Ground-glass Component Research Articles

Diagnostic Accuracy and Safety of Nonsurgical Biopsy for Diagnosing Pulmonary Ground-Glass Opacities: A Systematic Review and Meta-Analysis.

Previous meta-analyses have explored the diagnostic accuracy and safety of computed tomography-guided percutaneous lung biopsy of ground-glass opacities (GGOs). However, no research investigated the role of nonsurgical biopsies (including transbronchial approaches). Additionally, studies reporting the diagnostic accuracy of GGOs with different characteristics are scarce, with no quantitative assessment published to date. We performed a systematic review to explore the diagnostic accuracy and safety of nonsurgical biopsy for diagnosing GGOs, especially those with higher ground-glass components and smaller nodule sizes. A thorough literature search of four databases was performed to compile studies evaluating both or either of the diagnostic accuracy and complications of nonsurgical biopsy for GGOs. A bivariate random-effects model and random-effect model were utilized for data synthesis. The methodological quality of the studies was assessed according to the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Nineteen eligible studies with a total of 1,379 biopsy-sampled lesions were analyzed, of which 1,124 were confirmed to be malignant. Nonsurgical biopsy reported a pooled sensitivity of 0.89, a specificity of 0.99, and a negative predictive value (NPV) of 60.3%. The overall sensitivity, specificity, and NPV of nonsurgical biopsy for diagnosing GGOs according to GGO component were 0.90, 0.99, and 77.2% in pure GGOs; 0.87, 0.99, and 67.2% in GG-predominant lesions; and 0.89, 1.00, and 44.1% in solid-predominant lesions, respectively. Additionally, the diagnostic sensitivity was better in lesions ≥20 mm than in small lesions (0.95 vs. 0.88). Factors that contributed to higher sensitivity were the use of a coaxial needle system and CT fluoroscopy but not the needle gauge. The summary sensitivity of core needle biopsy (CNB) was not significantly higher than fine needle aspiration (FNA) (0.92 vs. 0.84; p = 0.42); however, we found an increased incidence of hemorrhage in CNB compared with FNA (60.9 vs. 14.2%; p = 0.012). Nonsurgical biopsy for diagnosing GGOs shows high sensitivity and specificity with an acceptably low risk of complications. However, negative biopsy results are unreliable in excluding malignancy, necessitating resampling or subsequent follow-up. The applicability of our study is limited due to significant heterogeneity, indirect comparisons, and the paucity of data on bronchoscopic approaches, restricting the generalizability of our findings to patients requiring transbronchial biopsies.

Multi-omics analysis unveils immunosuppressive microenvironment in the occurrence and development of multiple pulmonary lung cancers

Multiple pulmonary lung cancers (MPLCs) are frequently encountered on computed tomography (CT) scanning of chest, yet their intrinsic characteristics associated with genomic features and radiological or pathological textures that may lead to distinct clinical outcomes remain largely unexplored. A total of 27 pulmonary nodules covering different radiological or pathological textures as well as matched adjacent normal tissues and blood samples were collected from patients diagnosed with MPLCs. Whole-exome sequencing (WES) and whole-transcriptome sequencing were performed. The molecular and immune features of MPLCs associated with distinct radiological or pathological textures were comprehensively investigated. Genomics analysis unveiled the distinct branches of pulmonary nodules originating independently within the same individual. EGFR and KRAS mutations were found to be prevalent in MPLCs, exhibiting mutual exclusivity. The group with KRAS mutations exhibited stronger immune signatures compared to the group with EGFR mutations. Additionally, MPLCs exhibited a pronounced immunosuppressive microenvironment, which was particularly distinct when compared with normal tissues. The expression of the FDSCP gene was specifically observed in MPLCs. When categorizing MPLCs based on radiological or pathological characteristics, a progressive increase in mutation accumulation was observed, accompanied by heightened chromatin-level instability as ground-glass opacity component declined or invasive progression occurred. A close association with the immunosuppressive microenvironment was also observed during the progression of pulmonary nodules. Notably, the upregulation of B cell and regulatory T cell marker genes occurred progressively. Immune cell abundance analysis further demonstrated a marked increase in exhausted cells and regulatory T cells during the progression of pulmonary nodules. These results were further validated by independent datasets including nCounter RNA profiling, single-cell RNA sequencing, and spatial transcriptomic datasets. Our study provided a comprehensive representation of the diverse landscape of MPLCs originating within the same individual and emphasized the significant influence of the immunosuppressive microenvironment in the occurrence and development of pulmonary nodules. These findings hold great potential for enhancing the clinical diagnosis and treatment strategies for MPLCs.

