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Distinguishing between pathologic complete response and residual cancer after neoadjuvant chemotherapy (NAC) is crucial for treatment decisions, but the current imaging methods face challenges. To address this, we developed deep-learning models using post-NAC dynamic contrast-enhanced MRI and clinical data. A total of 852 women with human epidermal growth factor receptor 2 (HER2)-positive or triple-negative breast cancer were randomly divided into a training set (n = 724) and a validation set (n = 128). A 3D convolutional neural network model was trained on the training set and validated independently. The main models were developed using cropped MRI images, but models using uncropped whole images were also explored. The delayed-phase model demonstrated superior performance compared to the early-phase model (area under the receiver operating characteristic curve [AUC] = 0.74 vs. 0.69, P = 0.013) and the combined model integrating multiple dynamic phases and clinical data (AUC = 0.74 vs. 0.70, P = 0.022). Deep-learning models using uncropped whole images exhibited inferior performance, with AUCs ranging from 0.45 to 0.54. Further refinement and external validation are necessary for enhanced accuracy. [ABSTRACT FROM AUTHOR]

Background/Objectives: The aim of this study was to investigate the effect of a custom neck collar with negative sensory feedback for the treatment of torticollis that was previously unresponsive to conservative or surgical treatment. Methods: Twenty-four children diagnosed with unresponsive or intractable torticollis were enrolled in this two-stage, single-arm study. The ipsilateral aspect of the orthosis is adjustable in height and designed to provide support between the clavicle and the mandibular angle on the tilted side. In stage 1 (the adjustment period), the orthosis with a smooth surface was applied for 2 h per day for 3 months. In stage 2, a rough surface with a hook-and-loop fastener (Velcro©) was attached to the collar, and it was worn for a further 2 h a day for 3 months. Twenty children (mean age 63.95 ± 13.44 months) were included in the analysis. Results: The mean torticollis angle was 17.60 ± 5.65° (mean ± SD) at baseline; 14.15 ± 3.62° directly after stage 1; and 6.00 ± 3.67° directly after stage 2 (X2 = 36.685, df = 19, p = 0.000). Conclusions: This study demonstrated the feasibility, therapeutic effect, and safety of a novel tactile feedback orthosis for the treatment of children with torticollis. The use of a custom neck collar with negative sensory feedback may be a viable therapeutic option for the treatment of unresolved or intractable torticollis. [ABSTRACT FROM AUTHOR]

The clinical and genetic characteristics of SYNGAP1 mutations in Korean pediatric patients are not well understood. We retrospectively analyzed 13 individuals with SYNGAP1 mutations from a longitudinal aspect. Clinical data, genetic profiles, and electroencephalography (EEG) patterns were examined. Genotypic analyses included gene panels and whole‐exome sequencing. All patients exhibited global developmental delay from early infancy, with motor development eventually reaching independent ambulation by 3 years of age. Language developmental delay varied significantly from nonverbal to simple sentences, which plateaued in all patients. Patients with the best language outcomes typically managed 2–3‐word sentences, corresponding to a developmental age of 2–3 years. Epilepsy developed in 77% of patients, with onset consistently following developmental delays at a median age of 31 months. Longitudinal EEG data revealed a shift from occipital to frontal epileptiform discharges with age, suggesting a correlation with synaptic maturation. These findings suggest that the critical developmental plateau occurs between the ages of 2 and 5 years and is potentially influenced by epilepsy. By analyzing longitudinal data, our study contributes to a deeper understanding of SYNGAP1‐related DEE, provides potential EEG biomarkers, and underlines the importance of early diagnosis and intervention to address this complex disorder. [ABSTRACT FROM AUTHOR]

