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.