Background: s/Aims: Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021. Methods: Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop. Results: In November 2021, the finalized draft was presented for public scrutiny during a formal hearing. Conclusions The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Objective: To investigate whether reader training improves the performance and agreement of radiologists in interpreting unenhanced breast magnetic resonance imaging (MRI) scans using diffusion-weighted imaging (DWI). Materials and Methods: A study of 96 breasts (35 cancers, 24 benign, and 37 negative) in 48 asymptomatic women was performed between June 2019 and October 2020. High-resolution DWI with b-values of 0, 800, and 1200 sec/mm 2 was performed using a 3.0-T system. Sixteen breast radiologists independently reviewed the DWI, apparent diffusion coefficient maps, and T1-weighted MRI scans and recorded the Breast Imaging Reporting and Data System (BI-RADS) category for each breast. After a 2-h training session and a 5-month washout period, they re-evaluated the BI-RADS categories. A BI-RADS category of 4 (lesions with at least two suspicious criteria) or 5 (more than two suspicious criteria) was considered positive.The per-breast diagnostic performance of each reader was compared between the first and second reviews. Inter-reader agreement was evaluated using a multi-rater κ analysis and intraclass correlation coefficient (ICC). Results: Before training, the mean sensitivity, specificity, and accuracy of the 16 readers were 70.7% (95% confidence interval [CI]: 59.4–79.9), 90.8% (95% CI: 85.6–94.2), and 83.5% (95% CI: 78.6–87.4), respectively. After training, significant improvements in specificity (95.2%; 95% CI: 90.8–97.5; P = 0.001) and accuracy (85.9%; 95% CI: 80.9–89.8; P = 0.01) were observed, but no difference in sensitivity (69.8%; 95% CI: 58.1–79.4; P = 0.58) was observed. Regarding inter-reader agreement, the κ values were 0.57 (95% CI: 0.52–0.63) before training and 0.68 (95% CI: 0.62–0.74) after training, with a difference of 0.11 (95% CI: 0.02–0.18; P = 0.01). The ICC was 0.73 (95% CI: 0.69–0.74) before training and 0.79 (95% CI: 0.76–0.80) after training (P = 0.002). Conclusion Brief reader training improved the performance and agreement of interpretations by breast radiologists using unenhanced MRI with DWI.

Purpose: Renal tumors account for approximately 7% of all childhood cancers. These include Wilms tumor (WT), clear cell sarcoma of the kidney (CCSK), malignant rhabdoid tumor of the kidney (MRTK), renal cell carcinoma (RCC), congenital mesoblastic nephroma (CMN) and other rare tumors. We investigated the epidemiology of pediatric renal tumors in Korea. Materials and Methods: From January 2001 to December 2015, data of pediatric patients (0–18 years) newly-diagnosed with renal tumors at 26 hospitals were retrospectively analyzed. Results: Among 439 patients (male, 240), the most common tumor was WT (n=342, 77.9%), followed by RCC (n=36, 8.2%), CCSK (n=24, 5.5%), MRTK (n=16, 3.6%), CMN (n=12, 2.7%), and others (n=9, 2.1%). Median age at diagnosis was 27.1 months (range 0-225.5) and median follow-up duration was 88.5 months (range 0-211.6). Overall, 32 patients died, of whom 17, 11, 1, and 3 died of relapse, progressive disease, second malignant neoplasm, and treatment-related mortality. Five-year overall survival and event free survival were 97.2% and 84.8% in WT, 90.6% and 82.1% in RCC, 81.1% and 63.6% in CCSK, 60.3% and 56.2% in MRTK, and 100% and 91.7% in CMN, respectively (p < 0.001). Conclusion The pediatric renal tumor types in Korea are similar to those previously reported in other countries. WT accounted for a large proportion and survival was excellent. Non-Wilms renal tumors included a variety of tumors and showed inferior outcome, especially MRTK. Further efforts are necessary to optimize the treatment and analyze the genetic characteristics of pediatric renal tumors in Korea.