Objectives: Cancer is a life-changing experience, and side effects from treatment can make it difficult for survivors to return to their pre-cancer "normal life." We explored the "new normal" and barriers to achieving it among lung cancer survivors who underwent surgery. Methods: Semi-structured interviews were conducted with 32 recurrence-free non–small cell lung cancer survivors. We asked survivors how life had changed; how they defined the "new normal"; barriers that prevent them from achieving a "normal" life; and unmet needs or support for normalcy. Thematic analysis was performed. Results: Defining "new normal" subjectively depends on an individual's expectation of recovery: (1) being able to do what they want without pain or discomfort; (2) being able to do activities they could accomplish before their surgery; and (3) being able to work, earn money, and support their family. We found that (1) persistent symptoms, (2) fear of cancer recurrence, (3) high expectations in recovery, and (4) psychosocial stress and guilty feelings were barriers to achieving a "new normal." The needs and support for normalcy were information on expected trajectories, postoperative management, and support from family and society. Significance of results: Survivors defined the "new normal" differently, depending on their expectations for recovery. Informing survivors about the "new normal" so they could expect possible changes and set realistic goals for their life after cancer. Health professionals need to communicate with survivors about expectations for "normality" from the beginning of treatment, and it should be included in comprehensive survivorship care. [ABSTRACT FROM AUTHOR]

Background: While breast ultrasound (US) is a useful tool for diagnosing breast masses, it can entail false‐positive biopsy results because of some overlapping features between benign and malignant breast masses and subjective interpretation. Purpose: To evaluate the performance of conductivity imaging for reducing false‐positive biopsy results related to breast US, as compared to diffusion‐weighted imaging (DWI) and abbreviated MRI consisting of one pre‐ and one post‐contrast T1‐weighted imaging. Study Type: Prospective. Subjects: Seventy‐nine women (median age, 44 years) with 86 Breast Imaging Reporting and Data System (BI‐RADS) category 4 masses as detected by breast US. Field Strength/Sequence: 3‐T, T2‐weighted turbo spin echo sequence, DWI, and abbreviated contrast‐enhanced MRI (T1‐weighted gradient echo sequence). Assessment: US‐guided biopsy (reference standard) was obtained on the same day as MRI. The maximum and mean conductivity parameters from whole and single regions of interest (ROIs) were measured. Apparent diffusion coefficient (ADC) values were obtained from an area with the lowest signal within a lesion on the ADC map. The performance of conductivity, ADC, and abbreviated MRI for reducing false‐positive biopsies was evaluated using the following criteria: lowest conductivity and highest ADC values among malignant breast lesions and BI‐RADS categories 2 or 3 on abbreviated MRI. Statistical Tests: One conductivity parameter with the maximum area under the curve (AUC) from receiver operating characteristics was selected. A P‐value <0.05 was considered statistically significant. Results: US‐guided biopsy revealed 65 benign lesions and 21 malignant lesions. The mean conductivity parameter of the single ROI method was selected (AUC = 0.74). Considering conductivity (≤0.10 S/m), ADC (≥1.60 × 10−3 mm2/sec), and BI‐RADS categories 2 or 3 reduced false‐positive biopsies by 23% (15 of 65), 38% (25 of 65), and 43% (28 of 65), respectively, without missing malignant lesions. Data Conclusion: Conductivity imaging may show lower performance than DWI and abbreviated MRI in reducing unnecessary biopsies. Evidence Level: 2 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

Purpose: Tubulinopathy represents a group of disorders caused by variants in tubulin genes, which present with a wide spectrum of brain malformations. This study was conducted to provide insight into the phenotypic and genetic spectra of tubulinopathy within the Korean pediatric population. Methods: Among individuals who underwent genetic testing at a pediatric neurology clinic between June 2011 and December 2021, 15 patients with tubulin gene variants were retrospectively recruited. Clinical features, genetic information, and brain imaging findings were retrospectively reviewed. Results: The genetic spectra of the patients included TUBA1A (n=5, 33.3%), TUBB4A (n=6, 40.0%), TUBB3 (n=2, 13.3%), TUBB (n=1, 6.7%), and TUBB2A (n=1, 6.7%) variants. Two novel mutations were identified: a c.497A>G; p.(Lys166Arg) variant in TUBA1A and a c.907G>C; p.(Ala303Pro) variant in TUBB. All 15 patients exhibited developmental delays, with a broad spectrum of severity. Other common manifestations included microcephaly (n=10; 66.7%) and seizures (n=9; 60%). A review of the neuroimaging data revealed a range of findings that were both genotype-specific and overlapping across genotypes. In cases of TUBA1A mutation (n=5), four patients (80%) presented with pachygyria and polymicrogyria, while three (60%) displayed cerebellar hypoplasia and dysplasia. All patients with TUBB4A variants (n=6) exhibited hypomyelination, and three (50%) had cerebellar dysplasia. Conclusion: This study represents the first cohort analysis of tubulin gene mutations associated with tubulinopathy in a Korean pediatric population. It suggests that these mutations can produce a broad spectrum of neurodevelopmental and neuroimaging findings and should be considered within the differential diagnosis in relevant clinical scenarios. [ABSTRACT FROM AUTHOR]

