Comparing the diagnostic effectiveness of PET/CT versus stand-alone CT in the staging of non-small cell lung cancer (NSCLC) before thoracic surgery.

PURPOSE: The aim of our study was to compare the diagnostic effectiveness of PET/CTversus stand-alone CT in the staging of non-small cell lung cancer (NSCLC) before thoracicsurgery.MATERIALS AND METHOD: From August 2006 to January 2008, this retrospectivestudy included 49 patients (4 women, 45 men; mean age 63,3) with NSCLC. PET/CT andstand-alone CT images which obtained before thoracic surgery, were evaluated separately bytwo different physician teams for each imaging modality. Tumor stages were determined byusing TNM and AJCC staging systems. Histopathological results were used as gold standard.McNemar tests were applied for the diagnostic difference between PET/CT and stand-aloneCT. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negativepredictive value (NPV) for both modalities were calculated in the staging of the disease.RESULTS: Histopathologically, the distribution of tumor stages was T1 in 11 patients, T2 in21 patients, T3 in 8 patients and T4 in 9 patients. N0 disease in 31 patients, N1 in 13 patientsand N2 in 5 patients were present in the study. Overall tumor stage was correctly determinedin 39 patients (%77,6) at PET/CT and 40 patients (%81,6) at stand-alone CT. There was nostatistically signifant difference between PET/CT and stand-alone CT in terms of tumorstaging (p>0,05). For the depiction of the locoregional lymph node metastasis, the sensitivity,specificity, accuracy, PPV and NPV of PET/CT were 64%, 97,2%, 93,7%, 72,2% and 95,8%,respectively; whereas those of stand-alone CT were 72%, 93,4%, 91,2%, 56,3% and 96,6%.False-negative interpretations of malignant nodes were 9 at PET/CT and 7 at stand-alone CT,respectively. When PET/CT was compared with stand-alone CT for the false positiveinterpratations of non-malignant nodes, there were 6 false-positive interpretations at PET/CTand 14 at stand-alone CT.CONCLUSION: The results of this study showed that PET/CT had no significant superiorityover stand-alone CT images in the staging of NSCLC. Despite discrepancy of our datacompared to the results of other similar studies, it seems more likely to be related to therelatively higher number of patients with early nodal stage disease in the present study.