ABSTRACT
The goal of computed tomography (CT) screening is to detect lung cancer at an earlier stage when intervention may be more likely to lead to cure. Toward achieving this goal, the desire is to identify cancers when they are small and before they have developed nodal or distant metastases. CT is inherently limited in detection of early, centrally located airway cancers. Consequently, nearly all screen-detected early-stage cancers will be identified nodular opacities in the parenchyma. As cancer growth requires time, and assuming similar growth rates, a smaller nodular cancer implies it is earlier in development than a larger one. The desire to detect small cancers is made problematic by the potential number of small benign lesions from which the malignant ones require identification. Herein lies the crux of the problem presented to the clinician or researcher evaluating the patient or participant who has been screened. Optimal evaluation of screen-detected lesions identifies cancer with haste and avoids resection of benign lesions.
