The solitary pulmonary nodule--is it malignant or benign? Diagnostic performance of Tc-depreotide SPECT

Respiration. 2006;73(5):634-41. doi: 10.1159/000093232. Epub 2006 May 5.


Background: The diagnosis of malignancy may be difficult to establish in solitary pulmonary nodules (SPNs).

Objectives: 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.

Publication types

  • Comparative Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Fluorodeoxyglucose F18
  • Humans
  • Lung Neoplasms / diagnostic imaging
  • Male
  • Middle Aged
  • Organotechnetium Compounds*
  • Positron-Emission Tomography
  • Prospective Studies
  • Radiopharmaceuticals
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Solitary Pulmonary Nodule / diagnostic imaging*
  • Somatostatin / analogs & derivatives*


  • Organotechnetium Compounds
  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18
  • Somatostatin
  • technetium Tc 99m depreotide