Purpose: The aim of this study is to compare the detection ability of quality of life (QoL) changes and responsiveness of the KOrean QUality of life in Stomach cancer patients Study group (KOQUSS)-40 and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ). Materials and Methods: A multicenter prospective observational study was conducted to evaluate QoL changes after various gastrectomies between January 2021 and April 2022. Participants were instructed to complete the KOQUSS-40 and EORTC QLQ-C30/STO22 preoperatively and at 1, 3, 6, and 12 months postoperatively. QoL changes over time and QoL responsiveness were assessed for each questionnaire. Results: Data from 491 patients who underwent curative gastrectomy for gastric cancer at 22 institutions were analyzed. The summary scores of the KOQUSS-40 and EORTC QLQ-STO22 showed significant differences between the total and proximal gastrectomy groups (p=0.044 and p=0.038, respectively), but no difference was observed for the EORTC QLQ-C30. Dysphagia on the KOQUSS-40 was significantly different between the total and proximal gastrectomy groups (p=0.031); however, dysphagia on the EORTC QLQ-STO22 did not differ. The responsiveness of the KOQUSS-40 was similar to that of the EORTC QLQ in patients who experienced ≥ 10% body weight loss, but approximately 10% less in patients receiving adjuvant chemotherapy than the EORTC QLQ. Conclusion KOQUSS-40 has several advantages over EORTC QLQ-C30/STO22 when comparing QoL between the total and proximal gastrectomy groups. The findings provide information for researchers investigating the QoL of patients who have undergone curative gastrectomy for gastric cancer.

Background/Aims: Biliary tract cancer (BTC) is a rare malignancy with poor prognosis. We investigated genomic determinants of clinical benefit from gemcitabine, cisplatin, and nab-paclitaxel (GAP) versus gemcitabine and cisplatin (GC) in advanced BTC. Methods: Clinical and genomic data using TruSight Oncology 500 were analyzed from patients treated with GAP (N=198) or GC (N=89) as first-line therapy. Results: With a median follow-up of 33.0 months, GAP modestly improved progression-free survival (PFS) (hazard ratio [HR] 0.764; 95% confidence interval [CI] 0.591–0.989) without significant overall survival (OS) difference compared to GC. Genomic profiling revealed frequent alterations in TP53 (35.2%), KRAS (16.4%), SMAD4 (10.5%), and TNFRSF14 (10.5%), involving RTK/RAS (44.3%), TP53 (41.8%), and PI3K (20.2%) pathways. Single-gene mutations did not predict treatment benefit. However, pathway-level analysis identified PI3K pathway activation as significantly associated with inferior PFS (HR 2.148; 95% CI 1.478–3.124) and OS (HR 2.096; 95% CI 1.413–3.109) in patients receiving GAP, an effect not observed with GC. Importantly, GAP conferred clinical benefit only in patients without PI3K pathway activation, while no survival advantage was seen in those with such alterations (Pinteraction=0.023 for PFS, Pinteraction=0.003 for OS). Similar results were obtained in the independent validation cohort treated with GAP (N=103) or GC (N=64) for BTC. Conclusions Genomic profiling using next-generation sequencing identified PI3K pathway activation as key molecular determinant that differentiates patient outcomes between GAP and GC treatments in advanced BTC.

Purpose: This retrospective cohort study aimed to investigate the association between the use of pain medications with varying cyclooxygenase-2 (COX-2) selectivity and the incidence of endometriosis (EMS) in women. Materials and Methods: Medical records from January 1, 1994, to December 31, 2022, were retrospectively analyzed. The cohort included 33406 patients diagnosed with any pain-related condition who were prescribed either selective COX-2 inhibitors or nonsteroidal anti-inflammatory drugs (NSAIDs). Patients were followed for up to 5 years from the cohort entry date. The incidence of EMS was compared between the two medication groups using Cox proportional hazards models, adjusting for confounding factors such as age, past drug use, and prior diagnosis. Results: The incidence rates of EMS were 3.00 per 1000 person-years in the COX-2 inhibitor group and 3.97 per 1000 person-years in the NSAIDs group. After adjustment for confounders, the hazard ratio for EMS incidence in the COX-2 inhibitor group compared to the NSAIDs group was 0.77 [95% confidence interval (CI), 0.63 to 0.93; p<0.01], indicating a significantly lower risk in the COX-2 inhibitor group. Subgroup analysis revealed that this association was particularly significant in younger women aged 20– 44 years, with a hazard ratio of 0.71 (95% CI, 0.54 to 0.95; p<0.05) in this age group. Conclusion The findings suggest that COX-2 inhibitors may reduce the incidence of EMS compared to traditional NSAIDs, highlighting their potential as a strategic option for managing EMS, particularly among younger women. Further prospective studies are needed to confirm these findings.

