Conventional CT and PET/CT imaging in the evaluation and management of subsolid pulmonary nodules: an overview of the literature and author recommendations

Abstract

Subsolid pulmonary nodules (SSNs) are frequent findings on CT scans, and their reported prevalence ranges between 9 and 20% in the literature. The management of SSNs requires specific knowledge. In this review, we report the standard imaging approach and the potential role of positron emission tomography/computed tomography (PET/CT) in the detection of pulmonary SSNs, to help clinicians by providing evidence-based recommendations. The classification of the basic histology, nomenclature, and behaviours of the different lesions is described, with the typical imaging patterns and main recommendations for their management when detected on CT imaging. A comprehensive review of the literature has been performed to determine the potential role of 18F-fluorodeoxyglucose (18F-FDG) PET/CT in the evaluation of SSNs. Finally, we describe the synergy of CT and 18F-FDG PET in the evaluation and management of SSNs. We hypothesise that in cases of 18F-FDG-positive findings, it would be worth considering pre-emptive local treatment with ablation, radiotherapy, or surgical resection. New prospective studies with greater homogeneity of data acquisition, including imaging time points, would be beneficial when reappraising the role of 18F-FDG PET/CT following new technical developments.