Influence of Tumor Cavitation on Assessing the Clinical Benefit of Anti-PD1 or PD-L1 Inhibitors in Advanced Lung Squamous Cell Carcinoma.

PURPOSE: A considerable portion of lung squamous cell cancer (LUSC) displays radiographic signs of cavitation. The cavitation of lesions is not accounted for in the prevailing Evaluation Criteria of Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 or iRECIST in lung cancer. We hypothesized that cavitation might alter response assessment in these patients. PATIENTS AND METHODS: We performed a retrospective radiologic review of 785 patients with stage IV LUSC treated with PD-1/PD-L1 antibody combined with platinum-based doublet chemotherapy. 131 patients exhibited cavitation lesions pre- or after-treatment. Response was assessed by RECIST v1.1 and a modified Evaluation Criteria in Solid Tumors (mRECIST) guidelines in which the longest diameter of any cavity was subtracted from the overall longest diameter of that lesion to measure target lesions. The response rate and PFS and OS between mRECIST and RECIST v1.1 were compared. Survival curves of different response categories in each criterion were prepared using the method of Kaplan-Meier and log-rank tests. Weighted κ statistics were used to assess interobserver reproducibilities and to compare response rates. The chi-square test confirmed the relationship between PD-L1 expression and post-treatment cavitation. RESULTS: Notable cavitation of pulmonary lesions was seen in 16.7% of 785 patients treated with immunotherapy combined with platinum-based chemotherapy. Using the mRECIST for response assessment resulted in a higher response rate than RECIST v1.1 (66% vs. 57%). mRECIST might better identify patients with PFS and OS benefits who have cavitation. The chi-square test revealed a marginally significant difference between PD-L1 expression and tumor cavitation. Interobserver reproducibility of mRECIST for tumor cavitation evaluation was acceptable (the weighted k coefficients for mRECIST criteria was 0.821). CONCLUSION: Cavitation lesions at baseline and after checkpoint treatment are common in LUSC patients. mRECIST records a significantly higher response rate than RECIST for these LUSC patients. Response assessment might be improved by incorporating cavitation into volume assessment for target lesions. These results may inform further modifications to RECIST V1.1 to better reflect efficacy with immunotherapy.

Preoperative CT-based radiomics combined with tumour spread through air spaces can accurately predict early recurrence of stage I lung adenocarcinoma: a multicentre retrospective cohort study.

OBJECTIVE: To develop and validate a prediction model for early recurrence of stage I lung adenocarcinoma (LUAD) that combines radiomics features based on preoperative CT with tumour spread through air spaces (STAS). MATERIALS AND METHODS: The most recent preoperative thin-section chest CT scans and postoperative pathological haematoxylin and eosin-stained sections were retrospectively collected from patients with a postoperative pathological diagnosis of stage I LUAD. Regions of interest were manually segmented, and radiomics features were extracted from the tumour and peritumoral regions extended by 3 voxel units, 6 voxel units, and 12 voxel units, and 2D and 3D deep learning image features were extracted by convolutional neural networks. Then, the RAdiomics Integrated with STAS model (RAISm) was constructed. The performance of RAISm was then evaluated in a development cohort and validation cohort. RESULTS: A total of 226 patients from two medical centres from January 2015 to December 2018 were retrospectively included as the development cohort for the model and were randomly split into a training set (72.6%, n = 164) and a test set (27.4%, n = 62). From June 2019 to December 2019, 51 patients were included in the validation cohort. RAISm had excellent discrimination in predicting the early recurrence of stage I LUAD in the training cohort (AUC = 0.847, 95% CI 0.762-0.932) and validation cohort (AUC = 0.817, 95% CI 0.625-1.000). RAISm outperformed single modality signatures and other combinations of signatures in terms of discrimination and clinical net benefits. CONCLUSION: We pioneered combining preoperative CT-based radiomics with STAS to predict stage I LUAD recurrence postoperatively and confirmed the superior effect of the model in validation cohorts, showing its potential to assist in postoperative treatment strategies.

Preoperative CT-guided localization of pulmonary nodules with low-dose radiation.