Objective: To establish local diagnostic reference levels (DRLs) for pediatric neck CT based on age, weight, and water-equivalent diameter (WED) across multiple university hospitals in South Korea. Materials and Methods: This retrospective study analyzed pediatric neck CT examinations from nine university hospitals, involving patients aged 0–18 years. Data were categorized by age, weight, and WED, and radiation dose metrics, including volume CT dose index (CTDIvol) and dose length product, were recorded. Data retrieval and analysis were conducted using a commercially available dose-management system (Radimetrics, Bayer Healthcare). Local DRLs were established following the International Commission on Radiological Protection guidelines, using the 75th percentile as the reference value. Results: A total of 1159 CT examinations were analyzed, including 169 scans from Institution 1, 132 from Institution 2, 126 from Institution 3, 129 from Institution 4, 128 from Institution 5, 105 from Institution 6, 162 from Institution 7, 127 from Institution 8, and 81 from Institution 9. Radiation dose metrics increased with age, weight, and WED, showing significant variability both within and across institutions. For patients weighing less than 10 kg, the DRL for CTDIvol was 5.2 mGy. In the 10–19 kg group, the DRL was 5.8 mGy; in the 20–39 kg group, 7.6 mGy; in the 40–59 kg group, 11.0 mGy; and for patients weighing 60 kg or more, 16.2 mGy. DRLs for CTDIvol by age groups were as follows: 5.3 mGy for infants under 1 year, 5.7 mGy for children aged 1–4 years, 7.6 mGy for ages 5–9 years, 11.2 mGy for ages 10–14 years, and 15.6 mGy for patients 15 years or older. Conclusion Local DRLs for pediatric neck CT were established based on age, weight, and WED across nine university hospitals in South Korea.

Purpose: This retrospective cohort study aimed to investigate the association between the use of pain medications with varying cyclooxygenase-2 (COX-2) selectivity and the incidence of endometriosis (EMS) in women. Materials and Methods: Medical records from January 1, 1994, to December 31, 2022, were retrospectively analyzed. The cohort included 33406 patients diagnosed with any pain-related condition who were prescribed either selective COX-2 inhibitors or nonsteroidal anti-inflammatory drugs (NSAIDs). Patients were followed for up to 5 years from the cohort entry date. The incidence of EMS was compared between the two medication groups using Cox proportional hazards models, adjusting for confounding factors such as age, past drug use, and prior diagnosis. Results: The incidence rates of EMS were 3.00 per 1000 person-years in the COX-2 inhibitor group and 3.97 per 1000 person-years in the NSAIDs group. After adjustment for confounders, the hazard ratio for EMS incidence in the COX-2 inhibitor group compared to the NSAIDs group was 0.77 [95% confidence interval (CI), 0.63 to 0.93; p<0.01], indicating a significantly lower risk in the COX-2 inhibitor group. Subgroup analysis revealed that this association was particularly significant in younger women aged 20– 44 years, with a hazard ratio of 0.71 (95% CI, 0.54 to 0.95; p<0.05) in this age group. Conclusion The findings suggest that COX-2 inhibitors may reduce the incidence of EMS compared to traditional NSAIDs, highlighting their potential as a strategic option for managing EMS, particularly among younger women. Further prospective studies are needed to confirm these findings.

Background and Objectives: The Fractional Flow Reserve and Intravascular UltrasoundGuided Intervention Strategy for Clinical Outcomes in Patients with Intermediate Stenosis (FLAVOUR) trial demonstrated non-inferiority of fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) compared with intravascular ultrasound (IVUS)-guided PCI. We sought to investigate the cost-effectiveness of FFR-guided PCI compared to IVUS-guided PCI in Korea. Methods: A 2-part cost-effectiveness model, composed of a short-term decision tree model and a long-term Markov model, was developed for patients who underwent PCI to treat intermediate stenosis (40% to 70% stenosis by visual estimation on coronary angiography).The lifetime healthcare costs and quality-adjusted life-years (QALYs) were estimated from the healthcare system perspective. Transition probabilities were mainly referred from the FLAVOUR trial, and healthcare costs were mainly obtained through analysis of Korean National Health Insurance claims data. Health utilities were mainly obtained from the Seattle Angina Questionnaire responses of FLAVOUR trial participants mapped to EQ-5D. Results: From the Korean healthcare system perspective, the base-case analysis showed that FFR-guided PCI was 2,451 U.S. dollar lower in lifetime healthcare costs and 0.178 higher in QALYs compared to IVUS-guided PCI. FFR-guided PCI remained more likely to be cost-effective over a wide range of willingness-to-pay thresholds in the probabilistic sensitivity analysis. Conclusions Based on the results from the FLAVOUR trial, FFR-guided PCI is projected to decrease lifetime healthcare costs and increase QALYs compared with IVUS-guided PCI in intermediate coronary lesion, and it is a dominant strategy in Korea.