Background: Myeloperoxidase (MPO) and human neutrophil lipocalin or neutrophil gelatinase-associated lipocalin (HNL/NGAL) are stored in neutrophil granulocytes and secreted upon activation of the cells. They have been proposed to reflect the degree of inflammation in the airways. However, their role as potential markers of disease severity in childhood asthma remains unknown. This study investigated the relationship between the expression of MPO and HNL/NGAL and childhood asthma., Methods: A total of 83 pediatric patients with asthma and 59 controls were enrolled. Using enzyme-linked immunosorbent assays, the human MPO and HNL/NGAL levels were measured in sputum supernatants. Assessments including spirometry, methacholine challenge test, and atopy test were conducted., Results: No difference in sputum neutrophil counts was observed between pediatric patients with asthma and controls. However, sputum MPO and HNL/NGAL levels were significantly higher in patients with asthma than in controls (p = 0.021 and p < 0.001, respectively), especially in patients with moderate-to-severe persistent asthma. In patients with asthma, sputum MPO and HNL/NGAL levels showed a positive correlation with sputum neutrophil counts (MPO, r = 0.433, p < 0.001; HNL/NGAL, r = 0.584, p < 0.001) and with each other (r = 0.628, p < 0.001). Moreover, sputum HNL/NGAL level demonstrated better ability to accurately reflect current pulmonary function, airway inflammation, and limitations than MPO level in this study., Conclusions: Sputum MPO and HNL/NGAL levels, which reflect neutrophil activation in airways, were increased in pediatric patients with asthma. Moreover, sputum MPO and HNL/NGAL may serve as appropriate assessment indicators of asthma severity in pediatric patients., (© 2024. The Author(s).)

Objective: To develop a nomogram that integrates clinical-pathologic and imaging variables to predict ipsilateral breast tumor recurrence (IBTR) in women with ductal carcinoma in situ (DCIS) treated with breast-conserving surgery (BCS)., Materials and Methods: This retrospective study included consecutive women with DCIS who underwent BCS at two hospitals. Patients who underwent BCS between 2003 and 2016 in one hospital and between 2005 and 2013 in another were classified into development and validation cohorts, respectively. Twelve clinical-pathologic variables (age, family history, initial presentation, nuclear grade, necrosis, margin width, number of excisions, DCIS size, estrogen receptor, progesterone receptor, radiation therapy, and endocrine therapy) and six mammography and ultrasound variables (breast density, detection modality, mammography and ultrasound patterns, morphology and distribution of calcifications) were analyzed. A nomogram for predicting 10-year IBTR probabilities was constructed using the variables associated with IBTR identified from the Cox proportional hazard regression analysis in the development cohort. The performance of the developed nomogram was evaluated in the external validation cohort using a calibration plot and 10-year area under the receiver operating characteristic curve (AUROC) and compared with the Memorial Sloan-Kettering Cancer Center (MSKCC) nomogram., Results: The development cohort included 702 women (median age [interquartile range], 50 [44-56] years), of whom 30 (4%) women experienced IBTR. The validation cohort included 182 women (48 [43-54] years), 18 (10%) of whom developed IBTR. A nomogram was constructed using three clinical-pathologic variables (age, margin, and use of adjuvant radiation therapy) and two mammographic variables (breast density and calcification morphology). The nomogram was appropriately calibrated and demonstrated a comparable 10-year AUROC to the MSKCC nomogram (0.73 vs. 0.66, P = 0.534) in the validation cohort., Conclusion: Our nomogram provided individualized risk estimates for women with DCIS treated with BCS, demonstrating a discriminative ability comparable to that of the MSKCC nomogram., Competing Interests: The authors have no potential conflicts of interest to disclose., (Copyright © 2024 The Korean Society of Radiology.)

