Pulmonary emphysema quantification at low dose chest CT using Deep Learning image reconstruction.

PURPOSE: Quantitative analysis of emphysema volume is affected by the radiation dose and the CT reconstruction technique. We aim to evaluate the influence of a commercially available deep learning image reconstruction algorithm (DLIR) on the quantification of pulmonary emphysema in low-dose chest CT. METHODS: We performed a retrospective study of low dose chest CT scans in 54 patients with chronic obstructive pulmonary disease (COPD). Raw data were reconstructed using FBP, iterative reconstruction (ASIR-V 70%) and deep learning based algorithms at high, medium and low-strength (DLIR -H, -M, -L). Filtered FBP images served as reference. Pulmonary emphysema volume (proportion of voxels below -950 UH) was measured on each reconstruction dataset and visually assessed by a chest radiologist. Quantitative image quality was assessed by placing 3 regions of interest in the trachea, in air and in a paraspinal muscle. Signal to noise ratio was also measured. RESULTS: The mean CDTIvol was 2.38 ± 0.68 mGy. Significant differences in emphysema volumes between the filtered FBP reference and ASIR-V, DLIR-H, DLIR-M or DLIR-L were observed, (p < 10-3) for all. A strong correlation between filtered FBP volumes and DLIR-H was reported (r = 0.999, p < 10-4), a 10% overestimation with DLIR-H being observed. Noise was significantly reduced in DLIR-H volumes compared to the other reconstruction methods. Signal to noise ratio was improved when using DLIR-H (p < 10-6). CONCLUSION: There are significant differences regarding emphysema volumes between FBP, iterative reconstruction or deep learning-based DLIR algorithm. DLIR-H shows the closest correlation to filtered FBP while increasing SNR.

Epidemiological impact of lung cancer screening by low dose CT scan in the French Department of the SOMME.

CONTEXT: Lung cancer is the leading cause of cancer death worldwide. In recent years, screening using low-dose CT scan has shown a reduction in lung cancer-related mortality and in all-cause mortality. The DEP KP80 study was implemented in the French department of the Somme with the aim of investigating lung cancer screening in practice. The results of the first round showed a prevalence of 2.7% for lung cancer, with the majority at localized stages (77%). The primary objective of our study was to compare the stage at diagnosis of patients with lung cancer screened as part of DEP KP80 and those who were not screened. The secondary objectives were to describe the epidemiological characteristics of lung cancer in the French department of the Somme for the period in question and to compare survival rates in screened and unscreened patients. METHODS: This retrospective cohort study compared from May 2016 to December 2017 the characteristics of patients with lung cancer screened as part of DEP KP80 and those who were not screened, using data from the Somme Cancer Registry. RESULTS: In total, 644 patients with lung cancer were included (18 in the screened group and 626 in the unscreened group). There was a significant inversion in the stage distribution at diagnosis, with a predominance of metastatic or locally advanced stages (69%) and a minority of early stages (31%) in unscreened patients, and a majority of early stages (77.8%) and a lower proportion of locally advanced or disseminated stages (22.2%) in screened patients (p < 0.01). In the screened group, there was a significant improvement in survival, a higher rate of surgical resection, and a longer time interval between first contact and treatment initiation. CONCLUSION: Lung cancer screening by low-dose CT scan in the French department of the Somme showed an impact on stage at diagnosis, with a majority of early stages in screened patients, allowing for curative treatment with a significant improvement in survival.

Results of Second Round Lung Cancer Screening by Low-Dose CT scan - French Cohort Study (DEP-KP80).

INTRODUCTION: Over the last few years, lung cancer screening by low-dose CT scan has demonstrated a decrease in lung cancer mortality. While this method has been in use since 2013 in the United States of America, no European country has yet implemented a systematic screening program. We hereby report the results from the second round of screening from a French cohort study. PATIENTS AND METHODS: DEP KP80 is a prospective study evaluating lung cancer screening by means of three low-dose computer tomography (CT) scans at 1-year intervals in 1,307 participants, aged 55 to 74 years old, all smokers or former smokers, having quit within the last 15 years, with over 30 pack years. The results of the first round demonstrated it was possible to conduct effective screening in real-life situations. RESULTS: Participation was lower in this second round than in the first (35.3% vs. 73.1%, P < .001). The rate of negative results was significantly higher and that of undetermined results lower than those produced in the first round. Overall, 75% of cancers revealed were Stage 1 and 87.5% benefitted from surgical treatment. The incidence of cancer in the second round was 2.43%. CONCLUSION: As with the first round, the results of this second round confirm the feasibility and efficacy of lung cancer screening. The lower participation rate for this second round is proof of the need to improve awareness among participants and healthcare professionals of the relevance of committing to an annual screening program.

Lung Cancer Screening by Low-Dose CT Scan: Baseline Results of a French Prospective Study.

BACKGROUND: Lung cancer mortality has been found to decrease significantly with low-dose (LD) computed tomographic (CT) screening among current or former smokers. However, such a screening program is not implemented in France. This study assessed the feasibility of a lung cancer screening program using LD CT scan in a French administrative territory. We report here the results of the first screening round. PATIENTS AND METHODS: DEP KP80 was a single-arm prospective study initiated in May 2016. Participants aged 55 to 74 years, current or former smokers of ≥ 30 pack-years, were recruited. An annual LD CT scan was scheduled. Our algorithms considered nodules < 5 mm as negative findings and nodules > 10 mm as positive; for intermediate nodules between 5 and 10 mm, 3-month CT scan with doubling time measurement was recommended. All general practitioners, pulmonologists, and radiologists from the Somme department were solicited to participate. Subjects were selected by general practitioners or pulmonologists who checked the inclusion criteria and prescribed the CT scan. RESULTS: Over a 2.5-year period, 1307 subjects were recruited. Screening was negative in 733 cases (77.2%), positive in 54 (5.7%), and indeterminate in 162 (17.1%). After the 3-month scans, 57 subjects screened positive: 26 patients exhibited 31 lung cancers (67.7% of stage 0 to I), of whom 76.9% underwent surgical resection, and 29 had no cancer (false-positive rate = 3.1%). The prevalence of lung cancer was 2.7%. CONCLUSION: This study demonstrated the feasibility of organized lung cancer screening using LD CT scan within a real-life context in the general population.

Two cases of pneumonitis induced by targeted therapy.

Interstitial pneumonitis is a rare drug adverse effect. We report two cases of cobimetinib-induced and vemurafenib-induced reversible interstitial pneumonitis. Two patients presenting a BRAF-mutated metastatic melanoma were treated with cobimetinib and vemurafenib. After 3 months, they developed severe feverish dyspnea. Thoracic imaging showed a pattern of organizing pneumonia in one case and a pattern of hypersensitivity pneumonitis in the other case. Infectious and cardiogenic causes were eliminated. An improvement was noted after discontinuation of cobimetinib, vemurafenib, and introducing steroids. Treatment was switched to dabrafenib (a BRAF inhibitor) with no recurrence of drug pneumonitis. To the best of our knowledge, it appears that cases of targeted-therapy-induced pneumonitis are predominantly an MEK-inhibitor effect. We, therefore, propose a management strategy of discontinuing targeted therapy, introducing steroid treatment and switching to dabrafenib.