Objective: We elucidated the effect of monochorionicity on neonatal and long-term neurologic outcomes on an individual basis in triplets. Methods: We retrospectively reviewed the perinatal outcomes and development and growth at 18 to 24 months corrected age (CA) of triplets born alive between 24 and 32 weeks of gestational age (GA) between 2009 and 2021 from the Seoul National University Hospital database. Neurod­evelopmental impairment (NDI) was defined as any delay among the Bayley-III domains (motor and language), cerebral palsy, hearing impairment, or visual loss and was performed at a CA of 18 to 24 months. Results: We included 40 sets of triplets (120 infants), comprising 26, 10, and 4 sets of trichorionic (TC), dichorionic (DC), and monochorionic (MC) triplets, respectively. Ten infants, unaffected by monochorionicity out of 30 DC infants, were included in the non-MC group. Eighty-eight infants were included in the non-MC group, and 32 infants were affected by monochorionicity. In vitro fertilization-embryo transfer was more frequent in the non-MC group (P<0.05), and twin-to-twin transfusion syndrome affected only the MC group (P<0.01). At 24 months of CA, a combined delay of language and cognition in Bayley-III was evident in the MC group (P<0.05). Although NDI did not significantly differ between the 2 groups (P=0.059), the composite outcome of NDI+ postnatal death was significantly different (P<0.05). NDI+ postnatal death correlated with GA, Z-score of birth weight, brain injury, and monochorionicity in the univariate analysis (P<0.05). Multivariate analysis revealed a significant correlation between monochorionicity and NDI+ postnatal death. (P<0.05). Conclusion Monochorionicity is associated with adverse long-term neurodevelopmental out comes.

Purpose: This study compares the dosimetric properties of EBT3 and EBT4 GAFchromic films in transmission and reflection scanning modes, focusing on dose response, sensitivity, and postirradiation stability. Methods: The EBT3 and EBT4 films were irradiated at doses of 0–10 Gy using a Varian TrueBeam linear accelerator at 6 MV. The films were scanned at intervals between 1 and 336 hours after irradiation in both transmission and reflection modes. Net optical density (NetOD) values from each scan were used to evaluate dose response and sensitivity, with calibration curves created for each film and scan mode. Dose differences between calculated and delivered doses were assessed over time. Results: The EBT3 and EBT4 films exhibited similar dose–response curves and stable NetOD values across both scanning modes. However, EBT4 exhibited reduced sensitivity variability in response to dose changes. After irradiation, NetOD values increased up to 24 hours before stabilizing, suggesting that a 24-hour scan time is sufficient for consistent measurements. Dose differences between films and modes remained within ±4%. Conclusions EBT4 offers comparable dosimetric performance to EBT3, with additional benefits, such as improved dose–response linearity and reduced sensitivity fluctuations. The findings indicate that EBT4 can serve as a reliable successor to EBT3.

Background: The 2023 Obesity Fact Sheet aims to present an updated overview of obesity prevalence across all age groups, including children and adolescents. Methods: This study included individuals aged ≥20 years (n=16,941,423 in 2021) who underwent health checkups provided by the Korean National Health Insurance Service between 2012 and 2021. The prevalence of obesity and abdominal obesity was standardized by age and sex using data from the 2010 population and housing census. For children and adolescents (6 to 18 years) (n= 884 in 2021), we used the Korea National Health and Nutrition Examination Survey (2012 to 2021), and obesity was defined by the corresponding sex- and agespecific body mass index percentile of 95th or greater based on the 2017 Korean National Growth Chart for Children and Adolescents. Results: The overall prevalence of obesity in 2021 is 38.4% (49.2% in men and 27.8% in women), which is a 1.27-fold increase from 30.2% in 2012. The prevalence of obesity has increased across all age groups, particularly among those aged 20, 30, and 80 years. The prevalence of class III obesity substantially increased from 0.35% (men) and 0.42% (women) in 2012 to 1.21% and 0.97% in 2021, with 3.46- and 2.31-fold increases, respectively.This increase was particularly pronounced in young adults. The prevalence of obesity in children and adolescents has surged from 9.7% in 2012 to 19.3% in 2021, with a greater increase among boys. Conclusion Our study provides information on the current status of obesity prevalence based on the 2023 Obesity Fact Sheet, emphasizing the urgency of implementing timely strategies to reverse this increasing trend.

