Pulmonary Nodule Detection: Comparison of an Ultra Low Dose vs Standard Scan.

Study Overview
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Brief Summary
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Lung cancer screening programs are still discussed in Europe today, and one of the concern is radiation due to iterative CT. The aim of this monocentric, prospective, non randomized study is to compare an ultra low dose chest CT (approaching a two views X ray) versus a standard low dose chest CT for ≥4mm lung nodules detection, and secondary for lung nodule characterization and smoking associated findings (emphysema, bronchial abnormalities and coronary calcifications).

Detailed Description
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An additional Ultra Low Dose CT, approaching 0.2mSv, will be performed in consenting patients referred for non enhanced chest CT in our Revolution CT scanner (GE Healthcare®).The dose delivered with the two acquisitions is still lower than the french diagnostic reference level. Standard CT is interpreted and a report is sent to the referent physician as usual. Then the two acquisitions are read over time by two independent radiologists, blinded over judgment criterias. In case of discordance, an other radiologist will arbitrate. We hope to validate our Ultra low dose chest CT protocol, which is more than 10 times less radiating than a standard low dose CT, as a sensitive tool to detect lung nodules.

Official Title
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Detection of Pulmonary Nodules: Comparison of Ultra-low-dose Chest CT (Approaching a Two Views Chest X-ray Radiation) and Standard Low Dose CT. A Monocentric, Prospective, Non-randomized, Comparative, Open-label Study With Blind Reading of the Judgment Criteria.

Conditions
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Lung Cancer, Smoking, Radiation Exposure

Intervention / Treatment
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* Device: Ultra low dose chest CT
* Device: Low dose chest CT


Participation Criteria
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Eligibility Criteria
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Inclusion criteria : Patients referred for non enhanced chest CT for following indications : lung nodule search or control nodular abnormality on chest X ray statement of COPD or emphysema asbestos exposure nodule localization before radio frequency ablation assessment of disease extent of an extra thoracic cancer (in case of iodinated intravenous contrast agent contraindication) statement before extrathoracic transplantation (in case of iodinated intravenous contrast agent contraindication) Affiliated with the french social security Who signed consent Exclusion criteria : Inability to lie down and still during the examination Inability to hold breath more than 5 seconds Pneumonia in the last 3 months Body mass index more than 35kg/m² exclusion period of another interventionnal study referred for articles L1121-5 to L1121-8 of french public health code Pregnant or breastfeeding women

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Sequential Assignment
Interventional Model Description: Major Patient Addressed for Thoracic CT without Injection of Contrast
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Ultra low dose chest CT<br> | Device: Ultra low dose chest CT<br>* An additional ultra low dose CT row is performed for every subject besides standard diagnostic low dose chest CT.<br>* Other names: Revolution CT (GE Healthcare) 442507CN0, equiped with ASIR V;|
| Active Comparator: Low dose chest CT<br> | Device: Low dose chest CT<br>* standard diagnostic low dose chest CT<br>* Other names: Revolution CT (GE Healthcare);|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ultra low dose CT lung nodule detection sensibility | Detection rate (%) of ≥4mm lung nodules in ultra low dose chest CT versus standard low dose chest CT | 22 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ultra low dose CT diagnostic performances of lung nodule detection | true positives, false positives, true negatives, false negatives, positive predictive value, negative predictive value, specificity, of ≥4mm lung nodules detection within ultra low dose chest CT versus standard low dose chest CT | 22 months | 
| Concordance of ≥4mm lung nodules characteristics between ultra low dose and standard low dose chest CT | comparison of size, density, type (true nodule or intrapulmonary ganglion) of ≥4mm lung nodule between ultra low dose and standard low dose chest CT | 22 months | 
| Ultra low dose CT inter-observer reproducibility | inter observer reproducibility for size, density and type of ≥4mm lung nodule detected in ultra low dose CT | 22 months | 
| Influence of subjects characteristics, nodule location, and nodule size on detection between ultra low dose and standard low dose chest CT | analysis of subjects characteristics (age, gender, body mass index), ≥4mm nodule location, and ≥4 mm nodule size on detection between ultra low dose and standard low dose chest CT | 22 months | 
| Concordance of emphysema characteristics between ultra low dose and standard low dose chest CT | comparison of emphysema detection, type (centrilobular, paraseptal, panlobular, bullous) and distribution between ultra low dose and standard low dose chest CT | 22 months | 
| Concordance of coronary calcification detection and quantification between ultra low dose and standard low dose chest CT | Comparison of Weston scores between ultra low dose and standard low dose chest CT | 22 months | 
| Concordance of bronchial abnormalities evaluation between ultra low dose and standard low dose chest CT | comparison of detection of bronchial thickening or dilatation between ultra low dose and standard low dose chest CT | 22 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Ultra low dose chest CT, lung cancer screening