FDG-PET and colon cancer

Imaging colorectal cancer has become a major indication for positron emission tomography using fluorodeoxyglucose (FDG–PET). In primary diagnosis and staging, the role for this technique is limited but FDG–PET has proved highly accurate in the detection of recurrent tumour. The three main indications are (i) characterisation of a residual structural lesion after definitive therapy, (ii) pre-operative staging prior to resection of apparently isolated metastasis, and (iii) investigation of rising carcinoembryonic antigen (CEA) in a patient with normal structural imaging. The diagnostic accuracy of FDG–PET translates to changes in management in a large number of patients, resulting in improved costeffectiveness. FDG–PET is fast becoming the standard of clinical care for patients with recurrent colorectal cancer.