Background: While Korea maintains a low prevalence of human immunodeficiency virus (HIV), the number of newly diagnosed cases has been steadily rising, reaching approximately 1,000 annually in recent years. The 2022 annual report from the Korea Disease Control and Prevention Agency revealed that women living with HIV (WLWH) constitute 6.4% of the total confirmed people living with the HIV population, totaling 1,219 individuals. Despite this, only a few studies have focused on WLWH in Korea. This study aims to analyze the epidemiological and clinical characteristics of WLWH in Korea. Materials and Methods: We retrospectively collected data by reviewing the medical records of all WLWH who visited 10 urban referral hospitals across Korea between January 2005 and May 2023. Results: A total of 443 WLWH were enrolled in this study. The predominant risk exposure was heterosexual contact, with 235 (53%) participants either married or cohabiting with a male partner at their initial clinic visit. Among the participants, 334 (77.7%) were Korean, 27 (6.1%) were Southeast Asian, and 19 (4.3%) were African. Antiretroviral therapy was initiated by 404 WLWH (91.2%). We observed 118 pregnancies in WLWH following their HIV diagnosis, resulting in 78 live births (66.1%), 18 induced abortions (15.2%), 10 pre-viable fetal losses (8.5%), and four stillbirths (3.4%). Over a cumulative follow-up duration of 3,202.1 years, the incidence rates of breast and cervical cancers were both 2.18 per 1,000 person-years. Additionally, the incidence rates of pelvic inflammatory disease, cervical intraepithelial neoplasm (above grade II), and osteoporosis were 4.67, 11.21, and 13.39 per 1,000 patient-years, respectively. Conclusion This is the first multicenter study to investigate the clinical and epidemiological characteristics of WLWH in Korea. The incidence and prevalence of diseases in women, including breast cancer, cervical cancer, and chronic comorbidities, are high in WLWH in Korea; therefore, further research and efforts are needed to manage these diseases.

Juvenile xanthogranuloma (JXG) is a rare histiocytic disorder primarily affecting children, typically presenting as self-limiting skin lesions. However, extracutaneous JXG (extra-JXG) or systemic JXG (sJXG) can involve various organs, including the central nervous system (CNS), leading to high morbidity and mortality, especially in cases of CNS involvement. Treatment approaches for CNS–JXG, including surgical resection, chemotherapy, and radiation therapy, lack consensus, with reports of relapsed or refractory cases being rare. Here, we present the case of a 2-year-old girl with refractory extra-JXG involving the CNS, characterized by multiple intracranial lesions.Initial chemotherapy with prednisolone and vinblastine showed no response, and second-line therapy, including cytarabine and vincristine combined with surgical resection, was also ineffective. However, a 6-cycle third-line chemotherapy regimen incorporating vincristine and carboplatin led to a positive response, with stable disease status, and normal growth and neurodevelopment observed. Our findings suggest that combined chemotherapy with carboplatin and vincristine is a feasible and well-tolerated treatment strategy for patients with CNS–JXG.

Background: Posterior long-segment instrumentation (PLSI) enables the stable repair of thoracolumbar fractures (TLFx) and is thus widely used. However, patients with highly unstable fractures may experience implant failure and related complications (e.g., pain and kyphosis) despite PLSI. Few studies have considered the implant failure rate and risk factors associated with PLSI for TLFx. Methods: This study reviewed 162 consecutive patients with TLFx who underwent PLSI and completed > 1 year of follow-up between April 2011 and December 2019. Implant failure was defined as rod breakage, cap dislodgement, or screw breakage. Risk factors for implant failure were evaluated by multivariate regression analysis that included demographic, injury-related, and surgical factors. Results: There were 15 cases (9.3%) of implant failure at the final follow-up (mean, 28.0 ± 18.0 months). Current smoker at the time of injury, fracture level, load sharing score, and anterior compression ratio (ACR) significantly differed between the implant failure and control groups (all p < 0.05). Multivariate logistic regression identified current smoker at the time of injury (adjusted odds ratio [aOR], 5.924; 95% CI, 1.405–24.988), mid to low lumbar fracture (aOR, 15.977; 95% CI, 4.064–62.810), and ACR (aOR, 1.061; 95% CI, 1.009–1.115) as predictors of implant failure. Conclusions This study demonstrated a high implant failure rate in patients with TLFx treated with PLSI. Smoking at the time of injury, mid to low lumbar fracture, and higher ACR were identified as significant risk factors for implant failure. These findings can help guide treatment decisions and improve patient outcomes in TLFx surgery.

Background: This study aims to investigate the trend of doctor shopping among patients with rotator cuff tear (RCT) before undergoing surgery and to examine the relevance of these findings to the public. Methods: A survey was conducted of 326 patients from 10 hospitals (male, 176; female, 150) who underwent arthroscopic rotator cuff repair (ARCR) for symptomatic RCT between September 2019 and February 2020. A questionnaire was used to obtain data regarding the type of medical care service, medical institutions visited before surgery, number of treatments received, and cost of treatment. Results: A total of 326 patients (87%) received treatment at least once at another medical institution before visiting the hospital where the surgery was performed. Patients visited an average of 9.4 health providers or physicians for shoulder pain before visiting the hospital where surgery was performed. Among the 326 patients, 148 (45%) visited more than two medical institutions and spent an average of 641,983 Korean won (KRW; $466, 50,000–5,000,000 KRW) before surgery. Medical expenses before surgery were proportional to the number of medical institutions visited (P=0.002), symptom duration (P=0.002), and initial visual analog scale (VAS) pain score (P=0.007) but were not associated with sex, age, VAS pain score immediately before surgery, or RCT size. Conclusions Medical expense before ARCR was associated with the severity of preoperative pain and duration of symptoms. After onset of shoulder symptoms, patients should visit as soon as possible a hospital that has surgeons who specialize in shoulder repair to prevent unnecessary medical expense and proper treatment.Level of evidence: IV.

