Objective: To evaluate the diagnostic performance of the “probable hepatocellular carcinoma (HCC)” category in the Korean Liver Cancer Association-National Cancer Center (KLCA-NCC) v2022 guidelines. Materials and Methods: This multicenter retrospective study included patients at risk of HCC who underwent gadoxetic acid-enhanced MRI between January 2015 and June 2018; a subgroup of these patients also underwent liver CT. Eligible patients had at least one non-cystic lesion (≥10 mm) with a reference standard. Four radiologists interpreted the images independently and the results were pooled. The performance of “definite HCC” and “probable HCC” together and “probable HCC” alone were compared between v2018 and v2022. Results: A total of 2,237 patients (1,666 men; mean age, 59 ± 11 years) with 2,445 lesions were included. In v2022, 1.5% (143/9,780) of the lesions were additionally categorized as “probable HCC” by four reviewers on MRI; among these, 104 lesions were not HCCs. Focal nodular hyperplasia (FNH) or FNH-like nodules constituted 90.4% (94/104) of the false positives. When “definite HCC” and “probable HCC” were combined, v2022 showed higher sensitivity (83.7% [5,670/6,776] vs. 83.1% [5,631/6,776]) but lower specificity (77.1% [2,316/3,004] vs. 80.6% [2,420/3,004]) than v2018 (P < 0.001). For “probable HCC” alone, v2022 showed a lower positive predictive value (PPV) than v2018 (64.1% [373/582] vs. 76.1% [334/439], P < 0.001). In v2022, lesions with non-rim arterial-phase hyperenhancement (APHE) showed a lower PPV than those without APHE (42.3% [91/215] vs. 76.8% [282/367], P < 0.001). In the CT subgroup (n = 1,590), 1.6% (99/6,360) of the lesions were reassessed as “probable HCC,” and its PPV was 83.8% (83/99) in v2022 whereas no lesions were classified as “probable HCC” under v2018. Conclusion The revised “probable HCC” category in the KLCA-NCC v2022 aligns with updates in the diagnostic flow, demonstrating acceptable performance on MRI and CT. Notably, FNH or FNH-like nodules can be misclassified as “probable HCC” when MRI is used.

Cardiovascular disease is an important risk factor for mortality among kidney transplant recipients. In this study, we aimed to investigate the association between cardiovascular risk score at kidney transplantation and long-term outcomes of patients. Methods: In this prospective, observational cohort study, we enrolled kidney transplant recipients who participated in the Korean Organ Transplantation Registry and underwent transplantation between April 2014 and December 2019. The cardiovascular risk status of kidney transplant recipients was assessed using the Framingham risk score. All-cause mortality, major adverse cardiovascular events, allograft failure, estimated glomerular filtration rates (eGFRs), and composite outcomes were evaluated after kidney transplantation. Results: Of the 4,682 kidney transplant recipients, 96 died during 30.7 ± 19.1 months of follow-up. The Kaplan-Meier survival analysis results showed that high Framingham risk scores were associated with all-cause mortality, major adverse cardiovascular events, and composite outcomes. According to the multivariable Cox analysis, high Framingham risk scores were associated with an increased risk of mortality (hazard ratio [HR], 3.20; 95% confidence interval [CI], 1.30–7.91), major adverse cardiovascular events (HR, 8.43; 95% CI, 2.41–29.52), and composite outcomes (HR, 2.05; 95% CI, 1.19–3.46). The eGFRs after transplantation were significantly higher among patients in the low Framingham risk score group (p < 0.001). However, Framingham risk scores were not associated with graft loss or rapid decline in eGFRs. Conclusion: The Framingham risk score is a useful indicator of cardiovascular events, mortality, and kidney function after kidney transplantation.

