The efficacy of positron emission tomography‑CT in simultaneously detected nodules in patients with lung cancer

Abstract

BACKGROUND: The aim of this study is to evaluate the efficacy of positron emissiontomography‑computed tomography (PET‑CT) in the diagnosis of ≤1 cm nodules detected duringlung cancer diagnosis.MATERIALS AND METHODS: Patients with pulmonary parenchymal nodules ≤1 cm during thediagnosis of lung cancer between January 2014 and December 2016 were included in the study.The radiologic (size, location, shape, and contour properties) and radiometabolic (presence offluoro 2‑deoxyglucose [FDG] uptake in the nodule, presence and number of PET‑CT mediastinallymphadenopathy [LAP] uptake, mediastinal LAP maximum standard uptake value [SUVmax],presence and number of PET‑CT extrapulmonary metastasis) features of the nodules were recorded.Nodules that were followed for at least 6 months and unchanged in size were considered benign,and those that increased or decreased in size or completely regressed were considered malignant.RESULTS: Of a total of 167 patients with lung cancer, 116 (69.4%) had no nodules and 51 (30.5%)had nodules. Of the 51 patients with nodules, 27 (53%) had benign and 24 (47%) had malignantnodules. Compared with patients with benign nodules, the FDG uptake rate, SUVmax values,mediastinal LAP uptake in PET‑CT, SUVmax value of the mediastinal LAP with uptake, the numberof mediastinal LAPs with uptake, and reported the presence and number of extrapulmonary distantorgan metastases in PET‑CT were statistically significantly higher in malignant nodules (P < 0.05).Moreover, FDG uptake of the nodule in PET‑CT and the presence of mediastinal LAP uptake inPET‑CT were independent predictors of malignancy of the nodules (P < 0.05).CONCLUSION: PET‑CT parameters other than SUVmax can be used to interpret accompanyingnodules smaller than 1 cm in patients with lung cancer.