In patients with differentiated thyroid cancer (DTC), initial recurrence risk stratification based on clinical, histopathological, and perioperative data remains the key determinant for guiding management strategies during the first 1-2 years post-treatment. However, the adoption of ongoing risk stratification (ORS), which dynamically reassesses risk by integrating longitudinal clinical data and treatment response, enables more precise long-term prognostic assessment and facilitates highly individualized management. Building upon recent guidelines, the 2026 KTA guideline has been further refined by incorporating robust evidence from large-scale national cohorts and comprehensive systematic reviews. These updated recommendations outline contemporary concepts of ORS, risk-adapted TSH suppression targets, optimized surveillance modalities for recurrence detection, and disease-specific long-term follow-up strategies. Reflecting the paradigm shift toward de-escalated treatment, this revision integrates evolved perspectives on TSH suppression intensity, the clinical interpretation of thyroglobulin levels, and tailored follow-up intervals. These evidence-based recommendations aim to minimize unnecessary treatment and excessive surveillance in the large proportion of patients with excellent prognosis after initial therapy, while ensuring that each patient receives appropriately tailored and effective long-term management.

Background: Ensuring reference material (RM) commutability is crucial for evaluating measurement traceability in order to standardize laboratory tests. However, commutability assessment is not routinely performed. We assessed whether RMs prepared following CLSI C37-A guidelines could be used without assessing commutability by evaluating their commutability for four lipid measurements using the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) and CLSI EP14 protocols. Methods: We analyzed total cholesterol (TC), triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in frozen sera from 20 individuals and 11 RMs, prepared by the Korea Disease Control and Prevention AgencyLaboratory Standardization Project (per CLSI C37-A), using six routine measurement procedures (MPs). Regression equations and 95% prediction intervals derived from single-donor sera were analyzed following CLSI EP14. The IFCC protocol was used to assess differences in inter-MP biases between RM and clinical samples. The effect of the TG concentration on commutability was evaluated by analyzing biases between MP results and reference procedure-assigned values. Results: RMs were commutable for most MP pairs for TC and TG. Commutability for HDL-C and LDL-C varied across RMs, with RM10 and RM11 showing higher TG levels (2.38 and 2.95 mmol/L, respectively) and lower commutability. Increased bias percentages from assigned values were observed for RMs with higher TG levels. Conclusions RMs prepared per CLSI C37-A were commutable with most MP pairs for TC and TG. Elevated TG levels affected HDL-C and LDL-C commutability, highlighting the need to consider TG concentrations during RM preparation and assess commutability to standardize laboratory tests.

Purpose: This report offers a detailed examination of the inception and current state of the Heavy-ion Therapy Center (HITC) at the Yonsei Cancer Center (YCC), setting it apart as the world’s first center equipped with a fixed beam and two superconducting gantries for carbon-ion radiation therapy (CIRT). Materials and Methods: Preparations for CIRT at YCC began in 2013; accordingly, this center has completed a decade of meticulous planning and culminating since the operational commencement of the HITC in April 2023. Results: This report elaborates on the clinical preparation for adopting CIRT in Korea. It includes an extensive description of HITC’s facility layout at YCC, which comprises the accelerator and treatment rooms. Furthermore, this report delineates the clinical workflow, criteria for CIRT application, and the rigorous quality assurance processes implemented at YCC. It highlights YCC’s sophisticated radiation therapy infrastructure, collaborative initiatives, and the efficacious treatment of >200 prostate cancer cases utilizing CIRT. Conclusion This manuscript concludes by discussing the prospective influence of CIRT on the medical domain within Korea, spotlighting YCC’s pioneering contribution and forecasting the widespread integration of this groundbreaking technology.

Purpose: This report offers a detailed examination of the inception and current state of the Heavy-ion Therapy Center (HITC) at the Yonsei Cancer Center (YCC), setting it apart as the world’s first center equipped with a fixed beam and two superconducting gantries for carbon-ion radiation therapy (CIRT). Materials and Methods: Preparations for CIRT at YCC began in 2013; accordingly, this center has completed a decade of meticulous planning and culminating since the operational commencement of the HITC in April 2023. Results: This report elaborates on the clinical preparation for adopting CIRT in Korea. It includes an extensive description of HITC’s facility layout at YCC, which comprises the accelerator and treatment rooms. Furthermore, this report delineates the clinical workflow, criteria for CIRT application, and the rigorous quality assurance processes implemented at YCC. It highlights YCC’s sophisticated radiation therapy infrastructure, collaborative initiatives, and the efficacious treatment of >200 prostate cancer cases utilizing CIRT. Conclusion This manuscript concludes by discussing the prospective influence of CIRT on the medical domain within Korea, spotlighting YCC’s pioneering contribution and forecasting the widespread integration of this groundbreaking technology.