Editorial Comment: The Prognostic Importance of a Ground-Glass Component in Lung Cancer.

Editorial Comment: The Prognostic Importance of a Ground-Glass Component in Lung Cancer.

Deep-Learning-Based Predictive Imaging Biomarker Model for EGFR Mutation Status in Non-Small Cell Lung Cancer from CT Imaging.

The authors aimed to develop and validate deep-learning-based radiogenomic (DLR) models and radiomic signatures to predict the EGFR mutation in patients with NSCLC, and to assess the semantic and clinical features that can contribute to detecting EGFR mutations. Using 990 patients from two NSCLC trials, we employed an end-to-end pipeline analyzing CT images without precise segmentation. Two 3D convolutional neural networks segmented lung masses and nodules. The combined radiomics and DLR model achieved an AUC of 0.88 ± 0.03 in predicting EGFR mutation status, outperforming individual models. Semantic features further improved the model's accuracy, with an AUC of 0.88 ± 0.05. CT semantic features that were found to be significantly associated with EGFR mutations were pure solid tumours with no associated ground glass component (p < 0.03), the absence of peripheral emphysema (p < 0.03), the presence of pleural retraction (p = 0.004), the presence of fissure attachment (p = 0.001), the presence of metastatic nodules in both the tumour-containing lobe (p = 0.001) and the non-tumour-containing lobe (p = 0.001), the presence of ipsilateral pleural effusion (p = 0.04), and average enhancement of the tumour mass above 54 HU (p < 0.001). This AI-based radiomics and DLR model demonstrated high accuracy in predicting EGFR mutation, serving as a non-invasive and user-friendly imaging biomarker for EGFR mutation status prediction.

Hierarchical classification of early microscopic lung nodule based on cascade network.

Early-stage lung cancer is typically characterized clinically by the presence of isolated lung nodules. Thousands of cases are examined each year, and one case usually contains numerous lung CT slices. Detecting and classifying early microscopic lung nodules is demanding due to their diminutive dimensions and restricted characterization capabilities. Therefore, a lung nodule classification model that performs well and is sensitive to microscopic lung nodules is needed to accurately classify lung nodules. This paper uses the Resnet34 network as a basic classification model. A new cascade lung nodule classification method is proposed to classify lung nodules into 6 classes instead of the traditional 2 or 4 classes. It can effectively classify six different nodule types including ground-glass and solid nodules, benign and malignant nodules, and nodules with predominantly ground-glass or solid components. In this paper, the traditional multi-classification method and the cascade classification method proposed in this paper were tested using real lung nodule data collected in the clinic. The test results demonstrate that the cascade classification method in this study achieves an accuracy of 80.04, outperforming the conventional multi-classification approach. Different from the existing methods for categorizing the benign and malignant nature of lung nodules, the approach presented in this paper can classify lung nodules into 6 categories more accurately. At the same time, This paper proposes a rapid, precise, and dependable approach for classifying six distinct categories of lung nodules, which increases the accuracy categorization compared with the traditional multivariate categorization method.

Is 18F-fluorodeoxyglucose PET recommended for small lung nodules? CT findings of 18F-fluorodeoxyglucose non-avid lung cancer.

