Objective: Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors combined with endocrine therapy (ET) constitute the standard systemic treatment for estrogen receptor-positive, human epidermal growth factor 2-negative (ER+/HER2-) metastatic breast cancer (MBC). However, treatment responses remain heterogeneous, highlighting the need for reliable prognostic markers. This study aimed to evaluate the prognostic significance of 18F-fluorodeoxyglucose (FDG) PET/CT findings in this setting. Materials and Methods: This retrospective single-center cohort study included patients with ER+/HER2- MBC who underwent18F-FDG PET/CT before initiating CDK4/6 inhibitors plus ET between 2018 and 2023. Maximum standardized uptake value(SUVmax), whole-body metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured. Progression-free survival (PFS) and overall survival (OS) were evaluated as the primary and secondary outcomes, respectively, using multivariable Cox models. PET parameters (SUVmax, MTV, and TLG) were analyzed as both continuous and dichotomized variables based on median values, adjusting for relevant clinical covariates. Results: Among the 374 patients, 82 (21.9%) presented with de novo metastatic disease, and 357 (95.5%) received CDK4/6 inhibitors as first-line therapy. In multivariable Cox analysis, all continuous PET parameters were independently associated with PFS (adjusted hazard ratio for SUVmax 1.05 [95% confidence interval 1.02–1.08]; log-transformed MTV 1.16 [1.08–1.25]; and log-transformed TLG 1.14 [1.07–1.23]) and OS (SUVmax 1.08 [1.04–1.11]; log-transformed MTV 1.24 [1.12–1.38]; and log-transformed TLG 1.22 [1.11–1.34]) with all P < 0.001. Results based on dichotomized PET parameters were similar to those obtained with continuous values: PFS (adjusted hazard ratio for SUVmax ≥ 7.6, 1.41 [1.08–1.85]; MTV ≥ 21.2 cm 3 , 1.41 [1.08–1.86]; and TLG ≥ 78.9, 1.51 [1.14–1.99]) with P ≤ 0.013 and OS (1.43 [1.01–2.04]; 1.84 [1.28– 2.66]; and 1.73 [1.20–2.50], respectively) with P ≤ 0.046. Conclusion Pretreatment 18F-FDG PET/CT parameters are independent prognostic markers in patients with ER+/HER2- MBC receiving CDK4/6 inhibitors with ET, supporting their potential utility in risk stratification.

Background: Barriers to treatment with intravenous thrombolysis (IVT) for patients with acute ischemic stroke (AIS) in South Korea remain incompletely characterized. We analyze a nationwide prospective cohort to determine patient-level features associated with delayed presentation and non-treatment of potential IVT-eligible patients. Methods: We identified consecutive patients with AIS from 01/2011 to 08/2023 from a multicenter and prospective acute stroke registry in Korea. Patients were defined as IVT candidates if they presented within 4.5 hours from the last known well, had no lab evidence of coagulopathy, and had National Institute of Health Stroke Scale (NIHSS) ≥ 4. Multivariable generalized linear mixed regression models were used to investigate the associations between their characteristics and the IVT candidates or the use of IVT among the candidates. Results: Among 84,103 AIS patients, 41.0% were female, with a mean age of 69 ± 13 years and presentation NIHSS of 4 [interquartile range, 1–8]. Out of these patients, 13,757 (16.4%) were eligible for IVT, of whom 8,179 (59.5%) received IVT. Female sex (adjusted risk ratio [RR], 0.90; 95% confidence interval [CI], 0.86–0.94) and lower years of education (adjusted RR, 0.90; 95% CI, 0.84–0.97 for 0–3 years, compared to ≥ 13 years) were associated with a decreased likelihood of presenting as eligible for IVT after AIS; meanwhile, young age (adjusted RR, 1.12; 95% CI, 1.01–1.24 for ≤ 44 years, compared to 75–84 years) was associated with an increased likelihood of being an IVT candidate. Among those who were eligible for IVT, only age was significantly associated with the use of IVT (adjusted RR, 1.09; 95% CI, 1.03–1.16 for age 65–74 and adjusted RR, 0.83; 95% CI, 0.76–0.90 for ≥ 85 years, respectively). Conclusion Most patients with AIS present outside IVT eligibility in South Korea, and only 60% of eligible patients were ultimately treated. We identified increased age, female sex and lower education as key features on which to focus interventions for improving IVT utilization.

