1.Accuracy of Two Direct Antibiotic-Susceptibility Tests and Their Impact on the Optimal Treatment of Enterobacterales-Associated Bloodstream Infection:Comparison of the QMAC-dRAST V2.5 and BD Phoenix M50 Systems
Ji Sang YOON ; Joo An KWON ; Jeong Seob SHIN ; Hyun Soo SEOK ; In Young YOO ; Yeon-Joon PARK
Annals of Laboratory Medicine 2026;46(3):279-288
Background:
Rapid pathogen identification and antibiotic-susceptibility tests (ASTs) are important for treating bloodstream infections. We compared the performance of the QMAC-dRAST and BD Phoenix M50 direct AST (dPhoenix) systems using bacterial pellets prepared from positive blood culture broth and evaluated their impact on treatment modification.
Methods:
Direct AST results for 106 Enterobacterales isolates were retrospectively reviewed. Conventional broth microdilution was used to calculate categorical agreement (CA), very major error (VME), major error (ME), and minor error (mE). For isolates showing high VMEs in both methods, supplementary tests were performed. Clinical impact was evaluated by calculating the time required to obtain AST results (time-to-result) and observing changes in antibiotics prescribed after performing ASTs.
Results:
Both systems showed acceptable overall CA, VME, ME, and mE values (QMACdRAST: 93.6%, 1.6%, 0.9%, and 5.3%, respectively; dPhoenix: 93.1%, 0.9%, 0.6%, and 6.2%, respectively). Piperacillin–tazobactam showed high VMEs with QMAC-dRAST (4/20, 20.0%) and dPhoenix (3/20, 15.0%). Colony AST on 13 isolates revealed that QMACdRAST testing yielded lower minimal inhibitory concentrations (MICs) for piperacillin–tazobactam with three isolates, whereas dPhoenix testing yielded higher MICs with two isolates and lower MICs with two isolates. The average time-to-result was 20.8 hr and 30.1 hr for QMAC-dRAST and dPhoenix, respectively (P < 0.001). After AST, the number of optimal treatments increased from 43 (46.7%) to 72 (78.3%) (P < 0.001).
Conclusions
The QMAC-dRAST and dPhoenix systems provided reliable AST results with a short time-to-result. However, we recommend performing complementary tests, such as the disk diffusion test, for piperacillin–tazobactam.
2.Individualized strategy of treatment for ruptured abdominal aortic aneurysm using causal inference model: a retrospective observational study
Youngki SOHN ; Youngje WOO ; Sangkyun MOK ; Eunju JANG ; Ki-Yoon MOON ; Sun Cheol PARK ; Sang Seob YUN ; Jang Yong KIM
Annals of Surgical Treatment and Research 2026;110(4):259-272
Purpose:
This study was performed to predict individualized treatment strategies in ruptured abdominal aortic aneurysm (rAAA) by estimating the survival benefit of endovascular aneurysm repair (EVAR) and open surgical repair (OSR) based on anatomical and physiological features using a causal inference model.
Methods:
This retrospective study included 45 patients with de novo rAAA who underwent EVAR or OSR between 2012 and 2024. Thirty-three variables were analyzed. The model estimated individualized treatment effects (ITE) for 30-day survival.Model interpretability was assessed using Shapley Additive Explanations (SHAP) analysis. Five-fold cross-validation, receiver operating characteristic (ROC) analysis, and calibration plots were used for model evaluation. A clinical decision tree was developed to derive simplified decision rules.
Results:
The mean ITE was 0.22 ± 0.42, with 33% of patients classified as OSR-benefit candidates. SHAP analysis revealed that suprarenal angle, infrarenal angle, iliac anatomy, and proximal neck characteristics strongly influenced treatment effects. However, some predictors, such as low hemoglobin and systolic blood pressure favoring OSR, conflicted with clinical intuition. ROC analysis showed an area under the curve of 1.00, but calibration suggested overfitting due to a small sample size. Treatment-matched patients had a higher 30-day mortality rate than mismatched patients, suggesting potential bias or unmeasured confounding. The decision tree identified clinically relevant features but displayed structural inconsistencies and impractical cutoff values due to the limited sample size.
