Objective: Little is known about the effects of using different expert-determined reference standards when evaluating the performance of deep learning-based automatic detection (DLAD) models and their added value to radiologists. We assessed the concordance of expert-determined standards with a clinical gold standard (herein, pathological confirmation) and the effects of different expert-determined reference standards on the estimates of radiologists’ diagnostic performance to detect malignant pulmonary nodules on chest radiographs with and without the assistance of a DLAD model. Materials and Methods: This study included chest radiographs from 50 patients with pathologically proven lung cancer and 50 controls. Five expert-determined standards were constructed using the interpretations of 10 experts: individual judgment by the most experienced expert, majority vote, consensus judgments of two and three experts, and a latent class analysis (LCA) model. In separate reader tests, additional 10 radiologists independently interpreted the radiographs and then assisted with the DLAD model. Their diagnostic performance was estimated using the clinical gold standard and various expertdetermined standards as the reference standard, and the results were compared using the t test with Bonferroni correction. Results: The LCA model (sensitivity, 72.6%; specificity, 100%) was most similar to the clinical gold standard. When expertdetermined standards were used, the sensitivities of radiologists and DLAD model alone were overestimated, and their specificities were underestimated (all p-values < 0.05). DLAD assistance diminished the overestimation of sensitivity but exaggerated the underestimation of specificity (all p-values < 0.001). The DLAD model improved sensitivity and specificity to a greater extent when using the clinical gold standard than when using the expert-determined standards (all p-values < 0.001), except for sensitivity with the LCA model (p = 0.094). Conclusion The LCA model was most similar to the clinical gold standard for malignant pulmonary nodule detection on chest radiographs. Expert-determined standards caused bias in measuring the diagnostic performance of the artificial intelligence model.

Percutaneous transthoracic needle biopsy (PTNB) is one of the essential diagnostic procedures for pulmonary lesions. Its role is increasing in the era of CT screening for lung cancer and precision medicine. The Korean Society of Thoracic Radiology developed the first evidence-based clinical guideline for PTNB in Korea by adapting pre-existing guidelines. The guideline provides 39 recommendations for the following four main domains of 12 key questions: the indications for PTNB, pre-procedural evaluation, procedural technique of PTNB and its accuracy, and management of post-biopsy complications. We hope that these recommendations can improve the diagnostic accuracy and safety of PTNB in clinical practice and promote standardization of the procedure nationwide.

OBJECTIVE: We hypothesized that open bronchi within target pulmonary lesions are associated with percutaneous transthoracic needle biopsy (PTNB)-related hemoptysis. We sought to analyze and compare patient characteristics and target features as well as biopsy-related factors between patients with and without PTNB-related hemoptysis. MATERIALS AND METHODS: We retrospectively analyzed 1484 patients (870 males and 614 females; median age, 66 years) who had undergone 1569 cone-beam CT (CBCT)-guided PTNBs. Patient characteristics (sex, age, and pathologic diagnosis), nodule features (nodule type, size, location, and presence of an open bronchus in target nodules), and biopsy-related factors (biopsy needle size, pleura-to-target distance, blood test results, open bronchus unavoidability [OBU] index, etc.) were investigated. OBU index, which was assessed using the pre-procedural CBCT, was a subjective scoring system for the probability of needle penetration into the open bronchus. Univariate analysis and subsequent multivariate logistic regression analysis were conducted to reveal the independent risk factors for PTNB-related hemoptysis. For a subgroup of nodules with open bronchi, a trend analysis between the occurrence of hemoptysis and the OBU index was performed. RESULTS: The independent risk factors for hemoptysis were sex (female; odds ratio [OR], 1.918; p < 0.001), nodule size (OR, 0.837; p < 0.001), open bronchus (OR, 2.101; p < 0.001), and pleura-to-target distance (OR, 1.135; p = 0.003). For the target nodules with open bronchi, a significant trend between hemoptysis and OBU index (p < 0.001) was observed. CONCLUSION: An open bronchus in a biopsy target is an independent predictor of hemoptysis, and careful imaging review may potentially reduce PTNB-related hemoptysis.
Biopsy* ; Biopsy, Needle ; Bronchi* ; Cone-Beam Computed Tomography ; Female ; Hematologic Tests ; Hemoptysis* ; Humans ; Image-Guided Biopsy ; Logistic Models ; Lung Neoplasms ; Male ; Needles ; Odds Ratio ; Retrospective Studies ; Risk Factors*