Background: Video-assisted thoracoscopic surgery (VATS) has been widely accepted for the treatment of pulmonary nodules. Prior to VATS, pulmonary nodules can be labeled by computed tomography (CT)-guided hook wire localization, but multiple scans are required, which increases the total radiation dose. We aimed to assess the effectiveness and risks of using low-dose radiation CT to locate lung nodules prior to VATS. Methods: This study included 158 patients who underwent VATS resection after CT-guided hook wire localization. Based on the CT tube voltage, patients were split into two groups: the low-voltage group (Group A) received 80 kV, while the high-voltage group (Group B) received 120 kV. The two groups' image quality, radiation exposure, localization success and complication rates were compared. The frequencies of intraoperative complications and the types of lung nodules were also compared between the groups. Results: Successful nodule mapping was obtained in 158 patients. There was no significant difference in age, sex ratio or BMI between the two groups. Subjective imaging quality in both groups met the requirements for location (≥2 points). The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in Group A were lower than those in Group B (P<0.05). Furthermore, the dose length product (DLP) and effective dose (ED) in Group A were lower than those in Group B (P<0.05). Conclusions: Low-dose radiation CT-guided localization is safe and feasible for identifying uncertain pulmonary nodules before VATS, enabling a significant radiation dose reduction while maintaining mapping accuracy and not increasing complication risk.

Artificial Intelligence-Aided Diagnosis Software to Identify Highly Suspicious Pulmonary Nodules.

INTRODUCTION: To evaluate the value of artificial intelligence (AI)-assisted software in the diagnosis of lung nodules using a combination of low-dose computed tomography (LDCT) and high-resolution computed tomography (HRCT). METHOD: A total of 113 patients with pulmonary nodules were screened using LDCT. For nodules with the largest diameters, an HRCT local-target scanning program (combined scanning scheme) and a conventional-dose CT scanning scheme were also performed. Lung nodules were subjectively assessed for image signs and compared by size and malignancy rate measured by AI-assisted software. The nodules were divided into improved visibility and identical visibility groups based on differences in the number of signs identified through the two schemes. RESULTS: The nodule volume and malignancy probability for subsolid nodules significantly differed between the improved and identical visibility groups. For the combined scanning protocol, we observed significant between-group differences in subsolid nodule malignancy rates. CONCLUSION: Under the operation and decision of AI, the combined scanning scheme may be beneficial for screening high-risk populations.

Low kV and Low Concentration Contrast Agent with Iterative Reconstruction of Computed Tomography (CT) Coronary Angiography: A Preliminary Study.

BACKGROUND The aim of this study was to evaluate the image quality and radiation dose of CT coronary angiography (CTCA) with low kV, low concentration contrast agent, and iterative reconstruction. MATERIAL AND METHODS Ninety cases were randomly divided into 3 groups according to contrast agent concentration: group A 270 mg/ml (100 kV), group B 350 mg/ml (120 kV), and group C 370 mg/ml (120 kV), with 30 cases per group. Tube current was 200-250 mAs. Collimator width was 128×0.6 mm. Rotation speed was 0.27 s. The CT value of the left and right coronary arteries and the ascending aortic root was measured. The SNR and CNR of the images were calculated to evaluate the image quality objectively. The CTDI, DLP, and contrast injection were recorded. RESULTS There were no significant differences in sex, age, weight, height, and BMI among the 3 groups. There was no statistically significant difference between left and right coronary artery and ascending aortic root CT value, background noise, SNR, and CNR. Compared to B and C, the ED in group A decreased by about 27.58% and 28.21%, respectively. The total amount of iodine in group A was decreased by about 21.27% and 24.83%, respectively compared with groups B and C. CONCLUSIONS Low kV and low concentration contrast agent combined with iterative reconstruction for CTCA imaging produced image quality consistent with that of conventional CTCA and significantly reduced the dosage of the radiation and injected iodine.

Predictive value of insufficient contrast medium filling in pulmonary veins in patients with acute pulmonary embolism.

This study is to investigate the predictive value of insufficient contrast medium filling (ICMF) in patients with acute pulmonary embolism (PE).A total of 108 PE patients were enrolled and divided into group A and group B according to the presence of ICMF. PE index and ventricul araxial lengths were measured. Heart cavity volumes were examined and right ventricle (RV) to left ventricle (LV) diameter ratio (RV/LV(d)) and volume ratio (RV/LV(V)) and right atrium (RA) to left atrium (LA) volume ratio (RA/LA(V)) were calculated and compared. Group A was further divided into A1 and A2 based upon the pulmonary vein filling degree and each index was compared.There were no significant differences between group A and B in general condition. PE index of group A was higher than that of group B. LA and LV in group A were smaller than that of group B, whereas RA in group A was larger than that of group B. RV/LV(d), RV/LV(V), and RA/LA(V) in group A were significantly larger than that of group B. Embolism index of group A2 was higher than that of groupA1, but without statistical significant difference. LA in group A2 was smaller than that of group A1, whereas RA, RV/LV(d), and RV/LV(V) were larger than that of group A1, all with significant differences.PE increased with serious ICMF in pulmonary veins could be used as an indicator for risk stratification in patients with acute PE.