The solitary pulmonary nodule--is it malignant or benign? Diagnostic performance of Tc-depreotide SPECT.
BACKGROUND
The diagnosis of malignancy may be difficult to establish in solitary pulmonary nodules (SPNs).


OBJECTIVE
It was the aim of this study to assess diagnostic performances of technetium-99m ((99m)Tc)-depreotide in differentiating benign from malignant SPNs and compare its diagnostic accuracy with fluor-18-fluoro-deoxyglucose positron emission tomography (FDG-PET) in a subgroup of patients.


METHODS
One hundred and eighteen patients presenting with an SPN < or =3 cm suspected of malignancy on CT were included in a prospective, open-label, European multicentre trial. Single photon emission computed tomography (SPECT) images were acquired 1.1-4.5 h after injection of 459-770 MBq of (99m)Tc-depreotide. A subset of 29 patients also underwent FDG-PET imaging. Images were interpreted blindly and correlated with histopathology.


RESULTS
(99m)Tc-depreotide was positive in 65 of 73 patients with a malignant lesion and negative in 30 of 45 patients with a benign lesion, resulting in a sensitivity, specificity and diagnostic accuracy of 89, 67 and 81%, respectively. In 40 patients with SPN < or =1.5 cm, diagnostic accuracy was 88, sensitivity 75 and specificity 96%. In the subset of 29 patients who underwent both (99m)Tc-depreotide SPECT and FDG-PET imaging, sensitivity, specificity and diagnostic accuracy were identical for both modalities, i.e. 90, 67 and 83%, respectively.


CONCLUSIONS
The diagnostic accuracy of (99m)Tc-depreotide SPECT is good and comparable with FDG-PET imaging in SPN of indeterminate origin.
Naalsund
Anne
A
Department of Respiratory Medicine, Rikshospitalet, Oslo, Norway. anne.naalsund@rikshospitalet.no
Maublant
Jean
J