Conclusion
The X-learner model demonstrated the feasibility of individualized treatment prediction in rAAA but suffered from overfitting and limited generalizability. Validation with larger multicenter cohorts is necessary to confirm clinical applicability.
3.The Korean Academy of Asthma Allergy and Clinical Immunology guidelines for sublingual immunotherapy
Gwanghui RYU ; Hye Mi JEE ; Hwa Young LEE ; Sung-Yoon KANG ; Kyunghoon KIM ; Ju Hee KIM ; Kyung Hee PARK ; So-Young PARK ; Myong Soon SUNG ; Youngsoo LEE ; Eun-Ae YANG ; Jin-Young MIN ; Eun Kyo HA ; Sang Min LEE ; Yong Won LEE ; Eun Hee CHUNG ; Sun Hee CHOI ; Young-Il KOH ; Seon Tae KIM ; Dong-Ho NAHM ; Jung Won PARK ; Jung Yeon SHIM ; Young Min AN ; Man Yong HAN ; Jeong-Hee CHOI ; Yoo Seob SHIN ; Doo Hee HAN ;
Allergy, Asthma & Respiratory Disease 2024;12(3):125-133
Allergen immunotherapy (AIT) has been used for over a century and has been demonstrated to be effective in treating patients with various allergic diseases. AIT allergens can be administered through various routes, including subcutaneous, sublingual, intralymphatic, oral, or epicutaneous routes. Sublingual immunotherapy (SLIT) has recently gained clinical interest, and it is considered an alternative treatment for allergic rhinitis (AR) and asthma. This review provides an overview of the current evidence-based studies that address the use of SLIT for treating AR, including (1) mechanisms of action, (2) appropriate patient selection for SLIT, (3) the current available SLIT products in Korea, and (4) updated information on its efficacy and safety. Finally, this guideline aims to provide the clinician with practical considerations for SLIT.
4.The Korean Academy of Asthma Allergy and Clinical Immunology guidelines for allergen immunotherapy
Hwa Young LEE ; Sung-Yoon KANG ; Kyunghoon KIM ; Ju Hee KIM ; Gwanghui RYU ; Jin-Young MIN ; Kyung Hee PARK ; So-Young PARK ; Myongsoon SUNG ; Youngsoo LEE ; Eun-Ae YANG ; Hye Mi JEE ; Eun Kyo HA ; Yoo Seob SHIN ; Sang Min LEE ; Eun Hee CHUNG ; Sun Hee CHOI ; Young-Il KOH ; Seon Tae KIM ; Dong-Ho NAHM ; Jung Won PARK ; Jung Yeon SHIM ; Young Min AN ; Doo Hee HAN ; Man Yong HAN ; Yong Won LEE ; Jeong-Hee CHOI ;
Allergy, Asthma & Respiratory Disease 2024;12(3):102-124
Allergen immunotherapy (AIT) is a causative treatment of allergic diseases in which allergen extracts are regularly administered in a gradually escalated doses, leading to immune tolerance and consequent alleviation of allergic diseases. The need for uniform practice guidelines in AIT is continuously growing as the number of potential candidates for AIT increases and new therapeutic approaches are tried. This updated version of the Korean Academy of Asthma Allergy and Clinical Immunology recommendations for AIT, published in 2010, proposes an expert opinion by specialists in allergy, pediatrics, and otorhinolaryngology. This guideline deals with the basic knowledge of AIT, including mechanisms, clinical efficacy, allergen standardization, important allergens in Korea, and special consideration in pediatrics. The article also covers the methodological aspects of AIT, including patient selection, allergen selection, schedule and doses, follow-up care, efficacy measurements, and management of adverse reactions. Although this guideline suggests the optimal dosing schedule, an individualized approach and modifications are recommended considering the situation for each patient and clinic.