Purpose: Cystic duct cancers (CDCs) have been classified as extrahepatic bile duct cancers or gallbladder cancers (GBCs); however, it is unclear whether their clinical behavior is similar to that of distal extrahepatic bile duct cancers (DBDCs) or GBCs. Materials and Methods: T category of the CDCs was classified using current T category scheme of the GBCs and DBDCs, and clinicopathological factors were compared among 38 CDCs, 345 GBCs, and 349 DBDCs. We modified Nakata’s classifications (type 1, confined within cystic duct [CD]; combined types 2-4, extension beyond CD) and compared them. Results: No significant overall survival (OS) difference was observed between the patients with CDC, GBC, and DBDC. The T category of GBC staging was more accurate at distinguishing OS in patients with CDC than the DBDC staging. Patients with T3 CDC and GBC showed a significant OS difference when using the T category for GBC staging, while those with T1-T2 CDC and GBC showed no significant difference. In contrast, the T category of DBDC staging did not show any significant OS difference between patients with T1-T2 CDC and DBDC or T3 CDC and DBDC. Patients with type 1 CDC had significantly better OS than those with combined types. Conclusion Unlike GBCs and DBDCs, CDCs exhibit distinct clinicopathological characteristics. The OS is better when the CDC confines within the CD, compared to when it extends beyond it. Therefore, we propose a new T category scheme (T1, confined to CD; T2, invaded beyond CD) for better classifying CDCs.

Objective: To establish local diagnostic reference levels (DRLs) for pediatric neck CT based on age, weight, and water-equivalent diameter (WED) across multiple university hospitals in South Korea. Materials and Methods: This retrospective study analyzed pediatric neck CT examinations from nine university hospitals, involving patients aged 0–18 years. Data were categorized by age, weight, and WED, and radiation dose metrics, including volume CT dose index (CTDIvol) and dose length product, were recorded. Data retrieval and analysis were conducted using a commercially available dose-management system (Radimetrics, Bayer Healthcare). Local DRLs were established following the International Commission on Radiological Protection guidelines, using the 75th percentile as the reference value. Results: A total of 1159 CT examinations were analyzed, including 169 scans from Institution 1, 132 from Institution 2, 126 from Institution 3, 129 from Institution 4, 128 from Institution 5, 105 from Institution 6, 162 from Institution 7, 127 from Institution 8, and 81 from Institution 9. Radiation dose metrics increased with age, weight, and WED, showing significant variability both within and across institutions. For patients weighing less than 10 kg, the DRL for CTDIvol was 5.2 mGy. In the 10–19 kg group, the DRL was 5.8 mGy; in the 20–39 kg group, 7.6 mGy; in the 40–59 kg group, 11.0 mGy; and for patients weighing 60 kg or more, 16.2 mGy. DRLs for CTDIvol by age groups were as follows: 5.3 mGy for infants under 1 year, 5.7 mGy for children aged 1–4 years, 7.6 mGy for ages 5–9 years, 11.2 mGy for ages 10–14 years, and 15.6 mGy for patients 15 years or older. Conclusion Local DRLs for pediatric neck CT were established based on age, weight, and WED across nine university hospitals in South Korea.

Purpose: This retrospective cohort study aimed to investigate the association between the use of pain medications with varying cyclooxygenase-2 (COX-2) selectivity and the incidence of endometriosis (EMS) in women. Materials and Methods: Medical records from January 1, 1994, to December 31, 2022, were retrospectively analyzed. The cohort included 33406 patients diagnosed with any pain-related condition who were prescribed either selective COX-2 inhibitors or nonsteroidal anti-inflammatory drugs (NSAIDs). Patients were followed for up to 5 years from the cohort entry date. The incidence of EMS was compared between the two medication groups using Cox proportional hazards models, adjusting for confounding factors such as age, past drug use, and prior diagnosis. Results: The incidence rates of EMS were 3.00 per 1000 person-years in the COX-2 inhibitor group and 3.97 per 1000 person-years in the NSAIDs group. After adjustment for confounders, the hazard ratio for EMS incidence in the COX-2 inhibitor group compared to the NSAIDs group was 0.77 [95% confidence interval (CI), 0.63 to 0.93; p<0.01], indicating a significantly lower risk in the COX-2 inhibitor group. Subgroup analysis revealed that this association was particularly significant in younger women aged 20– 44 years, with a hazard ratio of 0.71 (95% CI, 0.54 to 0.95; p<0.05) in this age group. Conclusion The findings suggest that COX-2 inhibitors may reduce the incidence of EMS compared to traditional NSAIDs, highlighting their potential as a strategic option for managing EMS, particularly among younger women. Further prospective studies are needed to confirm these findings.