Which FDG/PET parameters of the primary tumors in colon or sigmoid cancer provide the best correlation with the pathological findings?

Background To compare 18F-fluoro-2-deoxdeoxyglucose (FDG) positron emission tomography (PET) related parameters of primary colon or sigmoid cancer (CSC) with pathological findings.Methods Seventy-seven CSC patients who have undergone preoperative PET computed tomograms (PET/CT) are included in this study. Maximum PET-based tumor length (TL) and tumor width (TW) are determined using several auto-segmentation methods, and various thresholds of metabolic tumor volume (MTV) and total lesion glycolysis (TLG) are measured. The PET-based TL and TW are compared with maximum pathological length and width on the pathological specimen.Results Using a 30% threshold level for maximum uptake of TL (TL30%) and TW (TW30%) yield results that provide an optimal match with maximum pathological length (R = 0.81, p < 0.001) and width (R = 0.70, p < 0.001). TW30% was an independent factor for predicting pathological T3 or T4 stages (OR = 1.26, 95% CI = 1.07–1.47, p = 0.01). The receiver-operating characteristic curves show MTV at a fixed threshold of 40% maximum uptake (MTV40%), and TW30% achieved better correlation with the advanced pathological T stage. No associations with positive N stage were observed.Conclusion Pretreatment PET/CT is a useful tool for predicting the final pathological findings for CSC patients requiring surgical procedures.