Mediastinal Lymphadenopathy in the National Lung Screening Trial (NLST) Is Associated with Interval Lung Cancer.

Background There are currently no evidence-based guidelines for the management of enlarged mediastinal lymph nodes found on lung cancer screening (LCS) CT scans. Purpose To assess the frequency and clinical significance of enlarged mediastinal lymph nodes on the initial LCS CT scans in National Lung Screening Trial (NLST) participants. Materials and Methods A retrospective review of the NLST database identified all CT trial participants with at least one enlarged (≥1.0 cm) mediastinal lymph node identified by site readers on initial CT scans. Each study was reviewed independently by two thoracic radiologists to measure the two largest nodes and to record morphologic characteristics. Scans with extensively calcified mediastinal lymph nodes or nodes measuring less than 1 cm were excluded. Frequency and time to lung cancer diagnosis, lung cancer stage, and histologic findings were compared between NLST participants with and without lymphadenopathy. Results Of the 26 722 NLST participants, 422 (1.6%) had enlarged noncalcified mediastinal lymph nodes on the initial LCS CT scan. Mediastinal lymphadenopathy was associated with an increase in lung cancer cases (72 of 422 participants [17.1%; 95% CI: 13.6, 21.0] vs 1017 of 26 300 [3.9%; 95% CI: 3.6, 4.1]; P < .001), earlier diagnosis (restricted mean survival time ± standard error, 2285 days ± 44 vs 2611 days ± 2; P < .001), the presence of lung nodules (P < .001), advanced stage at presentation (22 of 72 participants [31%] with cancer at stage IIIA vs 410 of 1017 [40.3%] at stage IA; P < .001), and increased mortality (P < .001). The majority of participants with lung cancers in the LCS group with mediastinal lymphadenopathy were detected at initial LCS CT (50 of 422 participants [11.8%; 95% CI: 8.9, 15.3] vs T1-T7, 22 of 422 [5.3%; 95% CI: 3.3, 7.8]; P < .001). There was no association between mediastinal lymphadenopathy and lung cancer histologic findings, CT appearance, or location of lung nodules (P > .05 based on unadjusted pairwise association analyses). Conclusion Noncalcified mediastinal lymphadenopathy in the low-dose lung cancer screening study sample was associated with an increase in lung cancer, an earlier diagnosis, more advanced-stage disease, and increased mortality. More aggressive treatment of these patients appears warranted. © RSNA, 2021 Online supplemental material is available for this article. See also the editorials by McLoud and by Mascalchi and Zompatori in this issue.

Complications of Lung Transplantation: Update on Imaging Manifestations and Management.

As lung transplantation has become the most effective definitive treatment option for end-stage chronic respiratory diseases, yearly rates of this surgery have been steadily increasing. Despite improvement in surgical techniques and medical management of transplant recipients, complications from lung transplantation are a major cause of morbidity and mortality. Some of these complications can be classified on the basis of the time they typically occur after lung transplantation, while others may occur at any time. Imaging studies, in conjunction with clinical and laboratory evaluation, are key components in diagnosing and monitoring these conditions. Therefore, radiologists play a critical role in recognizing and communicating findings suggestive of lung transplantation complications. A description of imaging features of the most common lung transplantation complications, including surgical, medical, immunologic, and infectious complications, as well as an update on their management, will be reviewed here. Keywords: Pulmonary, Thorax, Surgery, Transplantation Supplemental material is available for this article. © RSNA, 2021.

Kaposi sarcoma after bilateral lung transplantation.

We describe radiologic findings in 2 patients and 18-fluoro-deoxy-glucose positron emission tomography/computed tomography findings in 1 patient who developed Kaposi sarcoma of the lung after bilateral lung transplantation. These findings included lung nodules, mediastinal or hilar lymphadenopathy, and pleural fluid.

Prognostic value of computed tomography texture features in non-small cell lung cancers treated with definitive concomitant chemoradiotherapy.