To determine the image characteristics associated with low 18F-FDG (18F-fluorodeoxyglucose) avidity among 8-15 mm solid lung cancer. Patients satisfying the following criteria were included: underwent surgery between January 2014 and December 2019 for lung cancer, presented 8-15 mm nodule without measurable ground glass component on preoperative CT, and underwent 18F-FDG PET before resection. Image characteristics, including air bronchogram, concave shape, pleural attachment, and background emphysema, were evaluated by two board-certified radiologists. The Mann-Whitney U test was used to compare maximum standardized uptake (SUVmax) values from 18F-FDG PET images. The analysis included 235 patients. The SUVmax values of lesions with air bronchogram and concave shape were significantly lower than the SUVmax values of lesions without these features (median: 1.55 vs 2.56 and 1.66 vs 2.45, both P < .001), whereas lesions arising from emphysematous lungs had significantly higher SUVmax values than lesions arising from non-emphysematous lungs (2.90 vs 1.69, P < .001). No significant differences were detected between lesions attached and not attached to pleura. The interobserver agreement was almost perfect for air bronchograms and background emphysema (κ = 0.882 and 0.927, respectively), and 89.7% of lesions with air bronchograms and arising from non-emphysematous lungs showed SUVmax values below 2.5. Among 8-15 mm solid lung cancer, the presence of air bronchograms and concave shape and the absence of background emphysema were associated with low 18F-FDG accumulation. 18F-FDG PET can be misleading in differentiating certain type of small solid lung cancer.

Growth characteristics of early-stage (IA) lung adenocarcinoma and its value in predicting lymph node metastasis

BackgroundWe aim to compare the differences in growth characteristics between part-solid and solid lung adenocarcinoma, and to investigate the value of volume doubling time (VDT) or mass doubling time (MDT) in predicting lymph node (LN) metastasis and preoperative evaluation in patients of early-stage (IA) non-small cell lung cancer (NSCLC).MethodWe reviewed 8,653 cases of surgically resected stage IA lung adenocarcinoma between 2018 and 2022, with two follow-up visits at least 3 months apart, comparing diameter, volume, and mass growth of pSN and SN. VDT and MDT calculations for nodules with a volume change of at least 25%. Univariable or multivariable analysis was used to identify the risk factors. The area under the curve (AUC) for the receiver operating characteristic (ROC) curves was used to evaluate the diagnostic value.ResultsA total of 144 patients were included 114 with solid nodules (SN) and 25 with part-solid nodules (pSN). During the follow-up period, the mean VDTt and MDTt of SN were shorter than those of pSN, 337 vs. 541 days (p = 0.005), 298 vs. 458 days (p = 0.018), respectively. Without considering the ground-glass component, the mean VDTc and MDTc of SN were shorter than the solid component of pSN, 337 vs. 498 days (p = 0.004) and 298 vs. 453 days (p = 0.003), respectively. 27 nodules were clinically and pathologically diagnosed as N1/N2. Logistic regression identified initial diameter (p < 0.001), consolidation increase (p = 0.019), volume increase (p = 0.020), mass increase (p = 0.021), VDTt (p = 0.002), and MDTt (p = 0.004) were independent factors for LN metastasis. The ROC curves showed that the AUC for VDTt was 0.860 (95% CI, 0.778–0.943; p < 0.001) and for MDTt was 0.848 (95% CI, 0.759–0.936; p < 0.001).ConclusionsOur study showed significant differences in the growth characteristics of pSN and SN, and the application of VDT and MDT could be a valid predictor LN metastasis in patients with early-stage NSCLC.

Clinical characteristics and progression of pre-/minimally invasive lung adenocarcinoma harboring ALK or RET rearrangements: a retrospective cohort study.

