Étude NpUBD : détection des nodules pulmonaires, comparaison d’une acquisition scanner ultra-basse dose (à une irradiation proche de la radiographie thoracique face et profil) versus basse dose

Abstract

Introduction: Lung cancer screening using computed tomography (CT) is currently being discussed but repeated radiation exposure is a real concern. The aim of npUBD (NCT03305978), a prospective monocentric study, is to show that an ultra-low dose (UBD) CT using recently introduced iterative reconstruction (ASIR-V) is as efficient as a reference low-dose (BD) CT for the detection of ≥4mm uncalcified pulmonary nodules. Methods and analysis: For each patient included in the study (150 planned), a UBD CT is performed in addition to the reference BD CT. This additional UBD CT is reconstructed with 50 and 100% ASIR-V (UBD50; UBD100). The 3 anonymized series are read independently by 2 pairs of radiologists. The detection sensitivity of ≥4mm uncalcified pulmonary nodules with UBD CT versus BD CT is the main judgement criterion. Secondary objectives include concordance of nodules, emphysema and coronary calcifications. Interim results: Among the first 50 patients, 10 were secondarily excluded for the following reasons: ≥6 nodules in at least one lung (n=9) and BMI>35 (n=1). 55 nodules were identified in 26 patients on the reference BD. Mean effective dose is 1.3mSv for UBD and 0.1mSv for BD. The UBD versus BD detection rate is 72.7% (UBD50) and 76.4% (UBD100) (p>0.05), ranging respectively from 50 and 58.3% for ground glass nodules to 78.9 and 81.6% for solid nodules. Conclusion: The radiation dose delivered by UBD is <10% to that of BD CT. The intermediate results show a lower detection rate of ≥4mm pulmonary nodules than expected but need to be confirmed by the final analysis.