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Simple Summary: The 18F-FDG PET parameters reflecting the intensity and distribution of glucose uptake by the tumor are associated with prognosis in non-small-cell lung cancer (NSCLC) patients. We developed and evaluated an imaging-based model utilizing these 18F-FDG PET-derived features for predicting the five-year survival in NSCLC patients after curative surgery. The PET-based risk score constructed using the LASSO logistic method outperformed the predictive performances of individual 18F-FDG PET parameters. The PET-based risk score was an independent prognostic factor for clinical variables. Additionally, it demonstrated better predictive performance when combined with clinical variables. The FDG PET-based imaging model could aid in risk stratification for personalized adjuvant treatment and follow-up management of NSCLC patients after surgery. The aim of our retrospective study is to develop and assess an imaging-based model utilizing 18F-FDG PET parameters for predicting the five-year survival in non-small-cell lung cancer (NSCLC) patients after curative surgery. A total of 361 NSCLC patients who underwent curative surgery were assigned to the training set (n = 253) and the test set (n = 108). The LASSO regression model was used to construct a PET-based risk score for predicting five-year survival. A hybrid model that combined the PET-based risk score and clinical variables was developed using multivariate logistic regression analysis. The predictive performance was determined by the area under the curve (AUC). The individual features with the best predictive performances were co-occurrence_contrast (AUC = 0.675) and SUL peak (AUC = 0.671). The PET-based risk score was identified as an independent predictor after adjusting for clinical variables (OR 5.231, 95% CI 1.987–6.932; p = 0.009). The hybrid model, which integrated clinical variables, significantly outperformed the PET-based risk score alone in predictive accuracy (AUC = 0.771 vs. 0.696, p = 0.022), a finding that was consistent in the test set. The PET-based risk score, especially when integrated with clinical variables, demonstrates good predictive ability for five-year survival in NSCLC patients following curative surgery. [ABSTRACT FROM AUTHOR]

Backgrounds: Limited data are available on racial differences in the clinical features of chronic bronchitis (CB) patients with chronic obstructive pulmonary disease (COPD). In this study, we aimed to compare clinical features among CB patients of different races. We also analyzed the clinical significance of CB, defined classically and based on the COPD Assessment Test (CAT), to validate the CAT-based definition. Methods: We analyzed patient data extracted from the Korean COPD Subgroup Study (KOCOSS) cohort (2012–2021) and US Genetic Epidemiology of COPD (COPDGene) study (2008–2011). We compared clinical characteristics among CB and non-CB patients of three different races using two CB definitions. Results: In this study, 3,462 patients were non-Hispanic white (NHW), 1,018 were African American (AA), and 1,793 were Asian. The proportions of NHW, AA, and Asian patients with CB according to the classic definition were 27.4%, 20.9%, and 10.7%, compared with 25.2%, 30.9%, and 23.0% according to the CAT-based definition, respectively. The risk of CB prevalence was highest in NHW and lowest in Asian COPD patients. Among all races, CB patients were more likely to be current smokers, have worse respiratory symptoms and poorer health-related quality of life (HrQoL), and to have decreased lung function and exercise capacity. Most of these characteristics showed similar associations with the outcomes between the two definitions of CB. A binominal regression model revealed that CB patients of all races had an increased risk of future exacerbations according to both CB definitions, except for Asian patients with classically defined CB. Conclusions: The presence of CB was associated with worse respiratory symptoms, HrQoL, exercise capacity and lung function, and more exacerbations, regardless of race or CB definition. The CAT-based definition may be more useful for assessing the risk of future exacerbations in Asian COPD patients. [ABSTRACT FROM AUTHOR]

Patient-derived organoids (PDOs) are valuable in predicting response to cancer therapy. PDOs are ideal models for precision oncologists. However, their practical application in guiding timely clinical decisions remains challenging. This study focused on patients with advanced EGFR-mutated non-small cell lung cancer and employed a cancer organoid-based diagnosis reactivity prediction (CODRP)-based precision oncology platform to assess the efficacy of EGFR inhibitor treatments. CODRP was employed to evaluate EGFR-tyrosine kinase inhibitors (TKI) drug sensitivity. The results were compared to those obtained using area under the curve index. This study validated this index by testing lung cancer-derived organoids in 14 patients with lung cancer. The CODRP index-based drug sensitivity test reliably classified patient responses to EGFR-TKI treatment within a clinically suitable 10-day timeline, which aligned with clinical drug treatment responses. This approach is promising for predicting and analyzing the efficacy of anticancer, ultimately contributing to the development of a precision medicine platform. [ABSTRACT FROM AUTHOR]

Simple Summary: This research investigates the effects of South Korea's national insurance coverage (NIC) expansion and the inclusion of genetic counselors on BRCA1/2 mutation testing rates in breast cancer patients. By analyzing data from the Samsung Medical Center, the study reveals a notable increase in testing rates following NIC expansion and the addition of genetic counselors. Particularly noteworthy is the rise in testing rates among triple-negative breast cancer (TNBC) patients under 60. Additionally, the involvement of genetic counselors led to a significant increase in follow-up patients undergoing testing. The NIC expansion also broadened insurance coverage for TNBC patients, thereby enhancing testing accessibility. These findings underscore the positive impact of NIC expansion and genetic counselor involvement on improving patient management. Addressing financial barriers to testing and integrating genetic counseling into healthcare practices present promising strategies for advancing early detection and tailored treatment approaches, thereby contributing to global efforts in cancer care and management. Purpose: This study aims to evaluate the impact of South Korea's national insurance coverage (NIC) expansion and the addition of genetic counselors on BRCA1/2 mutation testing rates in breast cancer patients. Materials and Methods: A retrospective review was conducted at the Samsung Medical Center (SMC), dividing patients into three groups: pre-NIC expansion, post-NIC expansion, and post-extra genetic counselor involvement. The number of BRCA1/2 tests performed and the detection rates among newly diagnosed and follow-up patients, particularly focusing on triple-negative breast cancer (TNBC) cases, were analyzed. Results: Post-NIC expansion, there was a significant increase in BRCA1/2 testing rates, with a gradual rise in detection rates while maintaining statistical significance. TNBC patients under 60 experienced substantial increases in testing rates. The number of follow-up patients recalled for testing also rose significantly after the extra genetic counselor involvement. Additionally, NIC expansion increased insurance coverage for TNBC patients, enhancing accessibility to testing. Conclusion: The study highlights the positive impact of NIC expansion and genetic counselor involvement on BRCA1/2 mutation testing rates and subsequent patient management. Addressing financial barriers to testing and incorporating genetic counseling significantly improve patient outcomes. This model provides a potential strategy for enhancing early detection and personalized treatment for breast cancer patients with BRCA1/2 mutations, contributing to global cancer management efforts. [ABSTRACT FROM AUTHOR]

Purpose Programmed death-1/programmed death-ligand 1 (PD-L1) inhibitors have shown efficacy in metastatic esophageal squamous cell carcinoma (ESCC) therapy. However, data is still limited regarding neoadjuvant immunotherapy for operable ESCC. Materials and Methods Patients with clinical stage T2 or T3 and N0 ESCC received three cycles of nivolumab therapy every two weeks before surgical resection. The primary endpoint is major pathologic responses (MPR) rate (= 10% of residual viable tumor [RVT]). Results Total 20 patients completed the planned nivolumab therapy. Among them, 17 patients underwent surgery as protocol, showing MPR in two patients (MPR rate, 11.8%), including one pathologic complete response, on conventional pathologic response evaluation. Pathologic response was re-evaluated using the immune-related pathologic response criteria based on immune-related RVT (irRVT). Three patients were classified as immunologic major pathologic response (iMPR; = 10% irRVT, iMPR rate: 17.6%), five as pathologic partial response (> 10% and < 90% irRVT), and nine as pathologic nonresponse (= 90% irRVT). The combined positive score (CPS) for PD-L1 in the baseline samples was predictable for iMPR, with the probability as 37.5% in CPS = 10 (3/8) and 0% in CPS < 10 (0/9). Conclusion Although the efficacy of neoadjuvant nivolumab therapy was modest in unselected ESCC patients, further researches on neoadjuvant immunotherapy are necessary in patients with PD-L1 expressed ESCC. [ABSTRACT FROM AUTHOR]

There have been previous studies conducted to predict postoperative lung function with pulmonary function tests (PFTs). Computing tomography (CT) can quantitatively measure small airway walls' thickness, lung volume, pulmonary vessel volume, and emphysema area, which reflect the severity of respiratory diseases. These measurements are considered imaging biomarkers. This study aimed to predict postoperative lung function with imaging biomarkers. A retrospective analysis of 79 patients with lung cancer who had undergone lung surgery was completed. Postoperative lung function measured by forced expiratory volume in one second (FEV1) was defined as an outcome. Preoperative clinico-pathological parameters and imaging biomarkers representing airway walls' thickness, severity of emphysema, total lung volume, and pulmonary vessel volume were measured quantitatively in chest CT by an automated segmentation software, AVIEW COPD. Pi1 was defined as the first percentile along the histogram of lung attenuation that represents the degree of emphysema. Wafw was defined as the airway thickness, which was calculated by the full-width at half-maximum method. Logistic and linear regressions were used to assess these variables. If the actual postoperative FEV1 was higher than the postoperative FEV1 projected by a formula, the group was considered to be preserved. Among the 79 patients, 16 of the patients were grouped as a non-preserved group, and 63 of them were grouped as a preserved group. The patients in the preserved FEV1 group had a higher vessel volume than the non-preserved group. Pi1 and Wafw were independent predictors of postoperative lung function. Imaging biomarkers can be considered significant variables in predicting postoperative lung function in patients with lung cancer. [ABSTRACT FROM AUTHOR]