Patients harboring anaplastic lymphoma kinase (ALK) or rearranged during transfection (RET) rearrangements are usually diagnosed at a relatively late stage with nodal and distant metastasis, and rapid progression course of ALK/RET fusion-positive lung cancer were well-known. However, clinical characteristics and course of pre-/minimally invasive lung adenocarcinoma harboring ALK or RET fusions are poorly described. Identifying patients with gene fusions at early stage may offer surgical options that could cure those patients. We retrospectively included patients with surgically resected pre-/minimally invasive lung adenocarcinomas harboring epidermal growth factor receptor (EGFR) mutations or ALK/RET rearrangements, and further compared the patient clinical characteristics, nodule natural course, and survival outcomes. Radiological characteristics including ground-glass component, cystic airspace, pleural attachment, etc. were specially assessed for this study. EGFR (exons 18-22) was detected by Sanger sequencing and quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the ALK/RET rearrangements. Lung cancer-specific survival (LCSS), relapse-free survival (RFS), and overall survival (OS) were all evaluated. Of 238 patients with pre-/minimally invasive lung adenocarcinomas, 226 patients had EGFR mutations, 7 patients had ALK fusions, and 5 patients had RET fusions. Average age at surgery was 45.3 years for ALK/RET-positive group and 52.6 years for EGFR-positive group (P=0.049). Radiologically, among the 12 patients with ALK/RET fusions, the majority of lesions (10/12) manifested as mixed ground-glass opacities (mGGOs), which was significantly more prevalent when compared with patients with EGFR mutations (83.4% vs. 24.3%, P<0.001). Moreover, a substantial proportion of cystic airspace was found in ALK/RET-positive group but not in EGFR-positive group (66.7% vs. 14.2%, P<0.001). Among four patients with ALK/RET fusions undergoing surveillance over 1 year before surgery, two of them developed rapid radiologic progression. The 5-year LCSS and RFS were 100%, 100% for ALK/RET-positive group, and 100%, 100% for EGFR-positive group, respectively. ALK/RET-positive pre-/minimally invasive lung adenocarcinomas were mostly characterized as mGGOs with cystic airspace developing rapid nodule progression, and no recurrence occurred during long-term follow-up after resection. This provides insights into proper curative surgery timing in the management of patients with gene fusions. However, these findings must be treated with caution and validated in future multi-center studies with larger sample size.

Spatial downregulation of CD74 signatures may drive invasive component development in part-solid lung adenocarcinoma

Pulmonary nodules with part-solid imaging features manifest during the progression from preinvasive to invasive lung adenocarcinoma. To define the spatial composition and evolutionary trajectories of early-stage lung adenocarcinoma, we combined spatial transcriptomics (ST) and pathological annotations from 20 part-solid nodules (PSNs), four of which were matched with single-cell RNA sequencing. Two malignant cell populations (MC1 and MC2) were identified, and a linear evolutionary relationship was observed. Compared to MC2, the pre-existing malignant MC1 exhibited a lower metastatic signature, corresponding to the preinvasive component (lepidic) on pathology and the ground glass component on PSN imaging. Higher immune infiltration was observed among MC1 regions in ST profiles, and further analysis revealed that macrophages may be involved in this process through the CD74 axis. This work provides deeper insights into the evolutionary process and spatial immune cell composition behind PSNs and highlights the mechanisms of immune escape behind this adenocarcinoma trajectory.

Pulmonary MRI with ultra-short TE using single- and dual-echo methods: comparison of capability for quantitative differentiation of non- or minimally invasive adenocarcinomas from other lung cancers with that of standard-dose thin-section CT.

