PET/CT in anal cancer - is it worth doing?
OBJECTIVE
To evaluate the role of 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)/ computed tomography (CT) in the current multidisciplinary management of anal cancer, both in initial staging and in follow-up post-treatment.


METHODS
All patients referred to the region-wide multidisciplinary meeting for anal cancer during the study period received PET/CT imaging in addition to conventional imaging [CT and magnetic resonance imaging (MRI)]. Whether PET/CT altered the stage of the tumour from that suggested by conventional imaging was retrospectively assessed. The effect on management was evaluated.


RESULTS
Fifty PET/CT examinations were performed on 44 patients with anal cancer. Thirty were part of initial staging, and 20 were post-chemo/radiotherapy or surgery. Two PET/CTs produced inadequate contemporaneous conventional imaging to allow comparison. Overall PET/CT increased the stage of the anal cancer in 17% of cases (8/48), decreased the stage in 19% (9/48), and did not alter the stage in 65% (31/48). The tumour stage was altered more frequently in initial staging than in follow up imaging. The PET/CT findings altered patient management in 29% (14/48) of cases. The majority (11) of these were cases in which PET/CT was used as part of initial staging.


CONCLUSIONS
PET/CT alters the initial staging sufficiently frequently that it should be used routinely in anal cancer, where it is available. The role of PET/CT in the follow-up of anal cancer is not as clear. Routine follow-up with PET/CT may not be justified, but selected use is of definite benefit in problem solving or if salvage surgery is planned, after multidisciplinary discussion.
Department of Radiology, Derriford Hospital, Plymouth, Devon, UK. tobywells@doctors.net.uk
I T
IT
Wells
B M
BM
Fox
D001005:Anus Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D064847:Multimodal Imaging / Q000379:methods*; D009367:Neoplasm Staging / Q000379:methods; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18