Living kidney donors with hypertension are potential candidates for solving the donor shortages in renal transplantation. However, the safety of donors with hypertension after nephrectomy has not been sufficiently confirmed. Methods: A total of 642 hypertensive and 4,848 normotensive living kidney donors who were enrolled in the Korean Organ Transplantation Registry between May 2014 and December 2020 were included in this study. The study endpoints were a decreased estimated glomerular filtration rate (eGFR) and proteinuria. Results: In the entire cohort, donors with hypertension had a lower eGFR before nephrectomy in comparison to normotensive donors which remained lower after kidney transplantation. The incidence of proteinuria in hypertensive donors increased during follow-up. In propensity score-matched analysis, the risk of eGFR being <60 mL/min/1.73 m2 (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.50–1.19) or <45 mL/min/1.73 m2 (HR, 0.50; 95% CI, 0.06–4.03) was not significantly increased in donors with hypertension. However, hypertensive donors were found to have a significantly higher risk of proteinuria than normotensive donors (HR, 2.28; 95% CI, 1.05–4.94). Similar findings were also observed in the analysis of the entire cohort, indicating that hypertensive donors had a significantly higher risk of proteinuria (adjusted HR, 1.77; 95% CI, 1.10–2.85), without a substantial increase in the risk of decreased renal function. Conclusion: The risk of proteinuria after donation was substantially increased in donors with hypertension. These findings underscore the need for careful monitoring of proteinuria in hypertensive donors following donation.

Background: Although insulin resistance is common, its significance in kidney transplant recipients remains unclear. We explored clinical implications of the triglyceride-glucose (TyG) index as a marker for unfavorable allograft outcomes in kidney transplant recipients. Methods: A total of 6,354 kidney transplant recipients were enrolled in a multicenter prospective cohort study between May 2014 and December 2022. The TyG index was assessed between 6 and 12 months after transplantation. We evaluated the association between the TyG index and the risk of adverse kidney outcomes. Results: The cumulative rates of ≥50% decline in estimated glomerular filtration rate (eGFR), death-censored graft survival, and major adverse kidney events differed across TyG index quartiles, with the highest rate observed in quartile 4 (p < 0.001). TyG index quartile 4 was associated with the highest risk of death-censored graft loss after multivariable adjustment (adjusted hazard ratio, 2.13; 95% confidence interval [CI], 1.28–3.55). The risk of ≥30% decline in eGFR was 1.46 times higher (95% CI, 1.17–1.82) in quartile 4 compared with quartile 1, and the risk of ≥50% decline was 1.78 times higher (95% CI, 1.30–2.44). Quartile 4 also showed a significantly steeper decline in renal function, with an adjusted mean difference in eGFR slope of –4.72 mL/min/1.73 m2 (95% CI, –7.39 to –2.04). Conclusion Kidney transplant recipients with high TyG index were at increased risk of eGFR decline and graft loss, and also exhibited a more rapid deterioration in renal function. The TyG index is a useful marker for identifying individuals at high risk for adverse graft outcomes.

Background: Posttransplant diabetes mellitus (PTDM) complicates kidney transplant recipients (KTRs) in morbidity and mortality. This study aimed to predict PTDM risk in KTRs using machine learning and deep learning models. Methods: Data were obtained from the Korea Organ Transplantation Registry, a nationwide cohort study of KTRs. Four machine learning algorithms, including eXtreme Gradient Boosting (XGBoost), CatBoost, light gradient boosting machine and logistic regression, and deep learning were implemented on 41 pretransplant and 31 posttransplant variables to predict PTDM. Model performance was assessed using the area under the curve (AUC) of the receiver operating characteristic curve, accuracy, precision, recall, and F1 score. Results: Among 3,213 KTRs, 497 patients (15.5%) developed PTDM within 1 year. The PTDM group had higher age, body mass index (BMI), triglyceride level, and prevalence of hypertension and cardiovascular disease, and lower total cholesterol level at baseline than the No-PTDM group. The XGBoost model showed the highest AUC (0.738) and F1 score (0.42), and modest accuracy (0.86), while the CatBoost model exhibited the highest accuracy (0.87) and precision (0.79). Feature importance in XGBoost was highest for recipient age, followed by baseline BMI, triglyceride level at posttransplant 6 months, baseline glycated hemoglobin and high-density lipoprotein cholesterol level, white blood cell (WBC) count and serum uric acid level at 6 months, baseline WBC count, and tacrolimus trough level at discharge. Conclusion The XGBoost model demonstrated the best performance for predicting PTDM within 1 year, offering an accurate tool for early identification and personalized care of high-risk KTRs for PTDM.