Purpose: The purpose of this study was to identify changes in physical activity, sleep quality, and quality of life (QOL) during COVID-19 in adults by age group. Methods: An online survey was conducted on a total of 160 participants who were divided into three groups by age; young adults, middle-aged adults, and old adults. The participants responded to the self-reported assessment of the impact of social distancing during COVID-19, International Physical Activity Questionnaire (IPAQ), Pittsburgh Sleep Quality Index (PSQI), and Short Form-36 Health Survey (SF-36). Descriptive statistics, analysis of variance, and Pearson’s correlation were used for data analysis. Results: There were significant differences between the three age groups in physical activity (p < 0.05) and PSQI (p < 0.01) and a post hoc analysis showed that the young adults’ group had significantly higher physical activity than the old adults’ group, while the old adults’ group had significantly lower scores of PSQI (better sleep quality) than the others. The young adults’ group showed a significant negative correlation between the stress from social distancing and QOL (r = -0.27, p < 0.05) and between PSQI and QOL (r = -0.48, p < 0.05). For the middle-aged adults’ group, there was a significant negative correlation between PSQI and QOL (r = -0.53, p < 0.05). The old adults’ group showed a significant negative correlation between the stress from social distancing and physical activity (r = -0.35, p < 0.05) and PSQI (r = -0.50, p < 0.05), while there was a significant positive correlation between physical activity and PSQI (r = 0.30, p < 0.05) and QOL (r = 0.30, p < 0.05). Conclusion The results of this study could be used as basic data for the promotion of physical and mental health in the post-COVID-19 era

Purpose: This study compared the subjective and objective sleep quality between subjects with and without thoracic hyper-kyphosis. Methods: Forty participants were divided into a hyper-kyphosis (n = 17) and normal group (n = 17) by thoracic spinal angle measurement. The subjective sleep quality was measured using PSQI, a self-report, and objective sleep quality was measured using an actigraphy that measures time according to sleep patterns. Results: The PSQI scores of subjects with thoracic hyper-kyphosis were significantly higher than those with normal thoracic curvature (p = 0.013). The total sleep time and real sleep time were less in subjects with hyper-kyphosis than in normal subjects (p = 0.006;p = 0.029). The light sleep time was less in subjects with excessive spondylolisthesis than in normal subjects (p = 0.010). Light sleep time was less in those with hyper-kyphosis, but deep sleep time was similar to the subjects with a normal thoracic curvature (p = 0.003;p = 0.140). Conclusion Subjects with thoracic hyper-kyphosis had a decrease in subjective sleep quality, such as sleep discomfort, and objective sleep quality, such as a decrease in sleep time compared to normal subjects.

Purpose: This study examined the effects of social distancing in COVID-19 on musculoskeletal problems and the quality of life. Methods: One hundred and thirty-five subjects participated in this study and responded to an online survey on stress from the social distancing in COVID-19, computer and smartphone usages, musculoskeletal pain, and quality of life. The stress from social distancing was assessed by a Visual Analogue Scale (VAS). The Neck Disability Index (NDI), Oswestry Disability Index (ODI), and Boston Carpal Tunnel Questionnaire (BCTQ) were provided to assess the musculoskeletal pain, and Short Form-36 (SF-36) was provided to assess the quality of life. Frequency analysis, descriptive statistics, Pearson’s correlation coefficient, and independent t-test were used for data analysis. Results: Statistically significant, but low positive correlation stress from the social distancing (VAS) and NDI (r=0.19, p<0.05) and ODI (r=0.18, p<0.05), and negative correlation between stress from the social distancing (VAS) and SF-36 (r=-0.17, p<0.05). The NDI score was significantly greater in the group with high stress than in the group with low stress from social distancing (p<0.05). Conclusion This study is meaningful in that it evaluated, through the physical therapy approaches, the potential side-effects on physical and mental health in various social changes caused by COVID-19. The results of this study may be used as basic data in future studies related to COVID-19.