In this study, we propose an implementation method of the Encoder Data (EnDat) interface master for slave encoders using only a configurable logic block (CLB) and a serial peripheral interface (SPI) integrated into microcontroller units. By programming the CLB device to execute logic functions and finite state machines designed for the EnDat interface master operation, we realize the EnDat and SPI clocks that are required for the EnDat interface master operation. This approach is cost-efficient because additional hardware components, such as a field-programmable gate array or a complex programmable logic device, are unnecessary for the master implementation. We build a one-axis feed drive system that is powered by an AC motor and equipped with an EnDat linear encoder for measuring table speed and position. By performing various experiments for table position and speed control based on the built feed drive system, we verify the performance and practical usefulness of the implemented EnDat interface master. The maximum EnDat clock frequency without the propagation delay compensation is achieved by 2 MHz, which can cope with 16 kHz control cycle frequency. The usefulness is demonstrated by showing the table speed and position control performance that are acceptable in real applications. [ABSTRACT FROM AUTHOR]

Poor uptake to pulmonary rehabilitation (PR) is still challenging around the world. There have been few nationwide studies investigating whether PR impacts patient outcomes in COPD. We investigated the change of annual PR implementation rate, medical costs, and COPD outcomes including exacerbation rates and mortality between 2015 and 2019. Does PR implementation improve outcomes in patients with COPD in terms of direct cost, exacerbation, and mortality? Data of patients with COPD extracted from a large Korean Health Insurance Review and Assessment service database (2015-2019) were analyzed to determine the trends of annual PR implementation rate and direct medical costs of PR. Comparison of COPD exacerbation rates between pre-PR and post-PR, and the time to first exacerbation and mortality rate according to PR implementation, were also assessed. Among all patients with COPD in South Korea, only 1.43% received PR. However, the annual PR implementation rate gradually increased from 0.03% to 1.4% during 4 years, especially after health insurance coverage commencement. The direct medical cost was significantly higher in the PR group than the non-PR group, but the costs in these groups showed decreasing and increasing trends, respectively. Both the incidence rate and frequency of moderate-to-severe and severe exacerbations were lower during the post-PR period compared with the pre-PR period. The time to the first moderate-to-severe and severe exacerbations was longer in the PR group than the non-PR group. Finally, PR implementation was associated with a significant decrease in mortality. We concluded that health insurance coverage increases PR implementation rates. Moreover, PR contributes toward improving outcomes including reducing exacerbation and mortality in patients with COPD. However, despite the well-established benefits of PR, its implementation rate remains suboptimal. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: The prognostic value of conducting 18F-FDG PET/CT imaging has yielded different results in patients with laryngeal cancer and hypopharyngeal cancer, but these results are controversial, and there is a lack of dedicated studies on each type of cancer. This study aimed to evaluate whether combining radiomic analysis of pre- and post-treatment 18F-FDG PET/CT imaging features and clinical parameters has additional prognostic value in patients with laryngeal cancer and hypopharyngeal cancer. Methods: From 2008 to 2016, data on patients diagnosed with cancer of the larynx and hypopharynx were retrospectively collected. The patients underwent pre- and post-treatment 18F-FDG PET/CT imaging. The values of ΔPre-Post PET were measured from the texture features. Least absolute shrinkage and selection operator (LASSO) Cox regression was used to select the most predictive features to formulate a Rad-score for both progression-free survival (PFS) and overall survival (OS). Kaplan–Meier curve analysis and Cox regression were employed to assess PFS and OS. Then, the concordance index (C-index) and calibration plot were used to evaluate the performance of the radiomics nomogram. Results: Study data were collected for a total of 91 patients. The mean follow-up period was 71.5 mo. (8.4–147.3). The Rad-score was formulated based on the texture parameters and was significantly associated with both PFS (p = 0.024) and OS (p = 0.009). When predicting PFS, only the Rad-score demonstrated a significant association (HR 2.1509, 95% CI [1.100–4.207], p = 0.025). On the other hand, age (HR 1.116, 95% CI [1.041–1.197], p = 0.002) and Rad-score (HR 33.885, 95% CI [2.891–397.175], p = 0.005) exhibited associations with OS. The Rad-score value showed good discrimination when it was combined with clinical parameters in both PFS (C-index 0.802–0.889) and OS (C-index 0.860–0.958). The calibration plots also showed a good agreement between the observed and predicted survival probabilities. Conclusions: Combining clinical parameters with radiomics analysis of pre- and post-treatment 18F-FDG PET/CT parameters in patients with laryngeal cancer and hypopharyngeal cancer might have additional prognostic value. [ABSTRACT FROM AUTHOR]

Background: Comorbidities of chronic obstructive pulmonary disease (COPD) influence clinical characteristics and prognosis. Objectives: This study compared the clinical characteristics and exacerbation rate of COPD according to the presence of depression or anxiety. Design: This study used data from The Korea COPD Subgroup Study (KOCOSS) cohort, a nationwide prospective cohort from 54 medical centers, between April 2012 and 2019. Methods: Depression and anxiety were diagnosed with the Beck Depression Inventory and Beck Anxiety Inventory. Negative binomial regression analysis was performed to analyze the frequency of exacerbations in depressed patients and anxiety. Differences in lung function trajectory according to presence of depression/anxiety were analyzed using a linear mixed model. Results: In all, 2147 patients were enrolled. Depressed patients or anxiety had lower lung function, higher modified Medical Research Council (mMRC) grade, St. George Respiratory Questionnaire (SGRQ) score, and COPD assessment test score, and higher rates of exacerbation in the past year than those without depression/anxiety. Depressed patients had a higher frequency of moderate to severe exacerbations [Incidence Rate Ratio (IRR): 1.57, CI: 1.17–2.11, p = 0.002] and those with anxiety had higher frequencies of moderate to severe (IRR: 1.52, CI: 1.03–2.27, p = 0.038) and severe exacerbations (IRR: 2.13, CI: 1.09–4.15, p = 0.025) during 1-year follow-up compared to those without these comorbidities. The differences in the change in annual forced expiratory volume in 1 seconds (FEV1) over 3 years according to the presence of depression or anxiety were not statistically significant. Conclusion: Depressed and anxious patients showed increased respiratory symptoms and exacerbation rate as well as reduced health-related quality of life, whereas there were no significant differences in changes in lung function between groups with and without depression/anxiety. [ABSTRACT FROM AUTHOR]

Background: Recently, cancer organoid-based drug sensitivity tests have been studied to predict patient responses to anticancer drugs. The area under curve (AUC) or IC50 value of the dose-response curve (DRC) is used to differentiate between sensitive and resistant patient's groups. This study proposes a multi-parameter analysis method (cancer organoid-based diagnosis reactivity prediction, CODRP) that considers the cancer stage and cancer cell growth rate, which represent the severity of cancer patients, in the sensitivity test. Methods: On the CODRP platform, patient-derived organoids (PDOs) that recapitulate patients with lung cancer were implemented by applying a mechanical dissociation method capable of high yields and proliferation rates. A disposable nozzle-type cell spotter with efficient high-throughput screening (HTS) has also been developed to dispense a very small number of cells due to limited patient cells. A drug sensitivity test was performed using PDO from the patient tissue and the primary cancer characteristics of PDOs were confirmed by pathological comparision with tissue slides. Results: The conventional index of drug sensitivity is the AUC of the DRC. In this study, the CODRP index for drug sensitivity test was proposed through multi-parameter analyses considering cancer cell proliferation rate, the cancer diagnosis stage, and AUC values. We tested PDOs from eight patients with lung cancer to verify the CODRP index. According to the anaplastic lymphoma kinase (ALK) rearrangement status, the conventional AUC index for the three ALK-targeted drugs (crizotinib, alectinib, and brigatinib) did not classify into sensitive and resistant groups. The proposed CODRP index-based drug sensitivity test classified ALK-targeted drug responses according to ALK rearrangement status and was verified to be consistent with the clinical drug treatment response. Conclusions: Therefore, the PDO-based HTS and CODRP index drug sensitivity tests described in this paper may be useful for predicting and analyzing promising anticancer drug efficacy for patients with lung cancer and can be applied to a precision medicine platform. [ABSTRACT FROM AUTHOR]

In radiomics research, the issue of different instruments being used is significant. In this study, we compared three correction methods to reduce the batch effects in radiogenomic data from fluorodeoxyglucose (FDG) PET/CT images of lung cancer patients. Texture features of the FDG PET/CT images and genomic data were retrospectively obtained. The features were corrected with different methods: phantom correction, ComBat method, and Limma method. Batch effects were estimated using three analytic tools: principal component analysis (PCA), the k-nearest neighbor batch effect test (kBET), and the silhouette score. Finally, the associations of features and gene mutations were compared between each correction method. Although the kBET rejection rate and silhouette score were lower in the phantom-corrected data than in the uncorrected data, a PCA plot showed a similar variance. ComBat and Limma methods provided correction with low batch effects, and there was no significant difference in the results of the two methods. In ComBat- and Limma-corrected data, more texture features exhibited a significant association with the TP53 mutation than in those in the phantom-corrected data. This study suggests that correction with ComBat or Limma methods can be more effective or equally as effective as the phantom method in reducing batch effects. [ABSTRACT FROM AUTHOR]