PURPOSE: The purpose of this study was to investigate the feasibility and survival benefits of combined treatment with radiotherapy and adjuvant temozolomide (TMZ) in a Korean sample. MATERIALS AND METHODS: A total of 750 Korean patients with histologically confirmed glioblastoma multiforme, who received concurrent chemoradiotherapy with TMZ (CCRT) and adjuvant TMZ from January 2006 until June 2011, were analyzed retrospectively. RESULTS: After the first operation, a gross total resection (GTR), subtotal resection (STR), partial resection (PR), biopsy alone were achieved in 388 (51.7%), 159 (21.2%), 96 (12.8%), and 107 (14.3%) patients, respectively. The methylation status of O6-methylguanine-DNA methyltransferase (MGMT) was reviewed retrospectively in 217 patients. The median follow-up period was 16.3 months and the median overall survival (OS) was 17.5 months. The actuarial survival rates at the 1-, 3-, and 5-year OS were 72.1%, 21.0%, and 9.0%, respectively. The median progression-free survival (PFS) was 10.1 months, and the actuarial PFS at 1-, 3-, and 5-year PFS were 42.2%, 13.0%, and 7.8%, respectively. The patients who received GTR showed a significantly longer OS and PFS than those who received STR, PR, or biopsy alone, regardless of the methylation status of the MGMT promoter. Patients with a methylated MGMT promoter also showed a significantly longer OS and PFS than those with an unmethylated MGMT promoter. Patients who received more than six cycles of adjuvant TMZ had a longer OS and PFS than those who received six or fewer cycles. Hematologic toxicity of grade 3 or 4 was observed in 8.4% of patients during the CCRT period and in 10.2% during the adjuvant TMZ period. CONCLUSION: Patients treated with CCRT followed by adjuvant TMZ had more favorable survival rates and tolerable toxicity than those who did not undergo this treatment.
Biopsy ; Chemoradiotherapy* ; Disease-Free Survival ; Follow-Up Studies ; Glioblastoma* ; Humans ; Korea* ; Methylation ; Radiotherapy ; Retrospective Studies* ; Survival Rate

There have been numerous reports on the relationship between eosinophilia and toxocariasis. The present study investigated seropositive rates of toxocariasis among healthy people with or without eosinophilia in urban and rural areas, and assessed risk factors for positive antibody test. A total of 610 healthy people, who visited health check-up (Medicheck(R), Korea Association of Health Promotion), 310 from Seoul and 300 from Gyeongsangnam-do, were subjected for this study. Their serum samples were tested by ELISA with the crude antigen of Toxocara canis larvae. Cross-reactions with other tissue invading helminth antigens were also investigated. Total antibody positive rate of toxocariasis was 8.7% of the 610 subjects. When the subjects were grouped into 3 by their eosinophil counts, the antibody positive rates significantly differed by the groups; 5.9% (18/306) in the group<350/microL, 10.0% (11/110) in the group 350-500/microL, and 12.4% (24/194) in the group>500/microL (P=0.028). A total of 22 serum samples cross-reacted with other tissue-invading helminth antigens. A questionnaire analysis recognized drinking alcohol and smoking as significant risk factors of toxocariasis. In conclusion, toxocariasis antibody positive rate is correlated with eosinophil counts. It is recommended that healthy subjects with eosinophilia by routine health examination and risk factors undergo Toxocara serology by multiantigen ELISA to investigate etiology.
Age Distribution ; Comorbidity ; Eosinophilia/*diagnosis/*epidemiology ; Female ; Humans ; Incidence ; Male ; Middle Aged ; Reference Values ; Republic of Korea/epidemiology ; Risk Factors ; Rural Population/*statistics & numerical data ; Serologic Tests/statistics & numerical data ; Sex Distribution ; Toxocariasis/*diagnosis/*epidemiology ; Urban Population/*statistics & numerical data

