The usefulness of combined diagnostic CT and (99m)Tc-octreotide somatostatin receptor SPECT/CT imaging on pulmonary nodule characterization in patients.

UNLABELLED

The objective of this study was to evaluate the clinical value of combination of diagnostic computed tomography (CT) and somatostatin receptor imaging with (99m)Tc-octreotide acetate SPECT/CT in differentiation of benign pulmonary nodules from cancers.

METHODS

This was a retrospective study, 29 patients with suspected pulmonary neoplasm underwent diagnostic CT and (99m)Tc-octreotide SPECT/CT scans, and the tumor-to-normal tissue tracer value (T/N) for (99m)Tc-octreotide was measured. Diagnosis was confirmed by histological analysis.

RESULTS

Eighteen of the 29 patients included in this study had lung cancer: 2 with small cell lung cancer and 16 with nonsmall cell lung cancer. The other 11 patients had benign lung lesions: 5 with tuberculosis, 4 with nontuberculosis infection, 1 with hematoma, and 1 with fibroma. (99m)Tc-octreotide uptake (expressed as mean T/N±SD) was significantly higher in lung cancers (2.58±0.91) than benign lesions (1.38±0.79) (p=0.002). Specificity for pulmonary malignant nodule diagnosis was 63.6% for diagnostic CT, 72.7% for somatostatin receptor SPECT/CT imaging, and 81.8% for the combined use of diagnostic CT and somatostatin receptor SPECT/CT imaging.

CONCLUSION

Somatostatin receptor imaging with (99m)Tc-octreotide SPECT/CT is useful for the differentiation of benign pulmonary nodules from lung cancers, the combination of diagnostic CT and (99m)Tc-octreotide SPECT/CT further increases the specificity of malignant pulmonary nodule detection.