Clinical application of PET/CT in diagnosis and staging of patients with non-small-cell lung cancer: comparison with PET

Purpose: To evaluate the clinical value of integrated positron-emission tomography and computed tomography(PET/CT) in diagnosis and Staging of patients with non-small-cell lung cancer and to compare the diagnostic and Staging accuracy with PET alone. Methods: PET/CT was performed in 42 patients (6 women, 36 men; mean age ±SD, 57.9 ±12.7 y) with proven or suspected non-small-cell lung cancer. All studies were retrospectively reviewed by two moderately experienced physicians unaware of the clinical information. PET/CT and PET images were evaluated independently and separately. Focal fluorodeoxyglucose (FDG) uptake on attenuation-corrected PET images was scored on a 5-point scale (0 = definitely benign, 1 = probably benign, 2 = equivocal, 3 = probably malignant, 4 = definitely malignant). PET/CT images were then reviewed. Comparison was performed on a lesion-by-lesion basis. Accuracy was evaluated on the basis of follow-up, histopathologic findings or at least one other imaging method. Tumor-node-metastasis (TNM) stage was assigned on the basis of image analysis. Results: A total of 201 foci with abnormal FDG uptake were noted, two of which were seen only on PET/CT images. The sensitivity, specificity and accuracy for detection of primary cancer were 94, 100, and 95% with PET/CT. PET/CT provided additional information over the separate interpretation of PET and CT in 24 patients (57%) with 57 sites (28%). In comparison with PET, the frequency of equivocal and probable lesion characterization was reduced by 57% (63 to 27) with PET/CT The frequency of definite lesion characterization was increased by 23% (141 to 174) with PET/CT Overall correct staging increased from 81% to 89% with PET/CT on a patient-by-patient analysis. Conclusions: Compare to PET alone, PET/CT improves the accuracy in the diagnosis and staging of non-small-cell lung cancer. More definitely normal and definitely abnormal lesions were identified with PET/CT than with PET alone. (authors)