5.Contribution of Enhanced Locoregional Control to Improved Overall Survival with Consolidative Durvalumab after Concurrent Chemoradiotherapy in Locally Advanced Non–Small Cell Lung Cancer: Insights from Real-World Data
Jeong Yun JANG ; Si Yeol SONG ; Young Seob SHIN ; Ha Un KIM ; Eun Kyung CHOI ; Sang-We KIM ; Jae Cheol LEE ; Dae Ho LEE ; Chang-Min CHOI ; Shinkyo YOON ; Su Ssan KIM
Cancer Research and Treatment 2024;56(3):785-794
Purpose:
This study aimed to assess the real-world clinical outcomes of consolidative durvalumab in patients with unresectable locally advanced non–small cell lung cancer (LA-NSCLC) and to explore the role of radiotherapy in the era of immunotherapy.
Materials and Methods:
This retrospective study assessed 171 patients with unresectable LA-NSCLC who underwent concurrent chemoradiotherapy (CCRT) with or without consolidative durvalumab at Asan Medical Center between May 2018 and May 2021. Primary outcomes included freedom from locoregional failure (FFLRF), distant metastasis-free survival (DMFS), progression-free survival (PFS), and overall survival (OS).
Results:
Durvalumab following CCRT demonstrated a prolonged median PFS of 20.9 months (p=0.048) and a 3-year FFLRF rate of 57.3% (p=0.008), compared to 13.7 months and 38.8%, respectively, with CCRT alone. Furthermore, the incidence of in-field recurrence was significantly greater in the CCRT-alone group compared to the durvalumab group (26.8% vs. 12.4%, p=0.027). While median OS was not reached with durvalumab, it was 35.4 months in patients receiving CCRT alone (p=0.010). Patients positive for programmed cell death ligand 1 (PD-L1) expression showed notably better outcomes, including FFLRF, DMFS, PFS, and OS. Adherence to PACIFIC trial eligibility criteria identified 100 patients (58.5%) as ineligible. The use of durvalumab demonstrated better survival regardless of eligibility criteria.
Conclusion
The use of durvalumab consolidation following CCRT significantly enhanced locoregional control and OS in patients with unresectable LA-NSCLC, especially in those with PD-L1–positive tumors, thereby validating the role of durvalumab in standard care.
6.Dental Age Estimation Using the Demirjian Method: Statistical Analysis Using Neural Networks
Byung-Yoon ROH ; Jong-Seok LEE ; Sang-Beom LIM ; Hye-Won RYU ; Su-Jeong JEON ; Ju-Heon LEE ; Yo-Seob SEO ; Ji-Won RYU ; Jong-Mo AHN
Korean Journal of Legal Medicine 2023;47(1):1-7
In children and adolescents, dental age estimation is performed with the development of the teeth. Various statistical analysis methods have been used to determine the relationship between age and dental maturity and develop an accurate method of age calculation. This study attempted to apply a neural network model for the statistical analysis of dental age estimation in children and evaluated its applicability. This study used 1196 panoramic radiographs of patients aged 3–16 years, and 996 and 200 were randomly classified into training and test sets, respectively. The dental maturity of the mandibular left teeth was evaluated using Demirjian's method, the neural network model using the backpropagation algorithm was derived using training sets, and the errors were evaluated using 100 radiographs of each male and female as test sets. In addition, multiple linear regression analysis was conducted on the same training set, and the error was calculated by applying it to the test set and comparing it with the error of the neural network model. In the neural network model, the mean absolute error (MAE) and root mean squared error (RMSE) were 0.589 and 0.783 in male subjects and 0.529 and 0.760 in female subjects, respectively. In the multiple linear regression model, the MAE and RMSE were 0.600 and 0.748 in male subjects and 0.566 and 0.789 in female subjects, respectively. When applying the neural network model to the statistical analysis of the dental developmental stage, the results were as accurate as those of conventional statistical analysis methods. This study’s approach is expected to be useful for estimating the ages of children.
