^(18)F-fluoro-2-deoxyglucose uptake on PET CT and glucose transporter 1 expression in colorectal adenocarcinoma

AIM:To evaluate the correlation between the level of 18 F-fluoro-2-deoxyglucose (18 F-FDG) uptake and glucose transporter 1 (GLUT1) expression in colorectal adenocarcinoma (CRA).METHODS:Forty four patients with resected CRA and preoperative 18 F-FDG positron emission tomography computed tomography data were investigated in this study.Comparison of maximum standardized uptake value (SUVmax) of the lesion was made with GLUT1 expression by immunohistochemistry and various clinicopathologic factors including tumor volume,invasion depth,gross finding,and lymph node metastasis.RESULTS:SUVmax was 14.45 ± 7.0 in negative GLUT1 expression cases,15.51 ± 5.7 in weak GLUT1 expression cases,and 16.52 ± 6.8 in strong GLUT1 expression cases,and there was no correlation between between GLUT1 expression and SUVmax.SUVmax was significantly correlated with tumor volume (P < 0.001).However,there was no significant differences in SUVmax and GLUT1 expression among other clinicopathologic factors.CONCLUSION:GLUT1 expression does not correlates significantly with 18 F-FDG uptake in CRA.18 F-FDG uptake was increased with tumor volume,which is statistically significant.

Colorectal cancer and 18FDG-PET/CT:What about adding the T to the N parameter in loco-regional staging?

AIM:To evaluate whether FDG-positron emission tomography(PET)/computed tomography(CT)may be an accurate technique in the assessment of the T stage in patients with colorectal cancer.METHODS:Thirty four consecutive patients(20 men and 14 women;mean age:63 years)with a histologically proven diagnosis of colorectal adenocarcinoma and scheduled for surgery in our hospital were enrolled in this study.All patients underwent FDG-PET/CT preoperatively.The primary tumor site and extent were evaluated on PET/CT images.Colorectal wall invasion was analysed according to a modified T classification that considers only three stages(≤T2,T3,T4).Assessment of accuracy was carried out using 95%confidence intervals for T.RESULTS:Thirty five/37(94.6%)adenocarcinomas were identified and correctly located on PET/CT images.PET/CT correctly staged the T of 33/35 lesions identified showing an accuracy of 94.3%(95%CI:87%-100%).All T1,T3 and T4 lesions were correctly staged,while two T2 neoplasms were overstated as T3.CONCLUSION:Our data suggest that FDG-PET/CT may be an accurate modality for identifying primary tumor and defining its local extent in patients with colorectal cancer.