Maternally inherited diabetes and deafness (MIDD) is a rare mitochondrial disorder primarily resulting from m.3243A>G mutation. The clinical characteristics of MIDD exhibit significant heterogeneity. Our study aims to delineate these characteristics and determine the potential correlation with m.3243A>G heteroplasmy levels. This retrospective, descriptive study encompassed patients with confirmed m.3243A>G mutation and diabetes mellitus at Seoul National University Hospital. Our cohort comprises 40 patients with MIDD, with a mean age at study enrollment of 33.3±12.9 years and an average % of heteroplasmy of 30.0%± 14.6% in the peripheral blood. The most prevalent comorbidity was hearing loss (90%), followed by albuminuria (61%), seizure (38%), and stroke (33%). We observed a significant negative correlation between % of heteroplasmy and age at diabetes diagnosis. These clinical features can aid in the suspicion of MIDD and further consideration of genetic testing for m.3243A>G mutation.

FAM19A5, a novel secretory protein highly expressed in the brain, is potentially associated with the progression of Alzheimer's disease (AD). However, its role in the AD pathogenesis remains unclear. Here, we investigated the potential function of FAM19A5 in the context of AD. We generated APP/PS1 mice with partial FAM19A5 deficiency, termed APP/PS1/FAM19A5+/LacZ mice. Compared with control APP/PS1 mice, APP/PS1/FAM19A5+/LacZ mice exhibited significantly lower Aβ plaque density and prolonged the lifespan of the APP/PS1 mice. To further explore the therapeutic potential of targeting FAM19A5, we developed a FAM19A5 antibody. Administration of this antibody to APP/PS1 mice significantly improved their performance in the Y-maze and passive avoidance tests, indicating enhanced cognitive function. This effect was replicated in 5XFAD mice, a model of early-onset AD characterized by rapid Aβ accumulation. Additionally, FAM19A5 antibody treatment in 5XFAD mice led to enhanced exploration of novel objects and increased spontaneous alternation behavior in the novel object recognition and Y-maze tests, respectively, indicating improved cognitive function. These findings suggest that FAM19A5 plays a significant role in AD pathology and that targeting with FAM19A5 antibodies may be a promising therapeutic strategy for AD.

Purpose: Advances in chemotherapeutic and targeted agents have increased pathologic complete response (pCR) rates after neoadjuvant systemic therapy (NST). Vacuum-assisted biopsy (VAB) has been suggested to accurately evaluate pCR. This study aims to confirm the non-inferiority of the 5-year disease-free survival of patients who omitted breast surgery when predicted to have a pCR based on breast magnetic resonance imaging (MRI) and VAB after NST, compared with patients with a pCR who had undergone breast surgery in previous studies. Methods The Omission of breast surgery for PredicTed pCR patients wIth MRI and vacuumassisted bIopsy in breaST cancer after neoadjuvant systemic therapy (OPTIMIST) trial is a prospective, multicenter, single-arm, non-inferiority study enrolling in 17 tertiary care hospitals in the Republic of Korea. Eligible patients must have a clip marker placed in the tumor and meet the MRI criteria suggesting complete clinical response (post-NST MRI size ≤ 1 cm and lesion-to-background signal enhancement ratio ≤ 1.6) after NST. Patients will undergo VAB, and breast surgery will be omitted for those with no residual tumor. Axillary surgery can also be omitted if the patient was clinically node-negative before and after NST and met the stringent criteria of MRI size ≤ 0.5 cm. Survival and efficacy outcomes are evaluated over five years.Discussion: This study seeks to establish evidence for the safe omission of breast surgery in exceptional responders to NST while minimizing patient burden. The trial will address concerns about potential undertreatment due to false-negative results and recurrence as well as improved patient-reported quality of life issues from the omission of surgery. Successful completion of this trial may reshape clinical practice for certain breast cancer subtypes and lead to a safe and less invasive approach for selected patients.