Background: Efforts have been made to reduce the risk of chronic obstructive pulmonary disease (COPD) exacerbations using a variety of measures. Broncho-Vaxom (BV) is an immunomodulating agent that has shown potential benefit by balancing between immune stimulation and regulation in patients with COPD. In this study, we evaluated the clinical efficacy of BV for reducing the risk of COPD exacerbations. Methods: This study was based on the Korean National Health Insurance database, which contains reimbursement information for almost the entire population of South Korea. We extracted data from 2016 to 2019 for patients started on BV during 2017–2018. We collected baseline data on demographics, comorbidities, inhaler use, hospital type, and insurance type 1 year before starting BV. We also analyzed exacerbation history, starting from the year before BV initiation. Results: In total, 238 patients were enrolled in this study. Their mean age was 69.2 ± 9.14 years, 79.8% were male, and 45% experienced at least one exacerbation. BV reduced the risk of moderate (odds ratio [OR] = 0.59, 95% confidence interval [CI]: 0.38–0.91) and moderate-to-severe exacerbations compared to pre- and post-BV (OR = 0.571, 95% CI: 0.37–0.89). BV use also reduced the incidence of moderate and moderate-to-severe exacerbations (incidence rate ratio [IRR] = 0.75, p = 0.03; and IRR = 0.77, p = 0.03, respectively). The use of BV was significantly delayed moderate exacerbations (hazard ratio = 0.68, p = 0.02), but not with moderate-to-severe or severe exacerbations. Conclusion: The use of BV was associated with fewer moderate and moderate-to-severe exacerbations. Additionally, BV was associated with a delay in moderate COPD exacerbations. [ABSTRACT FROM AUTHOR]

Simple Summary: Lung cancer is a leading cause of death worldwide, and it's crucial to know severity of cancer and predict its prognosis. Our study focused on using a special type of scan known as FDG PET/CT to predict how well patients with a specific type of lung cancer, called adenocarcinoma, would fare after surgery. The study looked at 432 patients and analyzed various factors like age, sex, and certain imaging parameters of the tumors. Our key finding was that the metabolic tumor volume of tumor was powerful indicator of prognosis after surgery. This information was even more accurate when combined with TNM staging, existing methods used to stage cancer. Therefore, these scans could provide doctors with valuable information to plan better treatments. This development has the potential to improve survival rates and quality of life for lung adenocarcinoma patients. Introduction: FDG PET/CT is a robust imaging modality to diagnose and stratify prognoses for non-small cell lung carcinoma. However, the role of FDG PET/CT in operable lung adenocarcinoma patients has not been previously investigated in a large cohort with varying pathological stages. The prognostic value of volumetric parameters based on FDG PET/CT was investigated in patients with stage I–III lung adenocarcinoma receiving curative surgery. Methods: This retrospective study included 432 patients with lung adenocarcinoma undergoing preoperative FDG PET/CT between January 2016 and December 2017. Clinicopathologic variables, conventional image parameters, such as the maximum standardized uptake value (SUVmax) and mean SUV (SUVmean) of the primary tumor, and volumetric parameters, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG), were included in Cox regression analysis. Subgroup analysis was conducted to compare hazard ratios (HRs) based on MTV in each pathological stage. A new staging system including volumetric parameters was suggested. Results: A total of 432 patients (median age: 62 years; interquartile range: 56–70 years; 225 males) were evaluated. Sex, age, presence of EGFR mutation, pathological stage, MTV, and TLG of the primary tumor were selected as statistically significant prognostic factors for overall survival irrespective of other variables (OS; p < 0.05 for all). Pathological stage, MTV, and TLG of the primary tumor were selected as statistically significant prognostic factors for disease-free survival irrespective of other variables (p < 0.05 for all). The suggested new staging system including MTV as an additional criterion showed better discrimination and prediction for OS than the conventional pathological staging system despite statistical insignificance (concordance index: 0.698 vs. 0.673). Conclusions: The volumetric parameters of the primary tumor based on preoperative FDG PET/CT were independent prognostic factors in addition to pathological stage in patients with operable lung adenocarcinoma. The suggested new staging system considering MTV predicted the prognoses better than the conventional pathological staging system. [ABSTRACT FROM AUTHOR]

Simple Summary: The pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) is a surrogate endpoint for predicting long-term clinical benefit in breast cancer. Recently, the use of radiomic features extracted from 18F-FDG PET/CT has emerged as a promising tool for predicting treatment outcomes in various cancers. We developed and externally validated a predictive model using 18F-FDG PET-based radiomics with the least absolute shrinkage and selection operator (LASSO) logistic method for pCR following NAC in breast cancer. Our radiomic-score model demonstrated satisfactory discriminative performances in training, internal validation, and external validation cohorts. Furthermore, the integrated radiomic model incorporating human epidermal growth factor receptor 2 (HER2) status showed improved performance compared to the radiomic-score model alone in all cohorts. The newly developed radiomic-score model might enable a more accurate and personalized assessment of the tumor response to neoadjuvant chemotherapy in breast cancer. The aim of our retrospective study is to develop and externally validate an 18F-FDG PET-derived radiomics model for predicting pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) in breast cancer patients. A total of 87 breast cancer patients underwent curative surgery after NAC at Soonchunhyang University Seoul Hospital and were randomly assigned to a training cohort and an internal validation cohort. Radiomic features were extracted from pretreatment PET images. A radiomic-score model was generated using the LASSO method. A combination model incorporating significant clinical variables was constructed. These models were externally validated in a separate cohort of 28 patients from Soonchunhyang University Buscheon Hospital. The model performances were assessed using area under the receiver operating characteristic (AUC). Seven radiomic features were selected to calculate the radiomic-score. Among clinical variables, human epidermal growth factor receptor 2 status was an independent predictor of pCR. The radiomic-score model achieved good discriminability, with AUCs of 0.963, 0.731, and 0.729 for the training, internal validation, and external validation cohorts, respectively. The combination model showed improved predictive performance compared to the radiomic-score model alone, with AUCs of 0.993, 0.772, and 0.906 in three cohorts, respectively. The 18F-FDG PET-derived radiomic-based model is useful for predicting pCR after NAC in breast cancer. [ABSTRACT FROM AUTHOR]

Background: Technetium-99 m 3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) and technetium-99 m sodium pyrophosphate (PYP) are the two most commonly used radiotracers for cardiac amyloidosis (CA), but no studies have directly compared them. Therefore, in this study, we directly compared the diagnostic and clinical utility of DPD and PYP scintigraphy in patients with CA. Methods: Ten patients with CA were enrolled. Eight clinical variables and 12 scintigraphic parameters were used. Clinical variables were age, sex, estimated glomerular filtration rate (eGFR), N-terminal pro brain natriuretic peptide (NT-proBNP), and the results of electromyography (EMG), a sensory test, electrocardiogram, and echocardiography (EchoCG). Four heart retention ratios (heart/whole-body profile, heart/pelvis, heart/skull, and heart/contralateral lung) were calculated from the DPD and PYP scans and two visual scoring systems (Perugini and Dorbala systems) were used. Comparative analyses were performed between radiotracers and between visual scoring systems using clinical variables and scintigraphic parameters. Results: Twenty DPD parameters and nine PYP parameters had significant associations with age, eGFR, NT-proBNP, EchoCG, and EMG. DPD parameters had more frequent significant associations with clinical variables than PYP parameters. Compared to visual scores in the DPD scan, the proportion of patients with higher visual scores in the PYP scan was relatively greater than those with lower visual scores, and there were more patients with a visual score of 2 or higher in PYP scans than DPD scans. Conclusions: DPD scintigraphy may reflect the disease severity of CA better than PYP scintigraphy, whereas PYP scintigraphy may be a more sensitive imaging modality for identifying CA involvement. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to investigate the association between methionine (MET) metabolism and endocrine function of the pituitary gland in patients with suprasellar region tumor. Materials and methods: Twenty patients with intracranial germinoma were included in this study. Initial staging and all surveillance MET PET/CT scans and comparable serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), and thyroid stimulating hormone (TSH) were analyzed. The patients were divided into two groups according to tumor location, with tumors in the suprasellar region (condition) or not (control). MET uptake of the pituitary gland (i.e., SUVR [standardized uptake value ratio]) and levels of FSH, LH, TSH were compared in the condition and control groups and in the before and after treatment phases of each group. Results: The SUVR in the control group was like that found in normal pituitary glands in previous studies, whereas the SUVR of the untreated condition group was high and that of treated condition group was low with significance compared to the control group. Serum levels of pituitary hormones in before and after treatment condition groups were significantly lower than those in the control group. The FSH and LH levels of curatively treated patients in the control group were positively correlated with SUVR with respective ß values of 3.71 and 0.98 (p <.001). The TSH level of the treated condition group was negatively correlated with SUVR (ß = -1.02, p <.001). Conclusion: This study is the first known investigation to examine the association between MET metabolism and endocrine function of the pituitary gland, and it confirmed that MET metabolism reflects endocrine function. A future study validating the result of correlation analysis is warranted. [ABSTRACT FROM AUTHOR]

