TY - JOUR T1 - Direct Comparison of <sup>18</sup>F-FDG PET and PET/CT in Patients with Colorectal Carcinoma JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1797 LP - 1803 VL - 44 IS - 11 AU - Christian Cohade AU - Medhat Osman AU - Jeffrey Leal AU - Richard L. Wahl Y1 - 2003/11/01 UR - http://jnm.snmjournals.org/content/44/11/1797.abstract N2 - The purpose of this study was to compare 18F-FDG PET and PET/CT in a population of patients with colorectal cancer. Methods: PET and PET/CT images from 45 patients (17 women, 28 men; mean age ± SD, 60.8 ± 11.1 y) with known colorectal cancer referred for PET from June to November 2001 were retrospectively reviewed. Images were acquired with a PET/CT scanner, and 68Ge attenuation correction was applied. PET images and fused 68Ge attenuation–corrected PET and CT images were independently and separately interpreted by a moderately experienced reader unaware of the clinical information. Certainty of lesion characterization was scored on a 5-point scale (0 = definitely benign, 1 = probably benign, 2 = equivocal, 3 = probably malignant, 4 = definitely malignant). Lesion location was scored on a 3-point scale (0 = uncertain, 1 = probable, 2 = definite). The presence or absence of tumor was subsequently assessed using all available clinical, pathologic, and follow-up information. Analysis was provided for lesions detected by both PET and PET/CT. Results: The frequency of equivocal and probable lesion characterization was reduced by 50% (50 to 25) with PET/CT, in comparison with PET. The frequency of definite lesion characterization was increased by 30% (84 to 109) with PET/CT. The number of definite locations was increased by 25% (92 to 115) with PET/CT. Overall correct staging increased from 78% to 89% with PET/CT on a patient-by-patient analysis. Conclusion: PET/CT imaging increases the accuracy and certainty of locating lesions in colorectal cancer. More definitely normal and definitely abnormal lesions (and fewer probable and equivocal lesions) were identified with PET/CT than with PET alone. Staging and restaging accuracy improved from 78% to 89%. ER -