title: Whole-Body FDG-PET in Patients with Recurrent Colorectal Carcinoma. A Comparative Study with CT.
abstract: Purpose: To assess the clinical accuracy of whole-body 2-[F-18]-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) in the diagnosis of recurrent colorectal carcinoma in comparison to conventional computed tomography (CT).Materials and methods: Forty patients with suspected recurrent colorectal carcinoma based on either progressive serial carcinoemrbyonic antigen (CEA) serum elevation or positive/equivocal CT findings underwent whole-body FDG-PET. PET results were compared with those of CT and correlated to the final histopathological and clinical findings.Results: A final diagnosis was obtained at 93 sites in 35 patients by histology and in 5 patients by clinical follow up of at least 6 months. Of the 93 sites, 53 were determined to be malignant and 40 benign. FDG-PET evaluated on a 5-point scale (0-4) showed a positive and negative predictive value in the range of 96-98% and 83-93% respectively as the threshold for positivity was moved from 0 through 3. By comparison, CT, also evaluated on a 5-point scale showed a positive and negative predictive value in the range of 75-88% and 67-71% respectively. The area under the fitted receiver operating characteristic curve for PET: A(PET) = 0.96 +/- 0.02 was significantly greater (P < 0.001) than that observed for CT: A(CT) = 0.77 +/- 0.06. The distribution of maximum standardized uptake value (SUVmax) showed that all negative lesions have SUVmax below 5.0 whereas 75% of positive lesions were above 5.0 pointing to the fact that disease positivity is more likely in lesions with high SUV values.Conclusion: The results of this study confirm that whole-body FDG-PET is more accurate than conventional CT in the staging of patients with suspected recurrent colorectal carcinoma.
authors.affiliation: Department of Biostatistics, University "Federico II", Napoli, Italy
authors.initials: M
authors.lastname: Imbriaco
authors.initials: T
authors.lastname: Akhurst
authors.initials: S
authors.lastname: Hilton
authors.initials: HW
authors.lastname: Yeung
authors.initials: HA
authors.lastname: Macapinlac
authors.initials: M
authors.lastname: Mazumdar
authors.initials: L
authors.lastname: Pace
authors.initials: N
authors.lastname: Kemeny
authors.initials: Y
authors.lastname: Erdi
authors.initials: A
authors.lastname: Cohen
authors.initials: Y
authors.lastname: Fong
authors.initials: J
authors.lastname: Guillem
authors.initials: SM
authors.lastname: Larson