Simple Summary: Although ER expression levels affect the prognosis of breast cancer, studies about PR expression levels are insufficient. Furthermore, there is a knowledge gap between single HR-positive and double HR-positive, especially according to PR expression. As HR positivity is an important prognostic factor, particularly in YBC patients, this research was conducted in a prospective cohort with only YBC patients in order to find out whether the expression of PR modifies the clinical course of breast cancer. We investigated clinicopathologic features and prognosis of ER-positive/HER2-negative breast cancer after stratifying them according to PR expression levels. Conclusively, low PR expression was correlated with worse clinicopathologic characteristics, and associated with increased risk of recurrence, distant metastasis, and death compared with strong PR expression group. Low PR might be a prognostic factor of ER-positive/HER2-negative YBC. Background: Although estrogen receptor (ER) expression levels affect the prognosis of breast cancer, studies about progesterone receptor (PR) expression levels are insufficient, especially in young breast cancer (YBC). The purpose of this study was to compare clinical characteristics and prognosis according to PR expression levels in invasive breast cancer patients. Methods: A prospective cohort study was conducted to identify YBC patients with invasive carcinoma diagnosed at an age of less than 40 years old between 2013 and 2018. Clinicopathologic features and prognosis of ER-positive and human epidermal growth factor receptor 2 (HER2)-negative patients were investigated. Patients were stratified into strong PR (PR-positive cell proportion > 10%), low PR (PR-positive cell proportion = 1~10%), and PR-negative (PR-positive cell proportion < 1%). Results: Among 458 patients enrolled, 386 (84.3%), 26 (5.7%), and 46 (10.0%) were categorized into strong PR, low PR, and PR-negative groups, respectively. The median follow-up duration was 58.6 months. Compared with the strong PR group, low PR and PR-negative groups were more likely to have high Ki-67 and a high nuclear grade. Low R and PR-negative groups had significantly worse disease-free survival (DFS) and distant metastasis-free survival (DMFS) than the strong PR group (p = 0.0033, p = 0007). Low PR group had an even higher risk of distant metastasis than PR-negative patients. Low PR patients and PR-negative had significantly lower overall survival (OS) rates than strong PR. Conclusion: Low PR might be a prognostic factor of ER-positive/HER2-negative in YBC. [ABSTRACT FROM AUTHOR]

Positron emission tomography/computed tomography (PET/CT) with 18F-fluorodeoxyglucose (FDG) is widely used for management of nasopharyngeal carcinoma (NPC). Combining the radiomic features of pre- and post-treatment FDG PET images may improve tumor characterization and prognostic predication. We investigated prognostic value of radiomic features from pre- and post-radiotherapy FDG PET images in patients with NPC. Quantitative radiomic features of primary tumors were extracted from the FDG PET images of 145 NPC patients and the delta values were also calculated. The study population was divided randomly into two groups, the training and test sets (7:3). A random survival forest (RSF) model was adopted to perform analyses of progression-free survival (PFS) and overall survival (OS). There were 37 (25.5%) cases of recurrence and 16 (11.0%) cases of death during a median follow-up period of 54.5 months. Both RSF models with clinical variables and radiomic PET features for PFS and OS showed comparable predictive performance to RSF models with clinical variables and conventional PET parameters. Tumoral radiomic features of pre- and post-treatment FDG PET and the corresponding delta values may predict PFS and OS in patients with NPC. [ABSTRACT FROM AUTHOR]

F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is a robust imaging modality used for staging multiple myeloma (MM) and assessing treatment responses. Herein, we extracted features from the FDG PET/CT images of MM patients using an artificial intelligence autoencoder algorithm that constructs a compressed representation of input data. We then evaluated the prognostic value of the image-feature clusters thus extracted. Conventional image parameters including metabolic tumor volume (MTV) were measured on volumes-of-interests (VOIs) covering only the bones. Features were extracted with the autoencoder algorithm on bone-covering VOIs. Supervised and unsupervised clustering were performed on image features. Survival analyses for progression-free survival (PFS) were performed for conventional parameters and clusters. In result, supervised and unsupervised clustering of the image features grouped the subjects into three clusters (A, B, and C). In multivariable Cox regression analysis, unsupervised cluster C, supervised cluster C, and high MTV were significant independent predictors of worse PFS. Supervised and unsupervised cluster analyses of image features extracted from FDG PET/CT scans of MM patients by an autoencoder allowed significant and independent prediction of worse PFS. Therefore, artificial intelligence algorithm–based cluster analyses of FDG PET/CT images could be useful for MM risk stratification. [ABSTRACT FROM AUTHOR]

Simple Summary: With increasing incidence of breast cancer and improvement in treatment, the concern about surveillance management after curative treatment in patients with breast cancer also has increased. However, there is a debate regarding routine surveillance follow-up examinations in clinical practice. This retrospective study was designed to evaluate the diagnostic value of routine surveillance FDG PET/CT in patients with breast cancer. A total of 2121 scans in 1681 women with breast cancer in surveillance were included in the study. The frequency of positive surveillance PET/CT findings was 5.0% (105 of 2121 scans) and the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for detecting clinically unsuspected recurrent breast cancer or second primary malignancy were 100%, 98.5%, 70.5%, 100% and 98.5%, respectively. In conclusion, surveillance fluorodeoxyglucose PET/CT showed superior diagnostic performance and comparable rate of positive findings with conventional imaging modality in the detection of clinically unexpected recurrent breast cancer after curative treatment. With increasing incidence of breast cancer and improvement in treatment, the concern about surveillance management also has increased. This retrospective study was designed to evaluate the diagnostic value of routine surveillance FDG PET/CT in patients with breast cancer. The diagnostic performance of surveillance PET/CT was analyzed regarding sensitivity, specificity, positive predictive value, negative predictive value and accuracy. The diagnostic accuracy was defined as the ability to differentiate recurrence and no-disease correctly and the proportion of true results, either true positive or true negative, in the population. Findings from pathologic examination; other imaging modalities such as CT, MRI and bone scan; or clinical follow-up were used as the reference standard. In this study of 1681 consecutive patients with breast cancer who underwent curative surgery, surveillance fluorodeoxyglucose PET/CT showed good diagnostic performance in the detection of clinically unexpected recurrent breast cancer or other malignancy, with a sensitivity of 100%, specificity of 98.5%, positive predictive value of 70.5%, negative predictive value of 100% and accuracy of 98.5%. In conclusion, surveillance fluorodeoxyglucose PET/CT showed good diagnostic performance in the detection of clinically unexpected recurrent breast cancer after curative surgery. [ABSTRACT FROM AUTHOR]

Background: Characteristics of AL amyloidosis across Asia are not well-described in the literature. Thus, we overviewed the incidence and disease characteristics of AL amyloidosis in Korea. Methods: We collected medical records of 302 AL amyloidosis patients and compared survival outcomes by predominant treatment strategy and at four time points: 1995–2003, 2004–2008, 2009–2013, and 2014–2018. Results: The median age was 62 years (36–83). One hundred forty-one patients were classified as stage III (26.3%) or IV (47.9%). The patients diagnosed between 2014 and 2018 survived longer than those diagnosed at other time points due to the introduction of bortezomib (p < 0.01). In addition, patients who received upfront ASCT survived longer than those who received salvage ASCT or chemotherapy alone (p < 0.01). However, most of the 85 patients who experienced early death within 6 months were older than 75 years, had BMI less than 20, and had a high disease burden. Conclusions: The incidence of AL amyloid has increased and survival outcomes have improved gradually, most likely due to introduction of novel agents and upfront ASCT. However, not all patients are suitable for these potent treatment modalities, and avoiding early death within 6 months remains a challenge. [ABSTRACT FROM AUTHOR]

Background: A considerable proportion of patients have features of both asthma and chronic obstructive pulmonary disease (COPD) simultaneously, called asthma–COPD overlap (ACO). Objectives: The aim of this study was to identify heterogeneity of ACO from a cohort of patients with severe asthma and COPD using the same diagnostic criteria. Design: We used the International Severe Asthma Registry (ISAR) and the Korean COPD Subgroup Study (KOCOSS) to evaluate clinical characteristics of ACO from each cohort. Methods: We classified subjects into four groups: (1) pure severe asthma, (2) ACO from the severe asthma cohort, (3) ACO from the COPD cohort, and (4) pure COPD. ACO was defined by satisfying extreme bronchodilator response (BDR) >15% and 400 ml and/or blood eosinophil count ⩾300 /µL in patients aged 40 years or older and post-BD forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio <0.7. Results: The ACO group had 25 (23%) of 111 in the ISAR cohort and 403 (23%) of 1781 in the KOCOSS cohort. The ACO from the COPD cohort was older with more males and more smokers, but had similar degree of airflow limitation compared with the ACO from the severe asthma cohort. ICS-containing inhaler treatment was prescribed for all severe asthma subjects, but only for 43.9% of ACO subjects from the COPD cohort. Compared with patients having pure severe asthma, the risk for exacerbation was comparable in ACO either from severe asthma or COPD cohort [adjusted odds ratio (aOR): 1.54, 95% CI: 0.22–10.95 or aOR: 2.15, 95% CI: 0.59–7.85]. Conclusion: The prevalence of ACO was similar in severe asthma and COPD cohorts applying identical diagnostic criteria. ACO from the severe asthma cohort was similar to ACO from the COPD cohort in terms of lung function and exacerbation risk. [ABSTRACT FROM AUTHOR]

