Newly published data indicate the sensitivity of 18F-fluorodeoxyglucose (18F-FDG)–PET for the detection of recurrent disease. A total of 88 patients with no, or equivocal signs of recurrence on clinical examination, but who had raised carcinoembryonic antigen (CEA) levels were examined using 18F-FDG–PET. Recurrent disease was detected in 56 patients, 49 of whose disease was identified using 18F-FDG–PET, with a sensitivity and specificity of 88%. Many of these patients went on to receive treatment with curative intent, thus indicating the importance of early detection of recurrent disease.