18-fluorine fluorodeoxyglucose positron emission tomography with computerized tomography versus computerized tomography alone for the management of solitary lung nodules with diameters inferior to 1.5 cm

Abstract

Objective: Aim of the study was to establish a noninvasive method for the preoperative characterisation of a pulmonary nodule when biopsy of the small mass is impossible.

Methods: From 1 January 2006 to 31 December 2008, we observed 124 asymptomatic patients with a noncalcified single lung nodule highlighted by computerised tomography (CT) of the thorax. Patients were divided into 2 groups: Group A consisted of 57 patients with lesion diameters between 0.5 cm and 0.99 cm; Group B consisted of 67 patients with lesion diameters between 1.0 cm and 1.5 cm. Fibreoptic bronchoscopy was negative for endobronchial neoformation in all patients. The topographic distribution of the lesions advised against CT-guided transthoracic needle biopsy or video-assisted thoracoscopy. All patients had preoperative 18-fluorine fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) associated with CT of the thorax, which was compared with CT for evaluation of the mass.

Results: Postoperative histological diagnosis revealed 54 primary lung cancers, 47 lung metastases and 23 benign lesions. In Group A the sensitivity of 18F-FDG PET/CT and CT was 95 % and 73 % and the specificity was 72 % and 64 %, respectively ( P = 0.000001 for 18F-FDG PET/CT; P = 0.000177 for CT). In Group B the sensitivity of 18F-FDG PET/CT and CT was 95 % and 97 %, and the specificity was 80 % and 87 %, respectively ( P = 0.000001).

Conclusions: Our study shows that 18F-FDG PET/CT improves the identification and characterisation of potentially malignant pulmonary nodules with a diameter < 1 cm. This technique could be a valid alternative to a surgical approach, currently the main method to investigate indeterminate lung nodules.