Simple Summary: The estimation of overall survival (OS) in patients with stage III non-small cell lung cancer (NSCLC) is very important for determining a precise therapeutic strategy. Radiomics is a promising method to extract features that can reflect distinct differences in tumor phenotype from image data. We evaluated the prognostic impact of the radiomic features from 18F-FDG PET/CT to predict OS in patients with stage III NSCLC undergoing neoadjuvant concurrent chemoradiation therapy (CCRT) followed by surgery and compared the predictive performance of radiomics versus conventional PET parameters. We demonstrated that radiomic features using 18F-FDG PET/CT could be robust and useful in assessing the survival rate. Furthermore, this study demonstrated the important prognostic implications of radiomics in 18F-FDG PET/CT after neoadjuvant CCRT as well as pretreatment examination. The newly developed LASSO score using radiomic features performs better for individualized OS estimation than conventional PET parameters. We investigated the prognostic significance of radiomic features from 18F-FDG PET/CT to predict overall survival (OS) in patients with stage III NSCLC undergoing neoadjuvant chemoradiation therapy followed by surgery. We enrolled 300 patients with stage III NSCLC who underwent PET/CT at the initial work-up (PET1) and after neoadjuvant concurrent chemoradiotherapy (PET2). Radiomic primary tumor features were subjected to LASSO regression to select the most useful prognostic features of OS. The prognostic significance of the LASSO score and conventional PET parameters was assessed by Cox proportional hazards regression analysis. In conventional PET parameters, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of each PET1 and PET2 were significantly associated with OS. In addition, both the PET1-LASSO score and the PET2-LASSO score were significantly associated with OS. In multivariate Cox regression analysis, only the PET2-LASSO score was an independently significant factor for OS. The LASSO score showed better predictive performance for OS regarding the time-dependent receiver operating characteristic curve and decision curve analysis than conventional PET parameters. Radiomic features from PET/CT were an independent prognostic factor for the estimation of OS in stage III NSCLC. The newly developed LASSO score using radiomic features showed better prognostic results for individualized OS estimation than conventional PET parameters. [ABSTRACT FROM AUTHOR]

Th2 inflammation is associated with various characteristics of patients with chronic obstructive pulmonary disease (COPD). In this study, we analyzed the COPD exacerbation risk associated with serum levels of interleukin (IL)-25/thymic stromal lymphopoietin (TSLP) and eosinophils. We studied the KOCOSS cohort, a multicenter COPD cohort created by 54 medical centers in South Korea. We extracted data collected between April 2012 and August 2020. We measured serum levels of TSLP and IL-25 in those who agreed to provide blood, and assessed exacerbation risk according to each. In all, 562 patients were enrolled. The IL-25-high group had a lower St. George's Respiratory Questionnaire score than others, and the TSLP-high group had a poorer exercise capacity than the TSLP-low group. There were no significant differences in the forced expiratory volume in 1 s (FEV1), the levels of Th2 inflammatory biomarkers, or the exacerbation histories between the two groups. The 3-year decline in FEV1 was not significantly affected by IL-25 or TSLP levels. In terms of 1-year exacerbation risk, individuals in the IL-25-high group were at lower risk for moderate-to-severe exacerbation than others. A high TSLP level was associated with a lower risk of severe exacerbation but only in the eosinophil-low group. Serum levels of IL-25 are negatively correlated with moderate-to-severe exacerbation risk in this cohort. A negative correlation between severe exacerbation risk and TSLP level was apparent only in the eosinophil-low group. [ABSTRACT FROM AUTHOR]

Background: The clinical implication of bronchodilator response (BDR) is not fully understood. However, BDR is frequently present in patients with chronic obstructive pulmonary disease (COPD). We identified the differences in clinical features regarding BDR. In addition, we divided BDR into BDR for forced expiratory volume in 1 s (FEV1) and BDR for forced vital capacity (FVC; i.e., BDR-FEV1 and BDR-FVC, respectively) and analyzed clinical significance. Methods: We used data from the Korea COPD Subgroup Study, a multicenter cohort study of COPD patients recruited from 54 centers in South Korea since April 2012. We analyzed differences in baseline characteristics, 1-year exacerbation rate, and 3-year FEV1 decline between BDR negative and positive patients. Moreover, we analyzed the differences in clinical features between BDR-FEV1 positive and negative patients and between BDR-FVC positive and negative patients. Results: Of the 2,181 patients enrolled in this study, 366 (16.8%) were BDR positive. BDR positive patients were more likely to be ever-smokers and to have a lower body mass index and higher symptom scores compared to BDR negative patients. Baseline FEV1 and FEV1/FVC were lower in the BDR positive compared to the BDR negative group (1.7 ± 0.6 and 1.6 ± 0.5, respectively, p < 0.01; 50.9 ± 12.1 and 46.5 ± 14.8, respectively, p < 0.01). BDR positive patients were more likely to have been diagnosed with asthma–COPD overlap and to receive inhaled corticosteroids (ICS) than BDR negative patients. BDR-FVC patients were more likely to be smokers, suffer from worse symptoms and have lower lung function than those with no BDR-FVC. BDR had no significant effect on 1-year moderate to severe or severe exacerbation rates or 3-year annual FEV1 decline. Interactive effects of ICS and BDR on the exacerbation rate were not significant in any group. Conclusions: In this study, BDR positive patients were more likely to be ever-smokers and to have worse symptoms and lung function than BDR negative patients. BDR-FVC was associated with worse symptom control and lung function compared to BDR-FEV1. However, there were no significant differences in exacerbation rate or decline in lung function in any BDR group. In addition, the effects of ICS on exacerbations were not significant in any group. [ABSTRACT FROM AUTHOR]

Encoder interfaces should be operated in real time with high precision and fast processing for industrial motor control systems. The continuous bidirectional serial synchronous (BiSS-C) interface is an open-source serial communication protocol designed for motor encoders and is suitable for industrial purposes because of its fast serial communication speed. In this study, we propose a method for developing a BiSS-C interface master for a motor encoder slave, using only the configurable logic block (CLB) peripheral integrated into TI microcontroller units. By analyzing the detailed operation protocol of the BiSS-C interface, we create the truth and state tables for logic circuits and finite state machines, which are required for the BiSS-C interface master. Then, by programming the CLB based on the created truth and state tables, we implement the master clock, serial peripheral interface (SPI) clock, and operational process for the master. This approach is cost-efficient because additional hardware components, such as a field-programmable gate array or a complex programmable logic device, are not required for the master implementations. The developed method can be immediately applied to developing the masters for other BiSS-C encoders with different specifications, which is certainly necessary for a motor drive development and test. By building an AC motor control system with the developed master and performing various experiments, we verify the performance and practical usefulness of the developed BiSS-C interface master. The maximum master clock frequency without any CRC errors is achieved by 6.25 MHz, which can cope with more than 20 kHz motor control cycle frequency. The usefulness is demonstrated by showing the motor speed and position control performance that are acceptable in real applications. [ABSTRACT FROM AUTHOR]

Pulmonary lymphangitic carcinomatosis (PLC) is associated with a poor prognosis in patients with non-small cell lung cancer (NSCLC). We sought to determine prognostic value of pretherapeutic fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in NSCLC with radiologically diagnosed PLC. We retrospectively reviewed 50 NSCLC patients with radiologically diagnosed PLC. Among eight clinical variables and five imaging parameters, metabolic PLC burden, which represents the overall tumor burden of PLC, and cPLC, which represents the location and extent of PLC in a three-grade system, were used. In multivariate analyses for progression-free survival, metabolic PLC burden (P = 0.0181), cPLC (P = 0.0401), and clinical stage (P = 0.0284) were identified as independent prognostic factors. High metabolic PLC burden had a worse prognosis, and the prognosis of cPLC3 was significantly worse than that of cPLC1 or cPLC2. In univariate analyses for overall survival, only age (P = 0.0073) was identified a prognostic factor. In conclusion, FDG PET/CT parameters were identified as independent prognostic factors in NSCLC with radiologically diagnosed PLC. Furthermore, a combination of anatomical and metabolic information about PLC obtained using FDG PET/CT provides insight into the overall tumor burden of PLC and is useful in predicting prognosis. [ABSTRACT FROM AUTHOR]

Background: Comorbidities of chronic obstructive pulmonary disease (COPD) influence clinical characteristics and prognosis. Objectives: This study compared the clinical characteristics and exacerbation rate of COPD according to the presence of depression or anxiety. Design: This study used data from The Korea COPD Subgroup Study (KOCOSS) cohort, a nationwide prospective cohort from 54 medical centers, between April 2012 and 2019. Methods: Depression and anxiety were diagnosed with the Beck Depression Inventory and Beck Anxiety Inventory. Negative binomial regression analysis was performed to analyze the frequency of exacerbations in depressed patients and anxiety. Differences in lung function trajectory according to presence of depression/anxiety were analyzed using a linear mixed model. Results: In all, 2147 patients were enrolled. Depressed patients or anxiety had lower lung function, higher modified Medical Research Council (mMRC) grade, St. George Respiratory Questionnaire (SGRQ) score, and COPD assessment test score, and higher rates of exacerbation in the past year than those without depression/anxiety. Depressed patients had a higher frequency of moderate to severe exacerbations [Incidence Rate Ratio (IRR): 1.57, CI: 1.17-2.11, p = 0.002] and those with anxiety had higher frequencies of moderate to severe (IRR: 1.52, CI: 1.03-2.27, p = 0.038) and severe exacerbations (IRR: 2.13, CI: 1.09-4.15, p = 0.025) during 1-year follow-up compared to those without these comorbidities. The differences in the change in annual forced expiratory volume in 1 seconds (FEV1) over 3 years according to the presence of depression or anxiety were not statistically significant. Conclusion: Depressed and anxious patients showed increased respiratory symptoms and exacerbation rate as well as reduced health-related quality of life, whereas there were no significant differences in changes in lung function between groups with and without depression/anxiety. [ABSTRACT FROM AUTHOR]

