Visualization of lung cancer with Tc-99(m)-tetrofosmin imaging: A comparison with Tl-201

We evaluated the usefulness of Tc-99(m)-tetrofosmin imaging in lung cancer. The study sample comprised 46 patients with lung cancer. Single photon emission tomography was conducted after the intravenous injection of 740 MBq Tc-99(m)-tetrofosmin and 111 MBq Tl-201-chloride. We obtained an uptake ratio (counts per pixel in the lesion/counts per pixel in contralateral normal lung) for each scan to evaluate the degree of uptake in the tumour. Our results demonstrate that 89.1% of the primary lung cancers were visualized by Tc-99(m)-tetrofosmin and 95.7% by Tl-201. The difference between the Tl-201 uptake ratio and the Tc-99(m)-tetrofosmin uptake ratio was significantly greater in squamous cell carcinomas than small cell carcinomas (P < 0.01) and tended to be greater in squamous cell carcinomas than adenocarcinomas (P = 0.093). This study has indicated that Tc-99(m)-tetrofosmin, like Tl-201, is a highly effective agent in the delineation of lung cancer. The difference between the Tc-99(m)-tetrofosmin and Tl-201 uptake ratios might provide further information regarding the histological type of lung cancer.