Background: Barriers to treatment with intravenous thrombolysis (IVT) for patients with acute ischemic stroke (AIS) in South Korea remain incompletely characterized. We analyze a nationwide prospective cohort to determine patient-level features associated with delayed presentation and non-treatment of potential IVT-eligible patients. Methods: We identified consecutive patients with AIS from 01/2011 to 08/2023 from a multicenter and prospective acute stroke registry in Korea. Patients were defined as IVT candidates if they presented within 4.5 hours from the last known well, had no lab evidence of coagulopathy, and had National Institute of Health Stroke Scale (NIHSS) ≥ 4. Multivariable generalized linear mixed regression models were used to investigate the associations between their characteristics and the IVT candidates or the use of IVT among the candidates. Results: Among 84,103 AIS patients, 41.0% were female, with a mean age of 69 ± 13 years and presentation NIHSS of 4 [interquartile range, 1–8]. Out of these patients, 13,757 (16.4%) were eligible for IVT, of whom 8,179 (59.5%) received IVT. Female sex (adjusted risk ratio [RR], 0.90; 95% confidence interval [CI], 0.86–0.94) and lower years of education (adjusted RR, 0.90; 95% CI, 0.84–0.97 for 0–3 years, compared to ≥ 13 years) were associated with a decreased likelihood of presenting as eligible for IVT after AIS; meanwhile, young age (adjusted RR, 1.12; 95% CI, 1.01–1.24 for ≤ 44 years, compared to 75–84 years) was associated with an increased likelihood of being an IVT candidate. Among those who were eligible for IVT, only age was significantly associated with the use of IVT (adjusted RR, 1.09; 95% CI, 1.03–1.16 for age 65–74 and adjusted RR, 0.83; 95% CI, 0.76–0.90 for ≥ 85 years, respectively). Conclusion Most patients with AIS present outside IVT eligibility in South Korea, and only 60% of eligible patients were ultimately treated. We identified increased age, female sex and lower education as key features on which to focus interventions for improving IVT utilization.

Background: Barriers to treatment with intravenous thrombolysis (IVT) for patients with acute ischemic stroke (AIS) in South Korea remain incompletely characterized. We analyze a nationwide prospective cohort to determine patient-level features associated with delayed presentation and non-treatment of potential IVT-eligible patients. Methods: We identified consecutive patients with AIS from 01/2011 to 08/2023 from a multicenter and prospective acute stroke registry in Korea. Patients were defined as IVT candidates if they presented within 4.5 hours from the last known well, had no lab evidence of coagulopathy, and had National Institute of Health Stroke Scale (NIHSS) ≥ 4. Multivariable generalized linear mixed regression models were used to investigate the associations between their characteristics and the IVT candidates or the use of IVT among the candidates. Results: Among 84,103 AIS patients, 41.0% were female, with a mean age of 69 ± 13 years and presentation NIHSS of 4 [interquartile range, 1–8]. Out of these patients, 13,757 (16.4%) were eligible for IVT, of whom 8,179 (59.5%) received IVT. Female sex (adjusted risk ratio [RR], 0.90; 95% confidence interval [CI], 0.86–0.94) and lower years of education (adjusted RR, 0.90; 95% CI, 0.84–0.97 for 0–3 years, compared to ≥ 13 years) were associated with a decreased likelihood of presenting as eligible for IVT after AIS; meanwhile, young age (adjusted RR, 1.12; 95% CI, 1.01–1.24 for ≤ 44 years, compared to 75–84 years) was associated with an increased likelihood of being an IVT candidate. Among those who were eligible for IVT, only age was significantly associated with the use of IVT (adjusted RR, 1.09; 95% CI, 1.03–1.16 for age 65–74 and adjusted RR, 0.83; 95% CI, 0.76–0.90 for ≥ 85 years, respectively). Conclusion Most patients with AIS present outside IVT eligibility in South Korea, and only 60% of eligible patients were ultimately treated. We identified increased age, female sex and lower education as key features on which to focus interventions for improving IVT utilization.

