Alain Tremblay

MDCM

THE GOVERNORS OF THE UNIVERSITY OF CALGARY

Professor of Medicine

NLST (Learn more about this study)

NLST-849

Nov 5, 2021

Modified Lung-RADS classification incorporating nodule risk calculator.

Several approaches have been proposed for interpretation and classification of nodules detected by low-dose CT (LDCT) scan performed for lung cancer screening. Performance characteristics of the system chosen in a screening program affect false-positive and false- negative rates, as well as early recall rates, and therefore the ability of a program to detect cancers early while avoiding costs and harms of investigations for benign lesions.
The ACR Lung Screening Reporting and Data System (Lung-RADS) classification system, which incorporates nodule characteristics (solid, part-solid, and nonsolid) in addition to size, has been widely adopted in the United States. Nodule risk calculators have been used for many years in the clinical setting and can also be applied to the screening environment. The Pan-Canadian Early Detection of Lung Cancer (PanCan) nodule risk calculator was developed and validated specifically in the LDCT screening setting and has performed favorably in retrospective comparisons with other approaches.
Our work and others has suggested that each of these 2 approaches have advantages and shortcomings. For example, Lung-RADS classifies as higher risk many mid-size lung nodules calculated to be of <5% cancer risk while PanCan classifies many ground glass lesions as high risk, even if most are indolent and do not require immediate action. Local data suggest that early recall investigations after a baseline screen could be reduced by 1/3 if a hybrid system incorporating Lung-RADS categories and PanCan calculator without loss of sensitivity for cancer (J Am Coll Radiol 2019 Oct;16(10):1425-1432).