OBJECTIVES: The aim of this study was to investigate whether the computed tomography (CT) texture features of primary tumors are associated with the overall survival (OS) of non-small cell lung cancer (NSCLC) patients undergoing definitive concomitant chemoradiotherapy (CCRT). MATERIALS AND METHODS: In this retrospective study, 98 patients (83 men and 15 women; mean age, 61.9 ± 8.0 years) with unresectable NSCLCs (stage IIIA, 45; stage IIIB, 53) underwent definitive CCRT at our institution from January 2006 to December 2011. Patients were followed up for 3 years or until death. The CT texture parameters of primary tumors were extracted from contrast-enhanced CT images taken before CCRT using an in-house software program. Each texture parameter was dichotomized based on their optimal cutoff values obtained from receiver operating characteristics curve analysis. Three-year OS was compared between the dichotomized subgroups using Kaplan-Meier analysis and the log-rank test. Multivariate Cox regression analysis was performed to determine significant prognostic factors. RESULTS: The 3-year cumulative survival rate was 0.51. The mean 3-year OS was 24.0 months (95% confidence interval, 21.5-26.6 months). There were no significant differences in 3-year OS according to tumor stage or histologic subtypes. However, entropy (P = 0.030), skewness (P = 0.021), and mean attenuation (P = 0.030) were shown to be significantly associated with 3-year OS. Multivariate Cox regression analysis revealed that higher entropy (adjusted hazard ratio [HR],2.31; P = 0.040), higher skewness (adjusted HR,1.92; P = 0.046), and higher mean attenuation (adjusted HR,1.93; P = 0.028) were independent predictors of decreased 3-year OS. CONCLUSIONS: Computed tomography texture features have the potential to be used as prognostic biomarkers in unresectable NSCLC patients undergoing definitive CCRT.

Persistent Pure Ground-Glass Nodules Larger Than 5 mm: Differentiation of Invasive Pulmonary Adenocarcinomas From Preinvasive Lesions or Minimally Invasive Adenocarcinomas Using Texture Analysis.

OBJECTIVE: To evaluate the differentiating potentials of computed tomography texture analysis for invasive pulmonary adenocarcinomas (IPAs) from their preinvasive lesions or minimally invasive adenocarcinomas (MIAs) manifesting as persistent pure ground-glass nodules (PGGNs) larger than 5 mm. MATERIALS AND METHODS: This institutional review board-approved retrospective study included 63 patients (23 men and 40 women) with 66 PGGNs larger than 5 mm on unenhanced computed tomography from 2005 to 2013. All PGGNs were pathologically confirmed and categorized into 2 groups [IPAs (n = 11) vs preinvasive lesions (n = 41)/MIAs (n = 14)]. Each PGGN was segmented manually, and their texture features were quantitatively extracted. To identify significant differentiating factors of IPAs from preinvasive lesions/MIAs, multivariate logistic regression and C-statistic analyses were performed. RESULTS: Between IPAs and preinvasive lesions/MIAs, nodule size, volume, mass, entropy, effective diameter, and surface area were significantly different (P < 0.05), and homogeneity and gray level co-occurrence matrix inverse difference moment showed marginal significance (P < 0.10). Subsequent multivariate analysis revealed larger nodule mass [adjusted odds ratio (OR), 11.92], higher entropy (adjusted OR, 35.12), and lower homogeneity (adjusted OR, 0.278 × 10) as independent differentiating factors of IPAs. Subgroup analysis showed that larger nodule mass, higher entropy, and lower homogeneity were also significant differentiating variables of IPAs in nodules of diameter 10 mm or larger. A multiple logistic regression model using these features showed excellent [area under the curve (AUC), 0.962] and significantly higher differentiating performance compared to nodule size (AUC, 0.712) or mass (AUC, 0.788) alone. CONCLUSION: Computed tomography texture features such as higher entropy and lower homogeneity were significant differentiating factors of IPAs presenting as PGGNs larger than 5 mm and have potentials to enhance the differentiating performance.