The purpose of this study was thus to compare capabilities for quantitative differentiation of non- and minimally invasive adenocarcinomas from other of pulmonary MRIs with ultra-short TE (UTE) obtained with single- and dual-echo techniques (UTE-MRISingle and UTE-MRIDual) and thin-section CT for stage IA lung cancer patients. Ninety pathologically diagnosed stage IA lung cancer patients who underwent thin-section standard-dose CT, UTE-MRISingle, and UTE-MRIDual, surgical treatment and pathological examinations were included in this retrospective study. The largest dimension (Dlong), solid portion (solid Dlong), and consolidation/tumor (C/T) ratio of each nodule were assessed. Two-tailed Student's t-tests were performed to compare all indexes obtained with each method between non- and minimally invasive adenocarcinomas and other lung cancers. Receiver operating characteristic (ROC)-based positive tests were performed to determine all feasible threshold values for distinguishing non- or minimally invasive adenocarcinoma (MIA) from other lung cancers. Sensitivity, specificity, and accuracy were then compared by means of McNemar's test. Each index showed significant differences between the two groups (p < 0.0001). Specificities and accuracies of solid Dlong for UTE-MRIDual2nd echo and CTMediastinal were significantly higher than those of solid Dlong for UTE-MRISingle and UTE-MRIDual1st echo and all C/T ratios except CTMediastinal (p < 0.05). Moreover, the specificities and accuracies of solid Dlong and C/T ratio were significantly higher than those of Dlong for each method (p < 0.05). Pulmonary MRI with UTE is considered at least as valuable as thin-section CT for quantitative differentiation of non- and minimally invasive adenocarcinomas from other stage IA lung cancers. Pulmonary MRI with UTE's capability for quantitative differentiation of non- and minimally invasive adenocarcinomas from other lung cancers in stage IA lung cancer patients is equal or superior to that of thin-section CT. • Correlations were excellent for pathologically examined nodules with the largest dimensions (Dlong) and a solid component (solid Dlong) for all indexes (0.95 ≤ r ≤ 0.99, p < 0.0001). • Pathologically examined Dlong and solid Dlong obtained with all methods showed significant differences between non- and minimally invasive adenocarcinomas and other lung cancers (p < 0.0001). • Solid tumor components are most accurately measured by UTE-MRIDual2nd echo and CTMediastinal, whereas the ground-glass component is imaged by UTE-MRIDual1st echo and CTlung with high accuracy. UTE-MRIDual predicts tumor invasiveness with 100% sensitivity and 87.5% specificity at a C/T threshold of 0.5.

Quantitative evaluation of density variability in the lesion-lung boundary zone to differentiate pulmonary subsolid nodules.

Transition of the CT values from nodule to peripheral normal lung is related to pathological changes and may be a potential indicator for differential diagnosis. This study investigated the significance of the standard deviation (SD) values in the lesion-lung boundary zone when differentiating between benign and neoplastic subsolid nodules (SSNs). From January 2012 to July 2021, a total of 229 neoplastic and 84 benign SSNs confirmed by pathological examination were retrospectively and nonconsecutively enrolled in this study. The diagnostic study was not registered with a clinical trial platform, and the study protocol was not published. Computed tomography (CT) values of the ground-glass component (CT1), adjacent normal lung tissue (CT2), and lesion-lung boundary zone (CT3) were measured consecutively. The SD of CT3 was recorded to assess density variability. The CT1, CT2, CT3, and SD values were compared between benign and neoplastic SSNs. No significant differences in CT1 and CT2 were observed between benign and neoplastic SSNs (each P value >0.05). CT3 (-736.1±51.0 vs. -792.6±73.9; P<0.001) and its SD (135.6±29.6 vs. 83.6±20.6; P<0.001) in neoplastic SSNs were significantly higher than those in benign SSNs. Moreover, the SD increased with the invasiveness degree of neoplastic SSNs (r=0.657; P<0.001). The receiver operating characteristic (ROC) curve revealed that the area under the curve was 0.927 (95% CI: 0.896-0.959) when using the SD (cutoff value =106.98) as a factor to distinguish SSNs, which increased to 0.966 (95% CI: 0.934-0.985) when including nodules with a CT1 of ≥-715 Hounsfield units (HU) only (cutoff of SD 109.9, sensitivity 0.930, and specificity 0.914). The SD as an objective index is valuable for differentiating SSNs, especially for those with a CT1 of ≥-715 HU, which have a higher possibility of neoplasm if the SD is >109.9.

Prospective Radiologic-Pathologic Correlation of Macroscopic Volume and Microscopic Extension of Nonsolid Lung Nodules on Thin-section CT Images for Sublobar Resection and Stereotactic Radiotherapy Planning