Purpose: This study examined the effects of social distancing in COVID-19 on musculoskeletal problems and the quality of life. Methods: One hundred and thirty-five subjects participated in this study and responded to an online survey on stress from the social distancing in COVID-19, computer and smartphone usages, musculoskeletal pain, and quality of life. The stress from social distancing was assessed by a Visual Analogue Scale (VAS). The Neck Disability Index (NDI), Oswestry Disability Index (ODI), and Boston Carpal Tunnel Questionnaire (BCTQ) were provided to assess the musculoskeletal pain, and Short Form-36 (SF-36) was provided to assess the quality of life. Frequency analysis, descriptive statistics, Pearson’s correlation coefficient, and independent t-test were used for data analysis. Results: Statistically significant, but low positive correlation stress from the social distancing (VAS) and NDI (r=0.19, p<0.05) and ODI (r=0.18, p<0.05), and negative correlation between stress from the social distancing (VAS) and SF-36 (r=-0.17, p<0.05). The NDI score was significantly greater in the group with high stress than in the group with low stress from social distancing (p<0.05). Conclusion This study is meaningful in that it evaluated, through the physical therapy approaches, the potential side-effects on physical and mental health in various social changes caused by COVID-19. The results of this study may be used as basic data in future studies related to COVID-19.

Background: Hereditary hemolytic anemia (HHA) is a rare disease characterized by premature red blood cell (RBC) destruction due to intrinsic RBC defects. The RBC Disorder Working Party of the Korean Society of Hematology established and updated the standard operating procedure for making an accurate diagnosis of HHA since 2007. The aim of this study was to investigate a nationwide epidemiology of Korean HHA. Methods: We collected the data of a newly diagnosed pediatric HHA cohort (2007–2016) and compared this cohort's characteristics with those of a previously surveyed pediatric HHA cohort (1997–2006) in Korea. Each participant's information was retrospectively collected by a questionnaire survey. Results: A total of 369 children with HHA from 38 hospitals distributed in 16 of 17 districts of Korea were investigated. RBC membranopathies, hemoglobinopathies, RBC enzymopathies, and unknown etiologies accounted for 263 (71.3%), 59 (16.0%), 23 (6.2%), and 24 (6.5%) of the cases, respectively. Compared to the cohort from the previous decade, the proportions of hemoglobinopathies and RBC enzymopathies significantly increased (P < 0.001 and P = 0.008, respectively). Twenty-three of the 59 hemoglobinopathy patients had immigrant mothers, mostly from South-East Asia. Conclusion In Korea, thalassemia traits have increased over the past 10 years, reflecting both increased awareness of this disease and increased international marriages. The enhanced recognition of RBC enzymopathies is due to advances in diagnostic technique; however, 6.5% of HHA patients still do not have a clear diagnosis. It is necessary to improve accessibility of diagnosing HHA.

Background: Hodgkin's lymphoma (HL) constitutes 10%–20% of all malignant lymphomas and has a high cure rate (5-year survival, around 90%). Recently, interest has increased concerning preventing secondary complications (secondary cancer, endocrine disorders) in long-term survivors. We aimed to study the epidemiologic features and therapeutic outcomes of HL in children, adolescents, and young adults in Korea. Methods: We performed a multicenter, retrospective study of 224 patients aged < 25 years diagnosed with HL at 22 participating institutes in Korea from January 2007 to August 2016. Results: A higher percentage of males was diagnosed at a younger age. Nodular sclerosis histopathological HL subtype was most common, followed by mixed cellularity subtype.Eighty-one (36.2%), 101 (45.1%), and 42 (18.8%) patients were classified into low, intermediate, and high-risk groups, respectively. Doxorubicin, bleomycin, vinblastine, dacarbazine was the most common protocol (n = 102, 45.5%). Event-free survival rate was 86.0% ± 2.4%, while five-year overall survival (OS) rate was 96.1% ± 1.4%: 98.7% ± 1.3%, 97.7% ± 1.6%, and 86.5% ± 5.6% in the low, intermediate, and high-risk groups, respectively (P = 0.021). Five-year OS was worse in patients with B-symptoms, stage IV disease, highrisk, splenic involvement, extra-nodal lymphoma, and elevated lactate dehydrogenase level.In multivariate analysis, B-symptoms and extra-nodal involvement were prognostic factors for poor OS. Late complications of endocrine disorders and secondary malignancy were observed in 17 and 6 patients, respectively. Conclusion This is the first study on the epidemiology and treatment outcomes of HL in children, adolescents, and young adults in Korea. Future prospective studies are indicated to develop therapies that minimize treatment toxicity while maximizing cure rates in children, adolescents, and young adults with HL.