BACKGROUNDAn accurate pre-operative tumor staging is the premise for a successful operation, for which a non-invasive evaluation of the nature of lung nodules and the real extent of them is necessary. As the pioneer of functional images, nuclear medicine continues to introduce novel radiopharmaceuticals and new techniques for cancer imaging, including tetrofosmin (TF). The aim of this study is to evaluate the clinical usefulness of 99m Tc-tetrofosmin SPECT ( 99m Tc-TF SPECT) in the diagnosis of lung cancer and mediastinal lymph node involvement.

METHODSThirty-three patients with pulmonary neoplasms took both CT scan and 99m Tc-TF SPECT in one week before their operations or puncture biopsy. Then the sensitivity, specificity and accuracy were acquired according to the pathological outcomings and the results of 99m Tc-TF SPECT and CT were compared in detection of lung cancer and mediastinal lymph node metastasis, respectively.

RESULTSThe sensitivity, specificity, accuracy, positive predictive value and negative predictive value of 99m Tc-TF SPECT for lung cancer were 95.7%, 80.0%, 90.9%, 91.7%, 88.9%, and 73.9%, 70.0%, 72.7% , 85.0% , 53.8% by CT, respectively. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of 99m Tc-TF SPECT for mediastinal lymph node metastasis were 93.3%, 75.0%, 87.0% , 87.5%, 85.7%, while those of CT were 60.0%, 75.0%, 65.2%, 81.8%, 50.0% respectively. The sensitivity of 99m Tc-TF SPECT was significantly higher than that of CT for lung neoplasms (P < 0.05).

CONCLUSIONS99m Tc-TF SPECT is a useful non-invasive presurgical tool to evaluate primary lung cancers and mediastinal lymph node involvement, and it will play a favorable clinical role in diagnosis and staging of lung cancer.