IntroductionThe objective of this study was to determine whether computed tomography (CT) could be a useful tool for nonsolid lung nodule (NSN) treatment planning, surgery or stereotactic body radiation therapy (SBRT), by assessing the macroscopic and microscopic extension of these nodules. MethodsThe study prospectively included 23 patients undergoing anatomic resection at the Foch Hospital in 2020/2021 for NSN with a ground-glass component of more than 50%. Firstly, for each patient, both the macroscopic dimensions of the NSN were assessed on CT and during pathologic analysis. Secondly, the microscopic extension was assessed during pathologic examination. Wilcoxon sign rank tests were used to compare these dimensions. Spearman correlation test and Bland-Altman analysis were used to evaluate the agreement between radiological and pathologic measurements. ResultsOn CT, the median largest diameter and volume of NSN were 21 mm and 3780 cc, while on pathologic analysis, they were 15 mm and 1800 cc, respectively. Therefore, the largest diameter and volume of the NSN were significantly higher on CT than on pathological analysis. For microscopic extension, the median largest diameter and volume of NSN were 17 mm and 2040 cc, respectively. No significant difference was observed between the macroscopic size and the microscopic extension assessed during pathologic analysis. Moreover, correlation analysis and Bland-Altman plots showed that radiological and pathologic measurements could provide equivalent precision. ConclusionOur study showed that CT did not underestimate the macroscopic size and microscopic extension of NSN and confirmed that CT can be used for NSN treatment planning.

MA04.04 The Ground-Glass Component Status Combined with the Clinical T Descriptor Predicts Prognosis and Genomic Alterations in NSCLC

This single-institution retrospective study investigated whether adding the ground-glass component status from high-resolution computed tomography (HRCT) to the T descriptor of the TNM classification serves as a better predictive factor for prognosis in non-small cell lung cancer (NSCLC). In addition, we asked whether the ground-glass component status is related to genetic markers of the cancer.

Single-Cell RNA Sequencing Unravels Distinct Tumor Microenvironment of Different Components of Lung Adenocarcinoma Featured as Mixed Ground-Glass Opacity.

Lung adenocarcinoma featured as mixed ground-glass opacity (mGGO) doubled its volume half of the time in comparison with that featured as pure ground-glass opacity (pGGO). The mechanisms underlying the heterogeneous appearance of mGGO remain elusive. In this study, we macro-dissected the solid (S) components and ground-glass (GG) components of mGGO and performed single-cell sequencing analyses of six paired components from three mGGO patients. A total of 19,391 single-cell profiles were taken into analysis, and the data of each patient were analyzed independently to obtain a common alteration. Cancer cells and macrophages were the dominant cell types in the S and GG components, respectively. Cancer cells in the S components, which showed relatively malignant phenotypes, were likely to originate from both the GG and S components and monitor the surrounding tumor microenvironment (TME) through an intricate cell interaction network. SPP1 hi macrophages were enriched in the S components and showed increased activity of chemoattraction, while macrophages in the GG components displayed an active antimicrobial process with a higher stress-induced state. In addition, the CD47–SIRPA axis was demonstrated to be critical in the maintenance of the GG components. Taken together, our study unraveled the alterations of cell components and transcriptomic features between different components in mGGOs.

The prognostic impact of the ground-glass opacity component in nearly pure-solid stage IA non-small-cell lung cancer.

The aim of this study was to assess the clinical effects of a small ground-glass opacity (GGO) component of a radiologically nearly pure-solid tumour on tumour aggressiveness in patients with clinical stage IA non-small-cell lung cancer (NSCLC). Data of 988 patients with clinical stage IA NSCLC who had a consolidation-to-tumour ratio of ≥0.75 on high-resolution computed tomography were retrospectively analysed. The cumulative incidence of recurrence (CIR) was compared between patients with GGO (nearly pure-solid, n = 297) and those without GGO (pure-solid, n = 691). In patients with clinical T1mi + T1a and T1b, the CIR was significantly higher in the pure-solid group than in the nearly pure-solid group (5-year CIR, 15.2% and 19.3% vs 0% and 6.4%; P < 0.001); however, this was not the case for patients with clinical T1c (5-year CIR, 23.1% vs 26.5%; P = 0.580). In the multivariable analysis, pure-solid tumours were independently associated with a higher CIR than nearly pure-solid tumours in patients with clinical T1mi + T1a + T1b (solid tumour size ≤2 cm; subdistribution hazard ratio, 3.25; 95% confidence interval, 1.59-6.63; P = 0.001) but not in those with clinical T1c tumours (2-3 cm; subdistribution hazard ratio, 0.67; 95% confidence interval, 0.39-1.13; P = 0.130). Nearly pure-solid tumours with a small GGO component influence tumour aggressiveness based on solid tumour size, with a threshold of 2 cm in patients with clinical stage IA NSCLC. For tumours sized 2-3 cm, nearly pure-solid tumours had a similar tumour aggressiveness as pure-solid tumours.