Background: This study aimed to explore the clinical utility of targeted MECP2 testing in a large cohort of females with neurodevelopmental delays. Our aim was to identify suitable candidates for testing based on prevailing diagnostic criteria., Methods: Eligible participants with global developmental delay/arrest or regression before age 36 months underwent MECP2 testing. MECP2-positive patients were further categorized based on Rett syndrome (RTT) diagnostic criteria, including typical, atypical, possible, and unclassified, to assess disease typicality and progression with respect to age., Results: Of the 683 patients, 162 (23.7%) were diagnosed with MECP2-related RTT. Global developmental delay was the predominant initial symptom in approximately 75% of the cohort with developmental arrest/regression at testing. Symptoms emerged before age six months in 14 patients (8.6%). The average age at the time of MECP2 testing was 3.7 years, with 31.5% of the patients tested under two years. Of those under two years, 15 were initially categorized into the unclassified group; however, 12 were later reclassified into the typical/atypical RTT groups based on follow-up evaluation. Among the 119 patients monitored beyond age five years, 80% displayed typical RTT symptoms, 10 remained unclassified, and 9.8% had exonic deletions, posing challenges for detection using next-generation sequencing., Conclusions: Targeted MECP2 testing has emerged as a clinically valuable tool with a high diagnostic yield, including the identification of small deletions. Given that younger patients may not always meet the classic RTT criteria, this study recommends targeted MECP2 testing in younger patients without typical RTT features., Competing Interests: Declaration of competing interest The authors declare that there are no competing interests related to the writing of this manuscript., (Copyright © 2024. Published by Elsevier Inc.)

Magnetic resonance imaging (MRI) can extract the tissue conductivity values from in vivo data using the so-called phase-based magnetic resonance electrical properties tomography (MR-EPT). However, this procedure suffers from noise amplification caused by the use of the Laplacian operator. To counter this issue, we propose a novel preprocessing denoiser for magnetic resonance transceive phase images, operating in an unsupervised manner. Inspired by the deep image prior approach, we apply the random initialization of a convolutional neural network, which enforces an implicit regularization. Additionally, we introduce Stein's unbiased risk estimator, which is the unbiased estimator of the mean square error for optimizing the network without the need for label images. This modification not only tackles the overfitting problem inherent in the deep image prior approach but also operates within a purely unsupervised framework. In addition, instead of using phase images, we use real and imaginary images, which aligns with the theoretical model of the risk estimator. Our generative model needs neither the preparation of training datasets nor prior training procedure, and it maintains adaptability across various resolutions and signal-to-noise ratio levels. In testing. our method significantly diminished residual error remaining in phase maps, quantitatively as well as qualitatively, for both phantom and simulated brain data. Furthermore, it outperformed other denoising methods in reducing noise amplification and boundary error. When applied to healthy volunteer and patient data, the proposed method revealed reduced error in the reconstructed conductivity maps, with conductivity values aligning well with established literature values. To the best of our knowledge, this is the first blind approach using a purely unsupervised denoising framework that can implement a 2D phase-based MR-EPT reconstruction algorithm. The source code is available at https://github.com/Yonsei-MILab/Implicit-Regularization-forMREPT-with-SURE.

Fever of unknown origin (FUO) remains a formidable diagnostic challenge in the field of medicine. Numerous studies suggest an association between FUO and genetic factors, including chromosomal abnormalities. Here, we report a female patient with a 4.5 Mb Xp microdeletion, who presented with recurrent FUO, bacteremia, colitis, and hematochezia. To elucidate the underlying pathogenic mechanism, we employed a comprehensive approach involving single cell RNA sequencing, T cell receptor sequencing, and flow cytometry to evaluate CD4 T cells. Analysis of peripheral blood mononuclear cells revealed augmented Th1, Th2, and Th17 cell populations, and elevated levels of proinflammatory cytokines in serum. Notably, the patient exhibited impaired Treg cell function, possibly related to deletion of genes encoding FOPX3 and WAS. Single cell analysis revealed specific expansion of cytotoxic CD4 T lymphocytes, characterized by upregulation of various signature genes associated with cytotoxicity. Moreover, interferon-stimulated genes were upregulated in the CD4 T effector memory cluster. Further genetic analysis confirmed maternal inheritance of the Xp microdeletion. The patient and her mother exhibited X chromosome-skewed inactivation, a potential protective mechanism against extensive X chromosome deletions; however, the mother exhibited complete skewing and the patient exhibited incomplete skewing (85:15), which may have contributed to emergence of immunological symptoms. In summary, this case report describes an exceptional instance of FUO stemming from an incompletely inactivated X chromosome microdeletion, thereby increasing our understanding of the genetics underpinning FUO., (© 2024. The Author(s).)

