Integrated 18F-FDG PET/CT and perfusion CT of primary colorectal cancer : effect of inter- and intraobserver agreement on metabolic-vascular parameters

The purpose of this article is to assess the effect of observers on combined metabolic-vascular parameters in colorectal cancer. Twenty-five prospective patients (12 men and 13 women; mean age, 66.9 years) with proven primary colorectal adenocarcinoma underwent integrated 18F-FDG PET/perfusion CT to assess tumor metabolism (mean and maximum standardized uptake value [SUVmean and SUVmax, respectively]) and vascularization (blood flow [BF], blood volume [BV], permeability surface-area product, and standardized perfusion value). Intra- and interobserver agreement for PET, perfusion CT, and combined metabolic-flow parameters were determined by Bland-Altman statistics and intraclass correlation coefficients (ICCs).