent and low-GDP countries is thought to stem from the lack of medical management systems compared with other countries. In addition to medical treatment, environmental or socioeconomic factors can increase the severity.