Calcium pyrophosphate deposition disease is categorized into radiographic chondrocalcinosis, acute calcium pyrophosphate arthritis, chronic calcium pyrophosphate arthritis, and osteoarthritis with calcium pyrophosphate deposition. These entities collectively are characterized by the deposition of calcium into joints, which then may cause localized and systemic inflammation, resulting in pain and swelling in the affected joints. Patients with the ANKH gene are more susceptible to the development of CPP arthritis as are those with primary hyperparathyroidism, hypomagnesemia, and hemochromatosis. Radiographic chondrocalcinosis is asymptomatic. Acute calcium pyrophosphate arthritis results in self-limited periods of joint pain and swelling in the affected joint. Along with localized inflammation, there may also be systemic inflammation characterized by fever and elevated inflammatory markers. Chronic calcium pyrophosphate arthritis results in periods of quiescence interrupted by flares that are identical to acute periods of disease. Osteoarthritis associated calcium pyrophosphate arthritis presents with chronic pain well described in osteoarthritis with periods of acute flares. In 2023, a joint effort by the American College of Rheumatology and the European League Against Rheumatism developed guidelines meant to aid in the recognition of calcium pyrophosphate deposition diseases. The diagnosis is made if there is proof of either crowned dens syndrome or synovial fluid analysis demonstrating calcium pyrophosphate crystals or when more than 56 points are summed utilizing the criteria described in the guidelines. Radiographic chondrocalcinosis requires no therapy. Acute calcium pyrophosphate arthritis is treated with the goal of aborting the flare. Treatment options include nonsteroidal anti-inflammatory drugs (NSAIDs), colchicine, oral corticosteroids, parenteral corticosteroids, intraarticular corticosteroids, IL-1 inhibitors, or parenteral adrenocorticotropic hormone (ACTH). The goal in treatment for chronic calcium pyrophosphate arthritis is the suppression of acute flares. The drugs used for acute flare treatment may be given as maintenance therapy with the additional options of methotrexate and hydroxychloroquine., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Kim et al.)

Background: In children suspected of asthma, diagnosis is confirmed via variable expiratory airflow limitation. However, there is no single gold standard test for diagnosing asthma., Objective: This study aimed to evaluate the pulmonary function characteristics in children suspected of asthma without bronchodilator response (BDR) and bronchial hyperresponsiveness (BHR)., Methods: We utilized two separate real-world retrospective observational cohorts of children who underwent both spirometry and bronchial provocation testing for asthma. Spirometry parameters were collected and compared between definite asthma, probable asthma, and non-asthma groups. The original cohort comprised 1199 children who visited the Severance Hospital (Seoul, Korea) between January 2017 and December 2019. The external cohort included 105 children who visited the Gangnam Severance Hospital between January 2019 and December 2019., Results: Probable asthma accounted for 16.8% and 32.4% of the original and external cohorts, respectively. This group showed a significantly higher FeNO level and prevalence of allergic sensitization. Baseline forced expiratory volume in 1 second (FEV1), FEV1/forced vital capacity (FVC), forced expiratory flow at 25-75% of FVC (FEF25-75), and FEF75 showed stepwise decrements from non-asthma, probable asthma, to definite asthma patients (P < 0.001). The probable asthma group showed significantly higher odds of abnormal FEV1/FVC (OR, 2.24 [95%CI, 1.43-3.52])and FEF25-75 (2.05 [1.13-3.73]) than the non-asthma group and lower odds of abnormal FEV1(0.05 [0.01-0.19]),FEV1 /FVC (0.27 [0.18-0.41]), FEF25-75 (0.17 [0.11-0.28]), and FEF75 (0.14 [0.08-0.24]) compared to the definite asthma group. The external cohort was consistent with the original cohort., Conclusion: We show evidence of airway dysfunction in children for whom a high clinical suspicion of asthma exists without evidence of BDR and BHR. Repeated pulmonary function tests that closely monitor for subtle lung function impairments and active utilization of additional tests, such as allergic screening and FeNO, should be considered to close the gap in diagnosing asthma.