Application Value of Spectral CT Imaging in Quantitative Analysis of Early Lung Adenocarcinoma.

Objective To investigate the clinical value of gemstone energy spectral CT imaging for the quantitative analysis of early lung adenocarcinoma. Methods 76 cases of pulmonary ground-glass nodules pathologically confirmed as precancerous lesion and early lung cancer (including pure ground-glass nodules in 46 cases and mixed ground-glass nodules in 30 cases) underwent chest CT scan first and then underwent contrast-enhanced gemstone energy spectral CT to get arterial phase images, venous phase images, and delayed phase images. All the lesions were set the region of interest (ROI). Cases of the pure ground-glass nodule (pGGN) were measured at the maximum level of lesions, cases of the mixed ground-glass nodule (mGGN) were measured in two areas of ground-glass and solid components, CT value and iodine concentrations of lesions in three-phase scanning were separately measured, and at the same time, iodine concentrations of the thoracic aorta were also measured. The normalized iodine concentrations (NICs) were calculated, that is, the ratio of iodine concentrations of lesions and the thoracic aorta. CT values of lesions were also measured at each stage of 70 keV. All the quantitative data were expressed by the mean ± standard deviation, and paired t-test was used for pairwise comparison. Results In 76 cases, in the spectral CT imaging mode, the NIC value of solid components of the GGN was 0.33 ± 0.16 in the arterial phase (AP), 0.52 ± 0.25 in the venous phase (VP), and 0.58 ± 0.34 in the delayed phase (DP). There were significant differences of P values of NICs between each two phases in both solid component cases and the ground-glass component cases in AP/VP, VP/DP, and AP/DP (P < 0.05); there were no statistically significant P values of CT values between each two phases in three-period enhanced CT in both the solid component cases and the ground-glass component cases in AP/VP, VP/DP, and AP/DP (P > 0.05). Conclusion Gemstone energy spectral CT with quantitative imaging can dynamically reflect the enhancement features of the pulmonary GGN.

Research Progress in 3D-reconstruction Based Imaging Analysis in Partial Solid Pulmonary Nodule

中国肺癌的发病率和死亡率居所有恶性肿瘤之首，随着高分辨率计算机断层扫描（computed tomography, CT）在临床的普及，胸部CT已成为临床筛查早期肺癌、降低肺癌死亡率的重要手段。早期肺腺癌的影像学常表现为含有磨玻璃成分的部分实性结节。随着影像学的发展，部分实性结节的影像学表现与其预后的关系越来越受关注。同时随着三维重建技术的发展，提高了临床医师对该类结节诊断治疗的精确性。本文聚焦于部分实性结节的传统影像学分析和基于三维重建的影像学分析，对两者的利弊作一系统阐述。

Single-cell RNA sequencing reveals the multi-cellular ecosystem in different radiological components of pulmonary part-solid nodules.

BackgroundEarly‐stage lung adenocarcinoma that radiologically manifests as part‐solid nodules, consisting of both ground‐glass and solid components, has distinctive growth patterns and prognosis. The characteristics of the tumour microenvironment and transcriptional features of the malignant cells of different radiological phenotypes remain poorly understood.MethodsTwelve treatment‐naive patients with radiological part‐solid nodules were enrolled. After frozen pathology was confirmed as lung adenocarcinoma, two regions (ground‐glass and solid) from each of the 12 part‐solid nodules and 5 normal lung tissues from 5 of the12 patients were subjected to single‐cell sequencing by 10x Genomics. We used Seurat v3.1.5 for data integration and analysis.ResultsWe comprehensively dissected the multicellular ecosystem of the ground‐glass and solid components of part‐solid nodules at the single‐cell resolution. In tumours, these components had comparable proportions of malignant cells. However, the angiogenesis, epithelial‐to‐mesenchymal transition, KRAS, p53, and cell‐cycle signalling pathways were significantly up‐regulated in malignant cells within solid components compared to those within ground‐glass components. For the tumour microenvironment, the relative abundance of myeloid and NK cells tended to be higher in solid components than in ground‐glass components. Slight subtype composition differences existed between the ground‐glass and solid components. The T/NK cell subsets’ cytotoxic function and the macrophages’ pro‐inflammation function were suppressed in solid components. Moreover, pericytes in solid components had a stronger communication related to angiogenesis promotion with endothelial cells and tumour cells.ConclusionThe cellular landscape of ground‐glass components is significantly different from that of normal tissue and similar to that of solid components. However, transcriptional differences exist in the vital signalling pathways of malignant and immune cells within these components.