Background: A considerable proportion of patients have features of both asthma and chronic obstructive pulmonary disease (COPD) simultaneously, called asthma-COPD overlap (ACO). Objectives: The aim of this study was to identify heterogeneity of ACO from a cohort of patients with severe asthma and COPD using the same diagnostic criteria. Design: We used the International Severe Asthma Registry (ISAR) and the Korean COPD Subgroup Study (KOCOSS) to evaluate clinical characteristics of ACO from each cohort. Methods: We classified subjects into four groups: (1) pure severe asthma, (2) ACO from the severe asthma cohort, (3) ACO from the COPD cohort, and (4) pure COPD. ACO was defined by satisfying extreme bronchodilator response (BDR) >15% and 400 ml and/or blood eosinophil count ⩾300 /µL in patients aged 40 years or older and post-BD forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio >0.7. Results: The ACO group had 25 (23%) of 111 in the ISAR cohort and 403 (23%) of 1781 in the KOCOSS cohort. The ACO from the COPD cohort was older with more males and more smokers, but had similar degree of airflow limitation compared with the ACO from the severe asthma cohort. ICS-containing inhaler treatment was prescribed for all severe asthma subjects, but only for 43.9% of ACO subjects from the COPD cohort. Compared with patients having pure severe asthma, the risk for exacerbation was comparable in ACO either from severe asthma or COPD cohort [adjusted odds ratio (aOR): 1.54, 95% CI: 0.22-10.95 or aOR: 2.15, 95% CI: 0.59-7.85]. Conclusion: The prevalence of ACO was similar in severe asthma and COPD cohorts applying identical diagnostic criteria. ACO from the severe asthma cohort was similar to ACO from the COPD cohort in terms of lung function and exacerbation risk. [ABSTRACT FROM AUTHOR]

We evaluated whether the pathogens identified during acute exacerbation of chronic obstructive pulmonary disease (AE-COPD) are associated with the COPD medications used in the 6 months before AE-COPD. We collected the medical records of patients diagnosed with AE-COPD at 28 hospitals between January 2008 and December 2019 and retrospectively analyzed them. Microorganisms identified at the time of AE-COPD were analyzed according to the use of inhaled corticosteroid (ICS) and systemic steroid after adjusting for COPD severity. We evaluated 1177 patients with AE-COPD and available medication history. The mean age of the patients was 73.9 ± 9.2 years, and 83% were males. The most frequently identified bacteria during AE-COPD were Pseudomonas aeruginosa (10%), followed by Mycoplasma pneumoniae (9.4%), and Streptococcus pneumoniae (5.1%), whereas the most commonly identified viruses were rhinovirus (11%) and influenza A (11%). During AE-COPD, bacteria were more frequently identified in the ICS than non-ICS group (p = 0.009), and in the systemic steroid than non-systemic steroid group (p < 0.001). In patients who used systemic steroids before AE-COPD, the risk of detecting Pseudomonas aeruginosa was significantly higher during AE-COPD (OR 1.619, CI 1.007–2.603, p = 0.047), but ICS use did not increase the risk of Pseudomonas detection. The risk of respiratory syncytial virus (RSV) detection was low when ICS was used (OR 0.492, CI 0.244–0.988, p = 0.045). COPD patients who used ICS had a lower rate of RSV infection and similar rate of P. aeruginosa infection during AE-COPD compared to patients who did not use ICS. However, COPD patients who used systemic steroids within 6 months before AE-COPD had an increased risk of P. aeruginosa infection. Therefore, anti-pseudomonal antibiotics should be considered in patients with AE-COPD who have used systemic steroids. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the CT and PET-CT features of solitary pulmonary capillary hemangioma (SPCH) with clinicopathologic correlations. This retrospective study included 17 patients with histologically proven SPCH from four tertiary institutions. The clinical, pathological and imaging findings of SPCH were reviewed. The CT features assessed included lesion location, size, density, contour, margin, enhancement, presence of air bronchogram, perivascular lucency and pleural retraction, and 18F-fluorodeoxyglucose uptake on PET-CT. Changes in the size during the follow-up period were also evaluated. Imaging features were correlated with the clinicopathologic findings. The mean age of the patients was 47 years (range 30–60 years). All SPCHs were incidentally detected during screening CT examinations (n = 13, 76%) or during cancer work-up (n = 4, 24%). Most SPCHs appeared as part-solid nodules (n = 15, 88%), the remaining appeared as a pure ground-glass nodule or a pure solid nodule, respectively. Most had smooth contours (n = 16, 94%), while one had a lobulated contour. Nine SPCHs (53%) showed ill-defined margins. Air bronchogram was present in ten (59%) SPCHs, and perivascular lucency in two (12%). All SPCHs exhibited hypoattenuation on contrast-enhanced CT and hypometabolism on PET-CT. During the follow-up period (mean 14.8 ± 17.7 months), the lesions showed no change in size or density in ten SPCHs (59%), decreased or fluctuation in size and density in three (18%). SPCH is often incidentally detected in young and middle-aged adults, commonly as an ill-defined part-solid nodule that may accompany air bronchogram, perivascular lucency, and fluctuation in size or density on CT and hypometabolism on PET-CT. [ABSTRACT FROM AUTHOR]

Background: This study investigated the prognostic value of axillary lymph node (ALN) heterogeneity texture features through 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in patients with locally advanced breast cancer (LABC). Methods: We retrospectively analyzed 158 LABC patients with FDG-avid, pathology-proven, metastatic ALN who underwent neoadjuvant chemotherapy (NAC) and curative surgery. Tumor and ALN texture parameters were extracted from pretreatment 18F-FDG PET/CT using Chang-Gung Image Texture Analysis software. The least absolute shrinkage and selection operator regression was performed to select the most significant predictive texture parameters. The predictive impact of texture parameters was evaluated for both progression-free survival and pathologic NAC response. Results: The median follow-up period of 36.8 months and progression of disease (PD) was observed in 36 patients. In the univariate analysis, ALN textures (minimum standardized uptake value (SUV) (p = 0.026), SUV skewness (p = 0.038), SUV bias-corrected Kurtosis (p = 0.034), total lesion glycolysis (p = 0.011)), tumor textures (low-intensity size zone emphasis (p = 0.045), minimum SUV (p = 0.047), and homogeneity (p = 0.041)) were significant texture predictors. On the Cox regression analysis, ALN SUV skewness was an independent texture predictor of PD (p = 0.016, hazard ratio 2.3, 95% confidence interval 1.16–4.58). Conclusions: ALN texture feature from pretreatment 18F-FDG PET/CT is useful for the prediction of LABC progression. [ABSTRACT FROM AUTHOR]

Hepsin, a cell surface serine protease, is a potential biomarker for the detection of prostate cancer due to its high expression in prostate cancer but not in normal prostate. This study aimed to develop a radioligand for positron emission tomography (PET) imaging of hepsin. Six leucine–arginine (Leu–Arg) dipeptide derivatives (two diastereomers for each of three ligands) were synthesized and evaluated for their binding affinities and selectivity for hepsin. Based on the binding assay, a natCu-1,4,7,10-tetraazacyclododecane-N,N′,N″,N‴-tetraacetic acid (DOTA)-conjugated ligand (3B) was selected for the development of a PET radioligand. [64Cu]3B was synthesized by labeling the DOTA-conjugated compound 11B with [64Cu]CuCl2 at 80 °C for 20 min. The radioligand was evaluated for prostate cancer cell binding and PET imaging in a prostate tumor mouse model. The results demonstrated that [64Cu]3B exhibited high binding to LNCaP cells, intermediate binding to 22Rv1 cells, and low binding to PC3 cells. PET studies of [64Cu]3B in mice, implanted with 22Rv1 and PC3 cells on each flank, revealed that the radioligand uptake was high and persistent in the 22Rv1 tumors over time, whereas it was low in PC3 tumors. The results of this study suggest that [64Cu]3B is a promising PET radioligand for hepsin imaging. [ABSTRACT FROM AUTHOR]

