The aim of this study was to evaluate the clinical value of tomographic 99m Tc-octreotide acetate (hereafter, 99m Tc-octreotide) scintigraphy in the detection of patients with suspected lung cancer in comparison with that of 18 F-FDG dual-head coincidence imaging (DHC). Methods: Forty-four consecutive patients with suspected pulmonary neoplasms underwent tomographic 99m Tc-octreotide scintigraphy and 18 F-FDG coincidence imaging using the same gantry. The region of interest was drawn on the entire primary lesion. The tumor-to-normal tissue tracer values for both 99m Tc-octreotide and 18 F-FDG were determined using region of interests and expressed as T/N r and T/N m , respectively. Final diagnosis was confirmed by histopathologic analysis or clinical follow-up. Results: Thirty-one of the 44 patients had lung cancer-6 with small cell lung cancer (SCLC) and 25 with non-small cell lung cancer (NSCLC). Thirteen of the 44 patients had benign lung lesions. The sensitivity, specificity, positive predictive value, and negative predictive value of 99m Tc-octreotide were 100%, 75.7%, 90.1%, and 100%, respectively, and of 18 F-FDG DHC were 100%, 46.1%, 83.8%, and 100%, respectively. In the 31 patients with malignant tumors, all 38 abnormal lymph nodes in 20 patients showed abnormal high focal uptake of 18 F-FDG; only 7 patients with 10 regional lymph adenopathies showed moderate uptake of 99m Tc-octreotide. Thirteen patients with 39 distant sites of abnormal uptake visualized (imaging stage IV) with 99m Tc-octreotide included 2 patients with brain metastases, 6 patients with pleural invasion and multiple bone metastasis, 2 patients with contralateral internal lung metastasis and pleural invasion, and 3 patients with only multiple bone metastasis. The final diagnosis was confirmed by histopathology or clinical follow-up. Conclusion: The sensitivity of 99m Tc-octreotide for the detection of lung cancer at the primary lesion was comparable with that of 18 F-FDG coincidence imaging. Tomographic 99m Tc-octreotide scintigraphy had lower sensitivity for the detection of hilar and mediastinal lymph node metastasis compared with that of 18 F-FDG coincidence PET, but it had high sensitivity for the detection of remote metastatic lesions. However, because of the small population, further investigation is necessary.

No abstract