Clinical significance of epidermal growth factor receptor mutations in resected stage IA non-small cell lung cancer

Background: Epidermal growth factor receptor (EGFR) gene mutation is a known predictor of the response to EGFR tyrosine kinase inhibitors. However, detecting EGFR mutations is a potential challenge because of the ground-glass opacity component, and its prognostic value for stage IA lung adenocarcinoma remains controversial. This study aimed to investigate the associations between EGFR mutation status, clinicopathological characteristics, and prognosis in surgically resected stage IA non-small cell lung cancer (NSCLC). Materials and Methods: We retrospectively examined the data of patients who underwent surgical resection for lung cancer between 2004 and 2014. The clinical data, imaging characteristics of nodules, surgical approaches, and outcomes were analyzed. Results: A total of 429 patients (female, n = 303; male, n = 126) with surgically resected stage IA NSCLC were analyzed and 343 were nonsmokers. The EGFR mutation rate was 48.3% (n = 207). Of the patients, 192 (44.8%) had stage IA1, 165 (38.5%) had stage IA2, and 72 (16.8%) had stage IA3 NSCLC. In the analysis of the correlations between clinicopathological features and EGFR status, older age (P = 0.032), nonsmoking history (P = 0.039), and pathological stage (P < 0.05) were related to EGFR mutation. Patients with stage IA2 NSCLC had a higher positive expression of EGFR than patients with stages IA1 and IA3. The 5-year overall survival rates and disease-free survival rates were better in the EGFR mutation group; however, the difference was not statistically significant. Conclusion: EGFR mutations are common in older and nonsmoking patients with stage IA NSCLC. Further separate analyses of EGFR gene mutations and pathological stage could improve the diagnostic performance and predict patients with unavailable EGFR gene testing who may benefit from targeted drug treatment.

Clinical significance of part-solid lung cancer in the eighth edition TNM staging system.

The ground-glass component of part-solid tumour (PST) was eliminated as a clinical T (cT) descriptor in the eighth edition of the tumour, node and metastasis (TNM) staging system. We aimed to validate the new cT descriptor and investigate the prognostic impact of PST in the new staging system. Non-small-cell lung cancer (NSCLC) patients (n = 1061) who underwent lung resection and were available for the assessment of thin-section computed tomography images were retrospectively reviewed. Tumours with a solid component (SC) size-to-whole tumour size (STR) ratio of 0, those with 0 < STR < 1 and those with an STR of 1 were defined as pure ground-glass tumours, PSTs and solid tumours (STs), respectively. Tumours with an SC diameter of >30 mm were less frequently observed among PSTs than among STs (4.83% vs 32.6%, P < 0.001). The postoperative 5-year survival of NSCLC patients with ground-glass tumour, PST and ST was 97.6%, 89.0% and 76.3%, respectively. In the survival analysis of patients with an SC diameter ≤30 mm, significant differences were observed among PST and ST (5-year survival, 90.7% vs 74.6%, P < 0.001). The multivariable analysis showed that age <70 years old, female sex, procedures with a lobectomy or more, SC size, pN0 disease and PST were independent predictors of a better survival among all PST and ST patients. Among patients with cT1 tumours, those with PST showed a significantly better survival than did those with ST. Small-sized PST tumours may not be suitable for the new cT descriptor.