Objective: This study aimed to develop and validate a comprehensive self-report questionnaire to assess emotional and behavioral problems and psychological trauma in maltreated children., Methods: The Mental Health Scale for Maltreated Children (MHS-MC) was constructed to encompass five major symptoms (depression, anxiety, inattention/hyperactivity/impulsivity, aggression/defiance, and psychological trauma) prevalent in maltreated children. Critical items and ego-resilience subscale were also devised to increase clinical utility. After informed consent, 205 children (maltreated children, n=157, 76.6%) were recruited nationwide, and they answered a package of self-report measures, including the MHS-MC. Reliability, construct validity, concurrent validity, and criterion-related validity were examined to explore the psychometric properties., Results: The reliability was good to excellent. Confirmatory factor analysis yielded a five-factorial solution for the symptom subscales supporting construct validity. In logistic regression, the total scores of the MHS-MC predicted membership in the maltreated group. Criterion-related validity was generally satisfactory in that all subscales of the MHS-MC showed significant correlations with relevant measures in the expected direction., Conclusion: This is the first attempt to develop a comprehensive psychological scale based on nationwide data collected from maltreated Korean children. We hope that the continued standardization of this scale will contribute to evidence-based clinical and policy decisionmaking for maltreated children.

Purpose: Despite the risk of anaphylaxis, oral food challenges (OFCs) are performed clinically for various indications, particularly to confirm tolerance development. This study aimed to assess OFCs by relevant indications and build an outcome prediction model to help determine when to perform OFCs in children who are likely to have developed immune tolerance., Methods: In total, 432 pediatric OFCs were retrospectively analyzed according to indications. Clinical characteristics, serum total immunoglobulin (Ig) E, blood eosinophils, and specific IgE and IgG4 levels for food allergens were noted and compared. Machine learning was utilized to select the most important variables in determining the passage of the OFCs, and prediction models were constructed using the selected variables., Results: OFCs were most commonly performed to confirm tolerance development (number, %; 267, 61.8%). The most common food allergens tested were egg (191, 44.2%) and milk (135, 31.3%). Children who passed the egg challenges for confirming tolerance acquisition had significantly lower egg white-specific IgE level ( P = 0.008). Similarly, those who passed milk challenges had significantly lower cow's milk-specific IgE ( P = 0.002) and casein-specific IgE levels ( P = 0.005). We developed a nomogram to predict the outcome of OFCs to determine the tolerance acquisition with the selected variables; lower food-specific IgE, higher total IgE, and younger age indicated a higher probability of passage. The area under the curve (95% confidence interval) was 0.623 (0.503-0.743) for egg and 0.734 (0.628-0.840) for milk., Conclusions: Serum total IgE and food-specific IgE combined with age showed trends toward passing OFCs for confirming tolerance development. The constructed model may be used by clinicians as a practical guide for minimizing the risks of OFCs and a timely reintroduction for children with food allergies., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2024 The Korean Academy of Asthma, Allergy and Clinical Immunology • The Korean Academy of Pediatric Allergy and Respiratory Disease.)

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 vacuum-assisted 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., Trial Registration: ClinicalTrials.gov Identifier: NCT05505357. Registered on August 17, 2022. Clinical Research Information Service Identifier: KCT0007638. Registered on July 25, 2022., Competing Interests: Jiwon Koh reported receiving consultation fees from DCGen. Co., Ltd., outside the submitted work. Hee-Chul Shin, Wonshik Han, and Han-Byoel Lee reported being member of the board of directors of and holding stock and ownership interests at DCGen, Co, Ltd., outside the submitted work. Han-Byoel Lee reported receiving grants in the form of Mammotome® Elite needles from Devicor Medical Products, Inc. for this work. The grant source had no part in the design and preparation of the protocol. No other disclosures were reported., (© 2024 Korean Breast Cancer Society.)

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/mm² 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., Competing Interests: Vivian Youngjean Park and Woo Jung Choi, the editor board member of the Korean Journal of Radiology, were not involved in the editorial evaluation or decision to publish this article. All authors have declared no conflicts of interest., (Copyright © 2023 The Korean Society of Radiology.)