7.Increased Radiosensitivity of Solid Tumors Harboring ATM and BRCA1/2 Mutations
Kyung Hwan KIM ; Han Sang KIM ; Seung-seob KIM ; Hyo Sup SHIM ; Andrew Jihoon YANG ; Jason Joon Bock LEE ; Hong In YOON ; Joong Bae AHN ; Jee Suk CHANG
Cancer Research and Treatment 2022;54(1):54-64
Purpose:
Preclinical data indicate that response to radiotherapy (RT) depends on DNA damage repair. In this study, we investigated the role of mutations in genes related to DNA damage repair in treatment outcome after RT.
Materials and Methods:
Patients with solid tumor who participated in next generation sequencing panel screening using biopsied tumor tissue between October 2013 and February 2019 were reviewed and 97 patients that received RT were included in this study. Best response to RT and the cumulative local recurrence rate (LRR) were compared according to absence or presence of missense, nonsense, and frameshift mutations in ATM and/or BRCA1/2.
Results:
Of the 97 patients, five patients harbored mutation only in ATM, 22 in only BRCA1/2, and six in both ATM and BRCA1/2 (ATMmtBRCAmt). Propensity score matching was performed to select the control group without mutations (ATMwtBRCAwt, n=33). In total, 90 RT-treated target lesions were evaluated in 66 patients. Highest objective response rate of 80% was observed in ATMmtBRCAmt lesions (p=0.007), which was mostly durable. Furthermore, the cumulative 1-year LRR was the lowest in ATMmtBRCAmt lesions and the highest in ATMwtBRCAwt lesions (0% vs. 47.9%, p=0.008). RT-associated toxicities were observed in 10 treatments with no significant difference among the subgroups (p=0.680).
Conclusion
Tumors with ATM and BRCA1/2 mutations exhibited superior tumor response and local control after RT compared to tumors without these mutations. The results are hypothesis generating and suggest the need for integrating the tumor mutation profile of DNA repair genes during treatment planning.
8.Recent Advances in Allergen-Specific Immunotherapy in Humans: A Systematic Review
Sang Pyo LEE ; Yoo Seob SHIN ; Sung-Yoon KANG ; Tae-Bum KIM ; Sang Min LEE
Immune Network 2022;22(1):e12-
Allergen-specific immunotherapy (AIT) is presumed to modulate the natural course of allergic disease by inducing immune tolerance. However, conventional AITs, such as subcutaneous immunotherapy and sublingual immunotherapy, require long treatment durations and often provoke local or systemic hypersensitivity reactions. Therefore, only <5% of allergy patients receive AIT as second-line therapy. Novel administration routes, such as intralymphatic, intradermal and epicutaneous immunotherapies, and synthetic recombinant allergen preparations have been evaluated to overcome these limitations. We will review the updated views of diverse AIT methods, and discuss the limitations and opportunities of the AITs for the treatment of allergic diseases in humans.
9.Monitoring Radiation Doses during Diagnostic and Therapeutic Neurointerventional Procedures: Multicenter Study for Establishment of Reference Levels
Yon-Kwon IHN ; Bum-soo KIM ; Hae Woong JEONG ; Sang Hyun SUH ; Yoo Dong WON ; Young-Jun LEE ; Dong Joon KIM ; Pyong JEON ; Chang-Woo RYU ; Sang-il SUH ; Dae Seob CHOI ; See Sung CHOI ; Sang Heum KIM ; Jun Soo BYUN ; Jieun RHO ; Yunsun SONG ; Woo Sang JEONG ; Noah HONG ; Sung Hyun BAIK ; Jeong Jin PARK ; Soo Mee LIM ; Jung-Jae KIM ; Woong YOON
Neurointervention 2021;16(3):240-251
Purpose:
To assess patient radiation doses during diagnostic and therapeutic neurointerventional procedures from multiple centers and propose dose reference level (RL).
Materials and Methods:
Consecutive neurointerventional procedures, performed in 22 hospitals from December 2020 to June 2021, were retrospectively studied. We collected data from a sample of 429 diagnostic and 731 therapeutic procedures. Parameters including dose-area product (DAP), cumulative air kerma (CAK), fluoroscopic time (FT), and total number of image frames (NI) were obtained. RL were calculated as the 3rd quartiles of the distribution.
