F-18-2-fluoro-2-deoxyglucose positron emission tomography compared to technetium-99m hexakis-2-methoxyisobutyl isonitrile single photon emission chest tomography in the diagnosis of indeterminate lung lesions.

Background: (18)FDG-PET plays a significant role in diagnosing malignancy of lung lesions but remains an expensive test available at a limited number of sites in Italy.

Objective: We prospectively compare the diagnostic accuracy of (99m)Tc-MIBI- SPECT and (18)FDG-PET in patients with indeterminate lung lesions to demonstrate that (99m)Tc-MIBI-SPECT may be considered as a valid alternative when (18)FDG-PET is not available.

Methods: 52 patients with indeterminate lung lesion were examined by (18)FDG-PET and (99m)Tc-MIBI-SPECT before surgery. The scintigraphic findings were analyzed visually and semiquantitatively and then correlated to the definitive diagnosis.

Results: 38 were malignant lesions while 14 were benign. At visual analysis, the sensitivities of (18)FDG-PET and (99m)Tc-MIBI-SPECT were 92 and 84%, respectively (McNemar test p = 0.4), whereas the specificities were 78.6 and of 93% (p = 1.0), respectively. At semiquantitative analysis, (18)FDG-PET showed a sensitivity and specificity of 92 and 71.4%, respectively, while (99m)Tc-MIBI-SPECT produced a sensitivity and specificity of 86 and 100%, respectively (p = 0.194). For lymph node staging, (18)FDG-PET and (99m)Tc-MIBI-SPECT have a sensitivity and specificity of 88 and 92 of 77 and 100%, respectively.

Conclusion: (99m)Tc-MIBI-SPECT is similar to (18)FDG-PET in the detection of lung malignancies and represents an alternative when PET is not available. Yet, the combination of both techniques may improve patient selection for surgery.