Purpose: Surveillance guidelines following breast cancer surgery recommend mammography as the sole imaging modality. However, the accuracy of mammography is low in younger women and in those with dense breast tissue. Additional imaging modalities, such as ultrasonography and magnetic resonance imaging (MRI), may offer diagnostic benefits.This prospective, multicenter study (KBCSG-27) aims to compare the diagnostic performances of mammography, ultrasonography, and MRI for detecting second breast cancer (SBC) in women with a personal history of breast cancer (PHBC) and dense breasts. Methods This study will recruit approximately 1,756 women, aged 20–75 years, who were treated for stage 0–III breast cancer and have dense breast tissue on mammography.Participants will undergo two annual breast screenings, each consisting of mammography, ultrasonography, and MRI. MRI will be performed using either abbreviated magnetic resonance imaging (AB-MRI) or full-protocol magnetic resonance imaging (FP-MRI), which will be randomly assigned such that each participant receives both protocols alternately.Radiologists will independently interpret all images. A combination of pathology results and 12-month follow-up will serve as the reference standard. A patient-reported outcome (PRO) tool will be used to assess patients’ experiences and preferences between AB-MRI and FPMRI. The primary objective is to compare the cancer detection rates of ultrasonography versus AB-MRI and ultrasonography versus FP-MRI. Secondary outcomes include comparisons of the invasive cancer detection rates, abnormal interpretation rates, sensitivity, specificity, positive and negative predictive values, accuracy, and interval cancer rates. Subgroup analyses will be conducted based on age, menopausal status, mammographic breast density, and molecular subtype. Additionally, PRO results of AB-MRI and FP-MRI will be compared.Discussion: This ongoing, prospective, multicenter study aims to evaluate the performance of ultrasonography, AB-MRI, and FP-MRI in SBC surveillance in women with PHBC and dense breasts. Enrollment is expected to be completed by 2025, with results anticipated after 2028.

Objective: To assess whether performing exercises during hemodialysis reduces the risk of developing intradialytic hypotension and enhances exercise capacity in patients with chronic kidney disease. Methods: This study included patients aged ≥18 years undergoing hemodialysis. Participants performed exercises using a portable lower extremity ergometer during hemodialysis sessions for 3 weeks. Data regarding walking distance, knee strength, quality of life, fat-free mass, arterial pressure, blood pressure, heart rate, frequency of intradialytic hypotension, fatigue, and duration of hemodialysis were collected and analyzed. Results: Significant improvements in walking distance and knee strength were observed following the implementation of exercise training during hemodialysis. Although there was no significant reduction in the frequency of intradialytic hypotension, a decreasing trend was noted. Other parameters such as quality of life and fatigue did not show significant changes. Conclusion Using a portable ergometer during hemodialysis improved exercise capacity and knee strength in patients with chronic kidney disease. There was a trend toward reduced intradialytic hypotension, suggesting potential cardiovascular benefits. Further research with larger sample sizes is needed to confirm these findings.

Cytomegalovirus (CMV) is the most important opportunistic viral pathogen in solid organ transplant (SOT) recipients.The Korean guideline for the prevention of CMV infection in SOT recipients was developed jointly by the Korean Society for Infectious Diseases and the Korean Society of Transplantation. CMV serostatus of both donors and recipients should be screened before transplantation to best assess the risk of CMV infection after SOT. Seronegative recipients receiving organs from seropositive donors face the highest risk, followed by seropositive recipients. Either antiviral prophylaxis or preemptive therapy can be used to prevent CMV infection. While both strategies have been demonstrated to prevent CMV infection post-transplant, each has its own advantages and disadvantages. CMV serostatus, transplant organ, other risk factors, and practical issues should be considered for the selection of preventive measures. There is no universal viral load threshold to guide treatment in preemptive therapy. Each institution should define and validate its own threshold.Valganciclovir is the favored agent for both prophylaxis and preemptive therapy. The evaluation of CMV-specific cellmediated immunity and the monitoring of viral load kinetics are gaining interest, but there was insufficient evidence to issue recommendations. Specific considerations on pediatric transplant recipients are included.