Results:
Analysis of 1160 procedures from 22 hospitals confirmed the large variability in patient dose for similar procedures. RLs in terms of DAP, CAK, FT, and NI were 101.6 Gy·cm2, 711.3 mGy, 13.3 minutes, and 637 frames for cerebral angiography, 199.9 Gy·cm2, 3,458.7 mGy, 57.3 minutes, and 1,000 frames for aneurysm coiling, 225.1 Gy·cm2, 1,590 mGy, 44.7 minutes, and 800 frames for stroke thrombolysis, 412.3 Gy·cm2, 4,447.8 mGy, 99.3 minutes, and 1,621.3 frames for arteriovenous malformation (AVM) embolization, respectively. For all procedures, the results were comparable to most of those already published. Statistical analysis showed male and presence of procedural complications were significant factors in aneurysmal coiling. Male, number of passages, and procedural combined technique were significant factors in stroke thrombolysis. In AVM embolization, a significantly higher radiation dose was found in the definitive endovascular cure group.
Conclusion
Various RLs introduced in this study promote the optimization of patient doses in diagnostic and therapeutic interventional neuroradiology procedures. Proposed 3rd quartile DAP (Gy·cm2) values were 101.6 for diagnostic cerebral angiography, 199.9 for aneurysm coiling, 225.1 for stroke thrombolysis, and 412.3 for AVM embolization. Continual evolution of practices and technologies requires regular updates of RLs.
10.Development and Validation of a Symptom-Focused Quality of Life Questionnaire (KOQUSS-40) for Gastric Cancer Patients after Gastrectomy
Bang Wool EOM ; Joongyub LEE ; In Seob LEE ; Young-Gil SON ; Keun Won RYU ; Sung Geun KIM ; Hyoung-Il KIM ; Young-Woo KIM ; Seong-Ho KONG ; Oh Kyoung KWON ; Ji-Ho PARK ; Ji Yeong AN ; Chang Hyun KIM ; Byoung-Jo SUH ; Hong Man YOON ; Myoung Won SON ; Ji Yeon PARK ; Jong-Min PARK ; Sang-Ho JEONG ; Moon-Won YOO ; Geum Jong SONG ; Han-Kwang YANG ; Yun-Suhk SUH ; Ki Bum PARK ; Sang-Hoon AHN ; Dong Woo SHIN ; Ye Seob JEE ; Hye-Seong AHN ; Sol LEE ; Jae Seok MIN ; Haejin IN ; Ahyoung KIM ; Hoon HUR ; Hyuk-Joon LEE ;
Cancer Research and Treatment 2021;53(3):763-772
Purpose:
Patients who have undergone gastrectomy have unique symptoms that are not appropriately assessed using currently available tools. This study developed and validated a symptom-focused quality of life (QoL) questionnaire for patients who have received gastrectomy for gastric cancer. Materials and Methods Based on a literature review, patient interviews, and expert consultation by the KOrean QUality of life in Stomach cancer patients Study group (KOQUSS), the initial item pool was developed. Two large-scale developmental studies were then sequentially conducted for exploratory factor analyses for content validity and item reduction. The final item pool was validated in a separate cohort of patients and assessed for internal consistency, test-retest reliability, construct validity, and clinical validity.
Results
The initial questionnaire consisted of 46-items in 12 domains. Data from 465 patients at 11 institutions, followed by 499 patients at 13 institutions, were used to conduct item reduction and exploratory factor analyses. The final questionnaire (KOQUSS-40) comprised 40 items within 11 domains. Validation of KOQUSS-40 was conducted on 413 patients from 12 hospitals. KOQUSS-40 was found to have good model fit. The mean summary score of the KOQUSS-40 was correlated with the EORTC QLQ-C30 and STO22 (correlation coefficients, 0.821 and 0.778, respectively). The KOQUSS-40 score was also correlated with clinical factors, and had acceptable internal consistency (> 0.7). Test-retest reliability was greater than 0.8. Conclusion The KOQUSS-40 can be used to assess QoL of gastric cancer patients after gastrectomy and allows for a robust comparison of surgical techniques in clinical trials.

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