[Reevaluation of 201Tl-SPECT for patients with solitary pulmonary nodule--comparison study with biopsy method and...

We compared the differential diagnostic capabilities of 201Tl-SPECT and biopsy methods and serum tumor marker in 125 patients with solitary pulmonary lesions composed of 87 lung cancer and 38 benign lesions. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of 201Tl-SPECT were 76%, 95%, 97%, 63%, and 82%, respectively. These parameters are similar in biopsy methods. Although sensitivity improved to be 85% by the combination with tumor marker methods, both specificity and accuracy deteriorated to be 55% and 76%. Using combination method with 201Tl-SPECT and biopsy, sensitivity, NPV and accuracy improved to be 84%, 70% and 85%. Based on its high PPV value, 201Tl-SPECT could be useful when biopsy method could not prove lung cancer or in case whose biopsy is considered to be invasive. Because of the lower NPV value owing to false negative cases in some adenocarcinoma, negative 201Tl-SPECT case should be followed up carefully.