Histiocytic neoplasms are rare diseases involving macrophages, dendritic cells, and monocytes. They include Langer‑ hans cell histiocytosis (LCH), Erdheim-Chester disease (ECD), Rosai-Dorfman disease (RDD), juvenile xanthogranuloma (JXG), and histiocytic sarcoma. Histiocytic neoplasms are characterized by varied clinical courses and prognoses, necessitating a nuanced understanding of their classification, epidemiology, and clinical manifestations. Genetic studies have revealed somatic mutations, predominantly in the MAPK pathway, suggesting a clonal neoplastic nature.This review covers the current understanding of histiocytic neoplasms, molecular pathophysiology, with a particular focus on mutations in genes such as BRAF, MAP2K1, and the PI3K-AKT signaling pathways, and evolving treatment strategies, especially focusing on LCH, ECD, RDD, and JXG. The treatment landscape has evolved with advancements in targeted therapies. BRAF inhibitors, such as vemurafenib and dabrafenib, have shown efficacy, especially in highrisk LCH cases; however, challenges remain, including relapse post-treatment discontinuation, and adverse effects.MEK inhibitors have also demonstrated effectiveness, and cobimetinib has recently been approved for use in adults.Further research is required to determine the optimal treatment duration and strategies for managing therapy inter‑ ruptions. Advancements in molecular genetics and targeted therapies have revolutionized the management of histio‑ cytic neoplasms. However, ongoing research is crucial for optimizing patient outcomes.

Objective: We elucidated the effect of monochorionicity on neonatal and long-term neurologic outcomes on an individual basis in triplets. Methods: We retrospectively reviewed the perinatal outcomes and development and growth at 18 to 24 months corrected age (CA) of triplets born alive between 24 and 32 weeks of gestational age (GA) between 2009 and 2021 from the Seoul National University Hospital database. Neurod­evelopmental impairment (NDI) was defined as any delay among the Bayley-III domains (motor and language), cerebral palsy, hearing impairment, or visual loss and was performed at a CA of 18 to 24 months. Results: We included 40 sets of triplets (120 infants), comprising 26, 10, and 4 sets of trichorionic (TC), dichorionic (DC), and monochorionic (MC) triplets, respectively. Ten infants, unaffected by monochorionicity out of 30 DC infants, were included in the non-MC group. Eighty-eight infants were included in the non-MC group, and 32 infants were affected by monochorionicity. In vitro fertilization-embryo transfer was more frequent in the non-MC group (P<0.05), and twin-to-twin transfusion syndrome affected only the MC group (P<0.01). At 24 months of CA, a combined delay of language and cognition in Bayley-III was evident in the MC group (P<0.05). Although NDI did not significantly differ between the 2 groups (P=0.059), the composite outcome of NDI+ postnatal death was significantly different (P<0.05). NDI+ postnatal death correlated with GA, Z-score of birth weight, brain injury, and monochorionicity in the univariate analysis (P<0.05). Multivariate analysis revealed a significant correlation between monochorionicity and NDI+ postnatal death. (P<0.05). Conclusion Monochorionicity is associated with adverse long-term neurodevelopmental out comes.

Purpose: This study compares the dosimetric properties of EBT3 and EBT4 GAFchromic films in transmission and reflection scanning modes, focusing on dose response, sensitivity, and postirradiation stability. Methods: The EBT3 and EBT4 films were irradiated at doses of 0–10 Gy using a Varian TrueBeam linear accelerator at 6 MV. The films were scanned at intervals between 1 and 336 hours after irradiation in both transmission and reflection modes. Net optical density (NetOD) values from each scan were used to evaluate dose response and sensitivity, with calibration curves created for each film and scan mode. Dose differences between calculated and delivered doses were assessed over time. Results: The EBT3 and EBT4 films exhibited similar dose–response curves and stable NetOD values across both scanning modes. However, EBT4 exhibited reduced sensitivity variability in response to dose changes. After irradiation, NetOD values increased up to 24 hours before stabilizing, suggesting that a 24-hour scan time is sufficient for consistent measurements. Dose differences between films and modes remained within ±4%. Conclusions EBT4 offers comparable dosimetric performance to EBT3, with additional benefits, such as improved dose–response linearity and reduced sensitivity fluctuations. The findings indicate that EBT4 can serve as a reliable successor to EBT3.