OBJECTIVES: Adoption of hospital information systems offers distinctive advantages in healthcare delivery. First, implementation of consolidated hospital information system in Seoul National University Hospital led to significant improvements in quality of healthcare and efficiency of hospital management. METHODS: The hospital information system in Seoul National University Hospital consists of component applications: clinical information systems, clinical research support systems, administrative information systems, management information systems, education support systems, and referral systems that operate to generate utmost performance when delivering healthcare services. RESULTS: Clinical information systems, which consist of such applications as electronic medical records, picture archiving and communication systems, primarily support clinical activities. Clinical research support system provides valuable resources supporting various aspects of clinical activities, ranging from management of clinical laboratory tests to establishing care-giving procedures. CONCLUSIONS: Seoul National University Hospital strives to move its hospital information system to a whole new level, which enables customized healthcare service and fulfills individual requirements. The current information strategy is being formulated as an initial step of development, promoting the establishment of next-generation hospital information system.
Adoption ; Confidentiality ; Delivery of Health Care ; Electronic Health Records ; Hospital Information Systems ; Information Systems ; Management Information Systems ; Quality of Health Care ; Radiology Information Systems ; Referral and Consultation

Lymphomas of mucosa-associated lymphoid tissue (MALT) comprise 7% of all newly diagnosed non-Hodgkin's lymphomas. Helicobacter pylori (H. pylori) negative gastric MALT lymphomas account for 28 to 45% of gastric MALT lymphomas. H. pylori infection has a close relationship with most gastric low-grade B cell lymphomas of the MALT type. Monoclonal gammopathy can be seen in 36% of the patients and negatively associated with responses to eradication of H. pylori in gastric MALT lymphoma. Here, we describe a case of H. pylori negative MALT lymphoma that arose from the stomach with massive plasmacytic differentiation mimicking an extramedullary plasmacytoma with monoclonal gammopathy, and that was cured by total gastrectomy, chemotherapy and radiotherapy.
Gastrectomy ; Helicobacter ; Helicobacter pylori ; Humans ; Lymphoid Tissue ; Lymphoma ; Lymphoma, B-Cell ; Lymphoma, B-Cell, Marginal Zone ; Lymphoma, Non-Hodgkin ; Paraproteinemias ; Plasmacytoma ; Stomach

Emergency Medicine is a medical specialty that provides comprehensive emergency care. The spectrum of emergency medicine includes humanity as well as medical care for emergency patients. Since the Korean Society of Emergency Medicine has been established and the training course for emergency residents has begun, quality improvement of the training course still remains to be one of the most important issues in emergency medicine. This report is to understand the current status of training of emergency residents and to improve the quality of training of emergency residents. The survey was performed with questionnaires regarding current status of training and opinions to improve quality of training. The questionnaires were sent to all emergency physicians and emergency residents registered to the Korean Society of Emergency Medicine via an electronic mail or a printed letter. The response rates were 49.6% for emergency physicians and 35.8% for emergency residents. On the basis of the result of this survey, we suggest five proposals for improving the quality of resident training course. These include complete adherence of each institution to training guidelines presented by the Korean Society of Emergency Medicine, development of the education program compatible to each institution, shortening of length of training duration from 4 years to 3 years, promotion of the training environment, and introduction of evaluation examination to the training course.
Education ; Electronic Mail ; Emergencies* ; Emergency Medical Services ; Emergency Medicine ; Humans ; Internship and Residency ; Quality Improvement ; Surveys and Questionnaires

Carcinoid tumors are slow growing, rare neoplasms that arise from enterochromaffin cells, with malignant potential. Primary duodenal carcinoid tumors are rare, the reported incidence being 2.0 ~8.9% of all gastrointestinal carcinoid tumors. Unless the carcinoid syndrome has developed, the non-specificity of the symptoms and physical findings, makes the clinical diagnosis of these tumors difficult. However, with the introduction of large and deep endoscopic biopsies, it is possible to diagnose duodenal carcinoid tumors at an early stage. Usually, local resection is the therapy of choice because of the very slow growth of the lesion and the low incidence of metastasis. Radical surgery is mandatory only in lesions more than 2 cm in diameter, or in the presence of muscular invasion. A 69-year-old female visited our medical department, having had symptoms of upper ab-dominal pain and intermittent melena for 1 week. Endoscopic examination showed 2.5 2.5 cm sized elevated mass lesion with central ulceration in the anterior wall side of the duodenal bulb. Immunohistochemical stains of the biopsy specimen showed that the tumor cells are positive reactivity for NSE (neuron-specific-enolase), chromogranin A, and cyto-keratin.
Aged ; Biopsy ; Carcinoid Tumor* ; Chromogranin A ; Coloring Agents ; Diagnosis ; Duodenum ; Enterochromaffin Cells ; Female ; Humans ; Incidence ; Melena ; Neoplasm Metastasis ; Ulcer