The clinical usefulness of (99m)Tc-Tetrofosmin scintigraphy in the diagnosis of lung neoplasmas and mediastinal lymphoid node involvement.

In order to investigate the clinical significance of (99m)Tc-Tetrofosmin (TF) scintigraphy in the evaluation of lung cancer and mediastinal lymphoid node involvement, 33 patients with pulmonary neoplasmas were subjected to both (99m)Tc-TF scintigraphies and CT scans in one week before their operations or puncturations. All the images were judged visually and the emission images were analyzed with semi-quantitative methods in addition. The results of each group were compared. There was marked difference in target/non-target (T/N) ratio between the lung cancer group and the benign lesion group (P<0.001). Moreover, in the lung cancer group, T/N ratio in tomographies was significantly higher than that in planar images (P<0.01). The sensitivity and accuracy of semi-quantitative analysis in (99m)Tc-TF SPECT were significantly higher than those of CT in the diagnosis of pulmonary neoplasmas (P<0.05 and P<0.01 respectively), so was the sensitivity of (99m)Tc-TF SPECT vs CT in the diagnosis of mediastinal lymphoid node metastasis (P<0.05). It was also found that epidermoid squamous cell carcinomas and adenocarcinomas had a higher T/N ratio than in small cell carcinomas (P<0.05), and 2 h washout rate (WR) of adenocarcinomas was higher than that of epidermoid squamous cell carcinomas (P<0.05). In conclusion, (99m)Tc-TF scintigraphy showed a favorable diagnostic accuracy in appraising lung cancers and mediastinal lymph node metastases. Furthermore semi-quantitative technology can improve the accuracy, and is potential to offer some information about histological type of the cancer tissue. Therefore, (99m)Tc-TF scintigraphy will be a useful tool in the diagnosis and staging of lung cancer.