Background: Barriers to treatment with intravenous thrombolysis (IVT) for patients with acute ischemic stroke (AIS) in South Korea remain incompletely characterized. We analyze a nationwide prospective cohort to determine patient-level features associated with delayed presentation and non-treatment of potential IVT-eligible patients. Methods: We identified consecutive patients with AIS from 01/2011 to 08/2023 from a multicenter and prospective acute stroke registry in Korea. Patients were defined as IVT candidates if they presented within 4.5 hours from the last known well, had no lab evidence of coagulopathy, and had National Institute of Health Stroke Scale (NIHSS) ≥ 4. Multivariable generalized linear mixed regression models were used to investigate the associations between their characteristics and the IVT candidates or the use of IVT among the candidates. Results: Among 84,103 AIS patients, 41.0% were female, with a mean age of 69 ± 13 years and presentation NIHSS of 4 [interquartile range, 1–8]. Out of these patients, 13,757 (16.4%) were eligible for IVT, of whom 8,179 (59.5%) received IVT. Female sex (adjusted risk ratio [RR], 0.90; 95% confidence interval [CI], 0.86–0.94) and lower years of education (adjusted RR, 0.90; 95% CI, 0.84–0.97 for 0–3 years, compared to ≥ 13 years) were associated with a decreased likelihood of presenting as eligible for IVT after AIS; meanwhile, young age (adjusted RR, 1.12; 95% CI, 1.01–1.24 for ≤ 44 years, compared to 75–84 years) was associated with an increased likelihood of being an IVT candidate. Among those who were eligible for IVT, only age was significantly associated with the use of IVT (adjusted RR, 1.09; 95% CI, 1.03–1.16 for age 65–74 and adjusted RR, 0.83; 95% CI, 0.76–0.90 for ≥ 85 years, respectively). Conclusion Most patients with AIS present outside IVT eligibility in South Korea, and only 60% of eligible patients were ultimately treated. We identified increased age, female sex and lower education as key features on which to focus interventions for improving IVT utilization.

Artificial intelligence (AI) has expanded rapidly into various medical fields, such as the orthopedic surgery field. The exponential growth of medical big data, advances in computational power, and sophisticated algorithms have facilitated the integration of AI into clinical practice.AI applications in orthopedic surgery include accurate disease classification, precise imaging analysis, and patient-specific outcome predictions. Recent studies highlight the effectiveness of AI models in classifying the severity of osteoarthritis using the Kellgren-Lawrence grading system and accurately predicting postoperative transfusion requirements. AI-driven deep learning techniques have shown superior performance in analyzing complex medical imaging, surpassing traditional diagnostic methods. Thus, AI enhances diagnostic precision and offers personalized therapeutic strategies. AI in orthopedic surgery has already emerged opening a new frontier in patient care and clinical outcomes.

Purpose: Although advancements in medical treatments have been made, approximately half of patients with intestinal Crohn’s disease (CD) require intestinal resections during their lifetime. It is well-known that the nutritional status of CD patients can impact postoperative morbidity. The objective of this study was to evaluate the clinical significance of prognostic nutritional index (PNI) in patients with intestinal CD who underwent primary bowel resection. Materials and Methods: We retrospectively investigated patients who were diagnosed with CD and underwent intestinal surgery at Severance Hospital between January 2005 and October 2018. The patients were divided into two groups: PNI ≤40 (n=150) and PNI >40 (n=77). We assessed the clinical significance of PNI in terms of the incidence of postoperative infectious complications (PICs) and the postoperative recurrence of CD. Results: The low PNI group had significantly higher rates of infectious complications (32.0% vs. 10.4%, p=0.001) compared to the high PNI group. Multivariable analysis identified low PNI (≤40) and longer operation time (>180 min) as independent risk factors associated with PICs [odds ratio (OR)=2.754, 95% confidence interval (CI)=1.140–6.649, p=0.024; OR=2.986, 95% CI=1.451–6.143, p=0.003]. PICs were significantly associated with surgical recurrence (hazard ratio=2.217, 95% CI=1.064–4.617, p=0.034). Conclusion Preoperative PNI could serve as a predictive factor for PICs in CD patients who undergo intestinal resection. Additionally, PICs are significantly associated with a higher risk of surgical recurrence in CD.

