Comparative Study on the Sensitivities and Specificities of CT and Camera Based PET Scan in Determination of Lung Cancer Staging

Abstract

A retrospective study was undertaken to compare sensitivities and specificities of computed tomography (CT) scan and radiolabeled glucose analog 18F-fluoro-2-deoxy-D-glucose (FDG) camera based positron emission tomography (PET). Nine patients with lung cancer who underwent preoperative CT and 18F-FDG coincidence PET scanning were evaluated retrospectively. Imaging studies were read prospectively and blinded to the surgical and pathologic data. The final diagnosis was established by histopathologic examination at thoracotomy. CT was accurate in 7 patients (77.8%), with understaging in 1 patient and overstaging in 1 patient. In´ detection of locally advanced disease (N2/N3), the sensitivity, specificity, positive predictive value and negative predictive value were 50%, 85.7%, 50% and 85.7%, respectively. On the other hand, ´$F-FDG-PET was accurate in 8 patients (88.9%), with overstaging in 1 patient and without any understaging. In detection of locally advanced disease (N2/N3), the sensitivity, specificity, positive predictive value and negative predictive value were 100%, 85.7%, 66.7% and 100%, respectively. 18F-FDG-PET was significantly more accurate than CT in lymph node staging of lung cancer. The high negative predictive value of FDG-PET could reduce a need for invasive surgical staging (ISS).