Simple Summary: Although texture parameters of F-18 fluorodeoxyglucose positron emission tomography/computed tomography images were known to associate tumor biology and clinical features, the types and implications of parameters are too various and complicated. To overcome the limitation of texture parameter, we attempted to produce a new simplified parameter from texture parameters of F-18 fluorodeoxyglucose positron emission tomography/computed tomography images in lung cancer patients using pseudotime analysis. Pseudotime analysis is a recently developed method to explore changes in cell or tissue characteristics based on transcriptomic expression. It is the first study to apply pseudotime analysis into radiomics dataset other than transcriptomics data. Herein, we demonstrated that pseudotime can be successfully estimated from texture parameters. In the aspect of prognostic prediction, pseudotime was an independent prognostic factor for overall survival in contrast to conventional parameters such as metabolic tumor volume and total lesion glycolysis. This study showed possibility of integrating various texture parameters into single parameter which reflects disease progression status. Pseudotime, as a concrete value of disease progression, is expected to be used in clinical field to evaluate disease and predict prognosis. Texture analysis provides image parameters from F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). Although some parameters are associated with tumor biology and clinical features, the types and implications of these parameters are complicated. We applied pseudotime analysis, which has recently been used to estimate changes in individual sample characteristics, to texture parameters from FDG PET/CT images of locally advanced non-small-cell lung cancer (NSCLC) patients undergoing neoadjuvant concurrent chemoradiation therapy (CCRT) followed by surgery. Our subjects were 303 NSCLC patients who underwent pretherapeutic FDG PET/CT and tri-modality therapy. Texture parameters of the primary tumor were calculated from FDG PET/CT images acquired before neoadjuvant CCRT. Pseudotime analysis was performed using the PhenoPath tool. Clinicopathologic features including survival data were collected and survival analysis was performed to compare the prognostic significances of pseudotime parameters with those of conventional PET parameters. Pseudotime was successfully estimated from texture parameters. Normalized co-occurrence homogeneity, normalized co-occurrence inverse difference moment, and black–white symmetry showed positive correlations with pseudotime, short run emphasis, normalized co-occurrence dissimilarity, and short zone emphasis negative correlation. The maximum standardized uptake value (SUV) and mean SUV were not associated with overall survival. Pseudotime, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) showed significant associations with overall survival. In contrast to MTV and TLG, pseudotime was an independent prognostic factor for overall survival. Various metabolic texture parameters can be integrated into a single parameter using pseudotime analysis. Pseudotime of the primary tumor, estimated from FDG PET/CT images, better predicts overall survival in locally advanced NSCLC patients treated with tri-modality therapy than conventional PET parameters. [ABSTRACT FROM AUTHOR]

Clarifying the mechanism of lymphoma-associated hyperlactatemia could help identify patients at risk. Here, 129 non-Hodgkin's lymphoma patients suspected of blood lactate elevation underwent blood measurement and 18F-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) on the same day. Blood lactate elevation was mild (1.0–2.5 mmol/L) in 60, moderate (2.5–4.0 mmol/L) in 46, and severe (≥ 4.0 mmol/L) in 23 subjects. Subjects with severe lactate elevation had higher lymphoma stage, worse IPI risk, poorer ECOG performance, and higher tumor TLG. Furthermore, there was a linear correlation between blood lactate concentration and lymphoma TLG (Spearman's r = 0.367; P < 0.0001). Brain FDG uptake was low (SUVave < 4.0) in 81 patients that were older, had greater stage and IPI risk, worse ECOG performance, and higher blood lactate. Brain SUVave showed inverse correlation with blood lactate (Spearman's r = − 0.564; P < 0.0001) and lymphoma TLG (Spearman's r = − 0.252; P = 0.0066), as well as with stage, ECOG score, and IPI risk. Multivariable regression analysis confirmed increased blood lactate and lymphoma TLG as significant explanatory variables for reduced brain SUVave (both P < 0.0001). Hence, blood lactate elevation in lymphoma patients is the result of glycolytic tumor burden. Since brain cells prefer lactate over glucose as energy source when blood lactate level is increased, this causes proportional reductions of brain FDG uptake. FDG PET/CT can therefore identify high glycolytic lymphoma burden at risk of hyperlactatemia and may provide estimates of its severity by reductions in brain uptake. [ABSTRACT FROM AUTHOR]

It is challenging to overcome difficult-to-treat asthma, and cell-based therapies are attracting increasing interest. We assessed the effects of mesenchymal stem cell (MSC) treatments using a murine model of chronic ovalbumin (OVA)-challenged asthma. We developed a murine model of chronic allergic asthma using OVA sensitization and challenge. Human adipose-derived MSCs (hADSCs) or human bone marrow-derived MSCs (hBMSCs) were administered. We measured the levels of resistin-like molecule-β (RELM-β). We also measured RELM-β in asthma patients and normal controls. OVA-challenged mice exhibited increased airway hyper-responsiveness, inflammation, and remodeling. hBMSC treatment remarkably decreased airway hyper-responsiveness but hADSC treatment did not. Both MSCs alleviated airway inflammation, but hBMSCs tended to have a more significant effect. hBMSC treatment reduced Th2-cytokine levels but hADSC treatment did not. Both treatments reduced airway remodeling. The RELM-β level decreased in the OVA-challenged control group, but increased in both treatment groups. We found that the serum level of RELM-β was lower in asthma patients than controls. MSC treatments alleviated the airway inflammation, hyper-responsiveness, and remodeling associated with chronic asthma. hBMSCs were more effective than hADSCs. The RELM-β levels increased in both treatment groups; the RELM-β level may serve as a biomarker of MSC treatment efficacy. [ABSTRACT FROM AUTHOR]

Introduction: Recently, the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) staging system was updated for its 8th edition. F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is a useful imaging tool to diagnose and predict prognoses for esophageal cancer. However, there was no previous study to explore the role of FDG PET/CT in the staging system based on the 8th edition. The prognostic value of FDG PET/CT was investigated in patients with esophageal squamous cell carcinoma (SqCC) considering the new 8th AJCC/UICC staging system. Methods: Subjects were 721 patients with esophageal SqCC undergoing pretherapeutic FDG PET/CT. Clinico-pathological variables and the maximum standardized uptake value (SUVmax) of the primary tumor were included in survival analysis. Subgroup analysis was performed to compare hazard ratios according to pathological stage and SUVmax. A new staging classification including FDG uptake was proposed. Results: In multivariate survival analysis, pathological stage and SUVmax of the primary tumor were selected as independent prognostic factors for overall survival in both the 7th and 8th editions. The proposed new staging system showed better discrimination for overall survival between stage I and II than did the conventional staging system (hazard ratios: 2.250 vs. 1.341). Conclusions: The FDG uptake of the primary tumor was found to be an independent prognostic factor along with pathological stage based on both 7th and 8th AJCC/UICC staging systems in patients with esophageal SqCC. The suggested new staging system including SUVmax was better for predicting prognoses than the conventional staging system. [ABSTRACT FROM AUTHOR]

As the burden of tuberculosis (TB) in South Korea decreases while that of malignancy increases with an aging society, the composition of etiology for pleural effusion is changing. The aim of this study was to investigate the diagnostic value of adenosine deaminase (ADA) for diagnosis of tuberculous pleural effusion (TPE) in this circumstance. Medical records of patients who underwent medical thoracoscopy from May 2015 to September 2020 in Incheon St. Mary Hospital, Korea were retrospectively reviewed. TPE was diagnosed if one of the following criteria was met: (1) granuloma in pleura, (2) positive TB polymerase chain reaction or culture in pleural fluid or tissue with non-specific pathologic findings in pleura, or (3) bacteriologically confirmed pulmonary TB with non-specific pathologic findings in pleura. A total of 292 patients, including 156 with malignant pleural effusion (MPE), 52 with TPE, and 84 with other benign effusion, were analyzed. Among 206 patients with lymphocyte dominant pleural effusion, the area under receiver characteristic curve of ADA for diagnosis of TPE was 0.971. The sensitivity and specificity of a current cutoff value of 40 IU/L were 1.00 and 0.61, respectively, whereas those of a raised cutoff value of 70 IU/L were 0.93 and 0.93, respectively. Among 54 patients with ADA levels of 40–70 IU/L, 30 (55.6%) patients were diagnosed as MPE, 21 (38.9%) as other benign effusion, and only 3 (5.6%) as TPE. Caution is needed in clinical diagnosis of TPE with current ADA cutoff value in countries with decreasing TB incidence, due to many false positive cases. [ABSTRACT FROM AUTHOR]

Simple Summary: The pathological complete response (pCR) after neoadjuvant chemoradiotherapy (CCRT) is an independent prognostic factor for progression-free and overall survival in non-small cell lung cancer (NSCLC). 18F-FDG PET/CT has been performed for initial staging work-up, treatment response, and follow-up in patients with NSCLC. Machine learning (ML) as an empirical data science has become relevant to nuclear medicine. We investigated the predictive performance of 18F-FDG PET/CT using an ML model to assess the treatment response to neoadjuvant CCRT in patients with stage III NSCLC, and compared the performance of the ML model predictions to predictions from conventional PET parameters and from physicians. The predictions from the ML model using radiomic features of 18F-FDG PET/CT provided better accuracy than predictions from conventional PET parameters and from physicians for the neoadjuvant CCRT response of stage III non-small cell lung cancer. We investigated predictions from 18F-FDG PET/CT using machine learning (ML) to assess the neoadjuvant CCRT response of patients with stage III non-small cell lung cancer (NSCLC) and compared them with predictions from conventional PET parameters and from physicians. A retrospective study was conducted of 430 patients. They underwent 18F-FDG PET/CT before initial treatment and after neoadjuvant CCRT followed by curative surgery. We analyzed texture features from segmented tumors and reviewed the pathologic response. The ML model employed a random forest and was used to classify the binary outcome of the pathological complete response (pCR). The predictive accuracy of the ML model for the pCR was 93.4%. The accuracy of predicting pCR using the conventional PET parameters was up to 70.9%, and the accuracy of the physicians' assessment was 80.5%. The accuracy of the prediction from the ML model was significantly higher than those derived from conventional PET parameters and provided by physicians (p < 0.05). The ML model is useful for predicting pCR after neoadjuvant CCRT, which showed a higher predictive accuracy than those achieved from conventional PET parameters and from physicians. [ABSTRACT FROM AUTHOR]