Background: As the importance of meniscus in joint function becomes more apparent, there is a growing interest in meniscus repair techniques. Notably, biological augmentation methods have shown promising results for meniscus healing, despite their challenges in practical implementation. The purpose of this study was to evaluate meniscus healing and clinical outcomes of meniscus repair with bone marrow aspirate for horizontal or radial tears. Methods: This study retrospectively reviewed patients who underwent arthroscopic meniscal repair with bone marrow aspirate from the iliac crest. A total of 30 patients with horizontal or radial meniscus tears confirmed by magnetic resonance imaging (MRI) were included, excluding those with insufficient data or concurrent surgeries. Patient demographic characteristics, operative data, and clinical outcomes including pain numeric rating scale, International Knee Documentation Committee score, Lysholm score, and Tegner activity scale were evaluated. For radiographic evaluation, knee x-rays, preoperative MRIs, and postoperative 3-month MRIs were evaluated. Results: Thirty patients (15 women and 15 men) with a mean age of 46.8 ± 15.2 years were followed up for a mean of 25.1 ± 3.4 months. Of these patients, 22 (73%) had horizontal meniscal tears, while 8 (27%) had radial tears. Clinical outcomes were significantly improved over the time from the initial to 2 years after surgery. Meniscus healing was 60% on MRI at 3 months after surgery. There was no correlation between changes in clinical scores and healing rate. Furthermore, there was no statistically significant difference in the healing rate or changes in clinical scores according to tear patterns. Retears were observed in 2 patients, who were non-compliant with rehabilitation and were managed conservatively. Conclusions Augmentation with bone marrow aspirate harvested from the iliac crest for meniscal repair of horizontal or radial tears yields favorable healing rates in MRI and clinical outcomes, highlighting its potential for addressing challenging meniscal repair.

Purpose: Robot-assisted surgery is readily applied to every type of colorectal surgeries. However, studies showing the safety and feasibility of robotic surgery (RS) have dealt with rectal cancer more than colon cancer. This study aimed to investigate how technical advantages of RS can translate into actual clinical outcomes that represent postoperative systemic response. Methods: This study retrospectively reviewed consecutive cases in a single tertiary medical center in Korea. Patients with primary colon cancer who underwent curative resection between 2006 and 2012 were included. Propensity score matching was done to adjust baseline patient characteristics (age, sex, body mass index, American Society of Anesthesiologists physical status, tumor profile, pathologic stage, operating surgeon, surgery extent) between open surgery (OS), laparoscopic surgery (LS), and RS groups. Results: After propensity score matching, there were 66 patients in each group for analysis, and there was no significant differences in baseline patient characteristics. Maximal postoperative leukocyte count was lowest in the RS group and highest in the OS group (P=0.021). Similar results were observed for postoperative neutrophil count (P=0.024). Postoperative prognostic nutritional index was highest in the RS group and lowest in the OS group (P<0.001). The time taken to first flatus and soft diet resumption was longest in the OS group and shortest in the RS group (P=0.001 and P<0.001, respectively). Among all groups, other short-term postoperative outcomes such as hospital stay and complications did not show significant difference, and oncological survival results were similar. Conclusion Better postoperative inflammatory indices in the RS group may correlate with their faster recovery of bowel motility and diet resumption compared to LS and OS groups.

Purpose: Robot-assisted surgery is readily applied to every type of colorectal surgeries. However, studies showing the safety and feasibility of robotic surgery (RS) have dealt with rectal cancer more than colon cancer. This study aimed to investigate how technical advantages of RS can translate into actual clinical outcomes that represent postoperative systemic response. Methods: This study retrospectively reviewed consecutive cases in a single tertiary medical center in Korea. Patients with primary colon cancer who underwent curative resection between 2006 and 2012 were included. Propensity score matching was done to adjust baseline patient characteristics (age, sex, body mass index, American Society of Anesthesiologists physical status, tumor profile, pathologic stage, operating surgeon, surgery extent) between open surgery (OS), laparoscopic surgery (LS), and RS groups. Results: After propensity score matching, there were 66 patients in each group for analysis, and there was no significant differences in baseline patient characteristics. Maximal postoperative leukocyte count was lowest in the RS group and highest in the OS group (P=0.021). Similar results were observed for postoperative neutrophil count (P=0.024). Postoperative prognostic nutritional index was highest in the RS group and lowest in the OS group (P<0.001). The time taken to first flatus and soft diet resumption was longest in the OS group and shortest in the RS group (P=0.001 and P<0.001, respectively). Among all groups, other short-term postoperative outcomes such as hospital stay and complications did not show significant difference, and oncological survival results were similar. Conclusion Better postoperative inflammatory indices in the RS group may correlate with their faster recovery of bowel motility and diet resumption compared to LS and OS groups.