Background: The management of dental plaque and the appropriate use of oral hygiene tools are crucial for oral health. Withincreasing interest in oral health care, various oral hygiene products are available on the market. As the most basic oral hygiene tool, the large-head toothbrush has gained significant consumer interest. This study evaluates the suitability of large-head toothbrushes as oral hygiene tools by comparing their efficacy with that of regular-sized toothbrushes. Methods: We evaluated the efficacy of large-head and regular-sized toothbrushes. The amount of dental plaque before and afterbrushing was measured using quantitative light-induced fluorescence digital (QLF-D) images and the plaque index (PI) in adult participants with more than 28 teeth (n=15/group). After brushing, the collected toothbrushes were rinsed 10 times in clean water, thoroughly dried, and weighed on an electronic scale. Data were analyzed using the Wilcoxon signed-rank test with SPSS Statistics Version 29.0. Results: QLF-D analysis showed a significant decrease in fluorescence intensity scores after use of a regular-sized toothbrush,whereas the scores after use of a large-head toothbrush were not significantly reduced. PI measurements indicated significant reductions in dental plaque for both head types. However, detailed analysis by tooth surface revealed that the regular-sized toothbrush significantly reduced plaque on the proximal, palatal/lingual, and labial/buccal surfaces. In contrast, the large-head toothbrush only showed significant reductions in place on the proximal and palatal/lingual surfaces, not on the labial/buccal surface. Additionally, compared to the regular-sized toothbrush, the large-head toothbrush retained more toothpaste residue despite similar cleaning efforts after brushing. Conclusion Compared to the regular-sized toothbrush, the large-head toothbrush showed lower overall efficacy in dentalplaque removal. The results of this study provide significant information regarding the use of large-head toothbrushes.

Objectives: The purpose of this study was to estimate the financial cost required for dental health care coverage by integrating North Korea’s free medical care system and South Korea’s health insurance system, assuming the unification of North and South Korea. Methods: North Korea’s health insurance and medical benefit finances were estimated based on the benefit content, benefit target, benefit level, dental service utilization rate, and dental care cost growth rate. Results: The results of the financial estimate assuming an average annual growth rate of dental medical expenses of 5% were as follows. Assuming that the proportion of health insurance recipients was 0% and the proportion of medical benefit recipients was 100%, health insurance was estimated at 0 won and government spending on medical benefits was estimated at KRW 771.9 billion in 2022. Assuming that the proportion of health insurance beneficiaries was 97% and the proportion of medical benefit recipients was 3%, health insurance was estimated at KRW 8,241.3 billion and government expenditure on medical benefits was estimated at KRW 510.9 billion in 2052. In addition, the financial estimation results assuming an average annual growth rate of dental medical expenses of 10% were as follows. Assuming that the proportion of health insurance recipients was 0% and the proportion of medical benefit recipients was 100%, health insurance was estimated at 0 won and government spending on medical benefits was estimated at KRW 808.7 billion in 2022.Assuming that the rate of health insurance beneficiaries was 97% and the rate of medical benefit recipients was 3%, health insurance was estimated at KRW 34.858 trillion and government spending on medical benefits was estimated at KRW 2.1608 trillion in 2052. Conclusions If the rate of increase in dental medical expenditure is not controlled, it is possible that very high dental medical expenditure will become a significant social burden for both North and South Korea. A strategy needs to be developed to minimize the financial impact after unification and promote efficient integration of the dental healthcare system.