Neuroinflammation involves activation of glial cells in the brain, and activated microglia play a particularly important role in neurodegenerative diseases such as Alzheimer's disease (AD). In this study, we developed 5-cyano-N-(4-(4-(2-[18F]fluoroethyl)piperazin-1-yl)-2-(piperidin-1-yl)phenyl)furan-2-carboxamide ([18F]1) for PET imaging of colony-stimulating factor 1 receptor (CSF1R), an emerging target for neuroinflammation imaging. Non-radioactive ligand 1 exhibited binding affinity comparable to that of a known CSF1R inhibitor, 5-cyano-N-(4-(4-methylpiperazin-1-yl)-2-(piperidin-1-yl)phenyl)furan-2-carboxamide (CPPC). Therefore, we synthesized radioligand [18F]1 by radiofluorination of chlorine-substituted precursor 7 in 13–15% decay-corrected radiochemical yield. Dynamic PET/CT images showed higher uptake in the lipopolysaccharide (LPS)-treated mouse brain than in control mouse brain. Ex vivo biodistribution study conducted at 45 min after radioligand injection showed that the brain uptake in LPS mice increased by 78% compared to that of control mice and was inhibited by 22% in LPS mice pretreated with CPPC, indicating specificity of [18F]1 for CSF1R. A metabolism study demonstrated that the radioligand underwent little metabolism in the mouse brain. Taken together, these results suggest that [18F]1 may hold promise as a radioligand for CSF1R imaging. [ABSTRACT FROM AUTHOR]

Background: Chronic bronchitis (CB) is associated with poor outcomes in patients with chronic obstructive pulmonary disease. The aim of this study was to identify the characteristics that distinguish chronic bronchitis (CB) from non-CB. In addition, the features of mild CB versus severe CB were compared and a cut-off level was defined according to CAT1 and CAT2 scores.Methods: This study was based on the Korea COPD Subgroup Study (KOCOSS) database, constructed in a multicenter COPD cohort study that recruited patients from 54 centers. CB was defined as CAT1 and CAT2 scores ≥ 3; severe CB was defined as CAT1 and CAT2 scores ≥ 4, while mild CB was defined as either a CAT1 or a CAT2 score < 4. Baseline characteristics, 1-year exacerbation rate, and 3-year FEV1 decline were compared in non-CB versus CB patients and in patients with mild CB versus severe CB.Results: Among the 2162 patients enrolled in this study, 497 (23%) had CB. These patients were more likely than non-CB patients to be current smokers; they also had higher symptom and depression/anxiety scores. Lung function tests showed lower FEV1, FEV1/FVC, and DLco values in CB patients. Among CB patients, 67.6% had mild disease. Symptom and depression/anxiety scores were worse in patients with severe CB than in patients with mild CB. There were no significant differences in the lung function tests of the two groups. Analysis of 1-year exacerbation rates in CB patients and non-CB patients revealed that patients with CB more frequently had moderate-to-severe exacerbations (OR = 1.46, p < 0.01). More severe exacerbation was also present in patients with severe CB than in patients with mild CB (OR = 2.52, p = 0.01). The difference in annual FEV1 decline rate did not significantly differ either between CB patients and non-CB patients or between patients with severe CB and patients with mild CB.Conclusions: CB patients had worse symptoms and lung function than non-CB patients; CB patients also had more frequent moderate-to-severe exacerbation. Patients with severe CB had higher symptom scores and more frequent severe exacerbation than did patients with mild CB. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate the value of C-11 methionine (MET) positron emission tomography (PET)/computed tomography (CT) in patients with intracranial germinoma (IG). Material and methods: We conducted a retrospective analysis of 21 consecutive patients with pathologically confirmed IGs and eight patients with intracranial non-germinomas (INGs) located in a similar region. Clinical characteristics, imaging findings, and tumor markers such as α-fetoprotein (AFP) and β-human chorionic gonadotropin (HCG) were used as clinical variables. Maximum standardized uptake value (SUVmax), tumor-to-normal tissue (T/N) ratio, and visual scoring of tumor were used as MET PET parameters. Results: All IGs were well visualized on MET PET with a three-grade visual scoring system. In addition, SUVmax of IGs was higher than that of INGs (P = 0.005). Pre-treatment (Pre-Tx) T/N ratio was significantly correlated with pre-Tx serum HCG (P = 0.031). Moreover, MET PET parameters showed significant associations with tumor location, sex, KRAS variant, and symptoms. Conclusion: MET PET/CT could be a useful diagnostic tool in patients suspected of having IGs. In addition, the MET avidity of tumor is a potential surrogate biomarker of HCG, which has been used as a diagnostic marker for IGs. Tumor MET parameters also had significant differences according to tumor locations, sex, symptoms, and KRAS mutation. However, MET avidity of tumors had no significant prognostic value. [ABSTRACT FROM AUTHOR]

Introduction: The prognostic value of F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in hepatocellular carcinoma (HCC) was established in previous reports. However, there is no evidence suggesting the prognostic value of transcriptomes associated with tumor FDG uptake in HCC. It was aimed to elucidate metabolic genes and functions associated with FDG uptake, followed by assessment of those prognostic value. Methods: Sixty HCC patients with Edmondson–Steiner grade II were included. FDG PET/CT scans were performed before any treatment. RNA sequencing data were obtained from tumor and normal liver tissue. Associations between each metabolism-associated gene and tumor FDG uptake were investigated by Pearson correlation analyses. A novel score between glucose and lipid metabolism-associated gene expression was calculated. In The Cancer Genome Atlas Liver Hepatocellular Carcinoma dataset, the prognostic power of selected metabolism-associated genes and a novel score was evaluated for external validation. Results: Nine genes related to glycolysis and the HIF-1 signaling pathway showed positive correlations with tumor FDG uptake; 21 genes related to fatty acid metabolism and the PPAR signaling pathway demonstrated negative correlations. Seven potential biomarker genes, PFKFB4 , ALDOA , EGLN3 , EHHADH , GAPDH , HMGCS2 , and ENO2 were identified. A metabolic gene expression balance score according to the dominance between glucose and lipid metabolism demonstrated good prognostic value in HCC. Conclusions: The transcriptomic evidence of this study strongly supports the prognostic power of FDG PET/CT and indicates the potential usefulness of FDG PET/CT imaging biomarkers to select appropriate patients for metabolism-targeted therapy in HCC. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the role of positron emission tomography/computed tomography (PET/CT) in predicting pathologic complete response (pCR) and identify relevant prognostic factors from clinico-imaging-pathologic features of locally advanced esophageal squamous cell carcinoma (eSCC) patients undergoing trimodality therapy. Methods: We evaluated 275 patients with eSCCs of T3-T4aN0M0 and T1-T4aN1-N3M0 who received trimodality therapy. We correlated volume-based PET/CT parameters before and after concurrent chemoradiation therapy with pCR after surgery, clinico-imaging-pathologic features, and patient survival. Results: pCR occurred in 75 (27.3%) of 275 patients, of whom 61 (80.9%) showed 5-year survival. Pre-total lesion glycolysis (pre-TLG, OR = 0.318, 95% CI 0.169 to 0.600), post-metabolic tumor volume (post-MTV, OR = 0.572, 95% CI 0.327 to 0.999), and % decrease of average standardized uptake value (% SUVavg decrease, OR = 2.976, 95% CI = 1.608 to 5.507) were significant predictors for pCR. Among them, best predictor for pCR was pre-TLG with best cutoff value of 205.67 and with AUC value of 0.591. Performance status (HR = 5.171, 95% CI 1.737 to 15.397), pathologic tumor size (HR = 1.645, 95% CI 1.351 to 2.002), pathologic N status (N1, HR = 1.572, 95% CI 1.010 to 2.446; N2, HR = 3.088, 95% CI 1.845 to 5.166), and post-metabolic tumor volume (HR = 1.506, 95% CI 1.033 to 2.195) were significant predictors of overall survival. Conclusion: Pre-TLG, post-MTV, and % SUVavg decrease are predictive of pCR. Additionally, several clinico-imaging-pathologic factors are significant survival predictors in locally advanced eSCC patients undergoing trimodality therapy. [ABSTRACT FROM AUTHOR]

Chronic obstructive pulmonary disease (COPD) has been regarded as a disease of smokers, but the prevalence of non-smoking COPD patients have been reported to be considerable. We investigated differences in clinical characteristics between smoking and non-smoking COPD patients. We used data from the Korea COPD Subgroup Study (KOCOSS) database, which is a multicenter cohort that recruits patients from 54 medical centres in Korea. Comprehensive comparisons of smoking and non-smoking COPD patients were performed based on general characteristics, exacerbations, symptom scores, radiological findings, and lung-function tests. Of the 2477 patients included in the study, 8.1% were non-smokers and 91.9% were smokers. Non-smoking COPD patients were more likely to be female and to have a higher body mass index and lower level of education. Non-smoking COPD patients had more comorbidities, including hypertension, osteoporosis, and gastroesophageal reflux disease, and experienced more respiratory and allergic diseases. No significant differences in exacerbation rates, symptom scores, or exercise capacity scores were observed between the two groups. Smoking COPD patients had more emphysematous lung according to the radiological findings, and non-smoking patients had more tuberculosis-destroyed lung and bronchiectasis. Lung-function testing revealed no significant difference in the forced expiratory capacity in 1 sec between the two groups, but smokers had more rapid lung-function decline in the 5 years of follow-up data. We found differences in general characteristics and radiological findings between smoking and non-smoking COPD patients. No significant differences in exacerbation or symptom scores were observed, but decline in lung function was less steep in non-smoking patients. Supplemental data for this article is available online at https://doi.org/10.1080/15412555.2022.2053088. [ABSTRACT FROM AUTHOR]