Objectives: This study uses the short-form Center for Epidemiological Studies-Depression Scale (CES-D) to screen for depression among Korean career soldiers, aiming to protect mental health and ensure military stability. Methods: The study involves 2922 career soldiers who completed online self-report questionnaires assessing suicidality, depression, anxiety, and social support. Diagnosis of major depressive episodes (MDEs) using the Korean version of the Mini International Neuropsychiatric Interview (K-MINI) was confirmed through Pearson correlation analysis of the 20 CES-D items. The top three correlated items form the Depression Screening Questionnaire for Korean Career soldiers (DSQ-KC). Receiver operating characteristic curves and area under the curve (AUC) values were obtained, with the DSQ-KC total score as the explanatory variable and MDEs as the response variable. Independent t-tests were performed to determine whether suicidality, anxiety, and social support differed based on the cut-off scores of the DSQ-KC. Results: In the analysis of each CES-D item with an MDE diagnosis, items 4, 6, and 3 were obtained. The AUC value was 0.958. At a cut-off score of 2, sensitivity and specificity were 93.9% and 89.9%, respectively, with positive and negative predictive values of 14.7% and 99.6%, respectively. Conversely, at a cut-off score of 3, sensitivity and specificity were 83.7% and 94.4%, respectively, with positive and negative predictive values of 27.7% and 98.9%, respectively. Associations with suicidality, anxiety, and use of social networks from cut-off scores of 2 or 3 were examined. Conclusion The DSQ-KC, developed with three reliable items, is user-friendly and can be utilized in suicide prevention projects for career soldiers.

Purpose: To assess the impact of toxoplasma immunoglobulin G (IgG) titers on the diagnosis of active ocular toxoplasmosis. Methods: We retrospectively analyzed the medical records of patients tested for toxoplasma IgG at our uveitis clinic. Active ocular toxoplasmosis was clinically diagnosed based on wide-angle fundus photography and disease progression. Patients with IgG titers ≥ 30 IU/mL were classified as seropositive-high titer, those with IgG titers of 1.6-30 IU/mL as seropositive-low titer, and the remaining patients as seronegative. We compared the proportion of active ocular toxoplasmosis among these groups. Additionally, we evaluated the sensitivity and specificity of each titer and attempted to determine an ideal reference titer for toxoplasma IgG in diagnosing active ocular toxoplasmosis. Results: Out of 824 patients, 86 (10.4%), 88 (10.7%), and 650 (78.9%) were categorized as seropositive-high titer, seropositivelow titer, and seronegative, respectively. Among these patients, 34 in the seropositive-high titer group and 2 in the seropositive- low titer group were clinically diagnosed with active ocular toxoplasmosis. The false-positive rate was significantly different between the groups, being 60.5% in the seropositive-high titer group and 97.7% in the seropositive-low titer group (p < 0.001). The receiver operating characteristic curve indicated that 37.70 IU/mL could be an ideal reference titer for diagnosing ocular toxoplasmosis. Conclusions The false-positive rate was notably lower (60.5%) in patients with IgG titers ≥ 30 IU/mL compared to those with titers of 1.6-30 IU/mL (97.7%). Therefore, not only the presence of IgG but also the level of titer appears to be important in diagnosing ocular toxoplasmosis.

Objective: This study was performed to evaluate the efficacy and safety of lurasidone (160 mg/day) compared to quetiapine XR (QXR; 600 mg/day) in the treatment of acutely psychotic patients with schizophrenia. Methods: Patients were randomly assigned to 6 weeks of double-blind treatment with lurasidone 160 mg/day (n=105) or QXR 600 mg/day (n=105). Primary efficacy measure was the change from baseline to week 6 in Positive and Negative Syndrome Scale (PANSS) total score and Clinical Global Impressions severity (CGI-S) score. Adverse events, body measurements, and laboratory parameters were assessed. Results: Lurasidone demonstrated non-inferiority to QXR on the PANSS total score. Adjusted mean±standard error change at week 6 on the PANSS total score was -26.42±2.02 and -27.33±2.01 in the lurasidone and QXR group, respectively. The mean difference score was -0.91 (95% confidence interval -6.35–4.53). The lurasidone group showed a greater reduction in PANSS total and negative subscale on week 1 and a greater reduction in end-point CGI-S score compared to the QXR group. Body weight, body mass index, and waist circumference in the lurasidone group were reduced, with significantly lower mean change compared to QXR. Endpoint changes in glucose, cholesterol, triglycerides, and low-density lipoprotein levels were also significantly lower. The most common adverse drug reactions with lurasidone were akathisia and nausea. Conclusion Lurasidone 160 mg/day was found to be non-inferior to QXR 600 mg/day in the treatment of schizophrenia with comparable efficacy and tolerability. Adverse effects of lurasidone were generally tolerable, and beneficial effects on metabolic parameters can be expected.