Additional value of whole-body positron emission tomography with fluorine-18-2-fluoro-2-deoxy-D-glucose in recurrent colorectal cancer

Purpose: To assess the additional value of the whole-body [F-18]-2-fluoro-2 -deoxy-D-glucose positron emission tomography (FDG-PET) scan as a staging m odality complementing conventional diagnostic methods (CDM) in patients sus pected of having recurrent colorectal adenocarcinoma. Patients and Methods: In 103 patients, the discordances between FDG-PET and CDM results were identified and related to the final diagnosis obtained by histopathology or clinical follow-up (> 1 year), All FDG-PET studies were reviewed with full knowledge of the CDM findings, Results: In a region-based analysis, discordances between CDM and FDG-PET f indings were found in 40 of 412 regions (10%), In these, FDG-PET had additi onal diagnostic value in 14 of 16 locoregional, six of seven hepatic, seven of eight abdominal, and eight of nine extra-abdominal regions. In a patien t-based analysis, CDM categorized a subgroup of 60 patients as having resec table recurrent disease limited to the liver (n = 37) or locoregional regio n (n = 23), In 13 of these patients, there were discordant FDG-PET findings , detecting additional tumor sites in nine patients and excluding disease i n three patients and yielding an additional diagnostic value in 20% of the patients. A second subgroup consisted of 13 patients with inconclusive CDM findings (n = 5) or with elevated plasma carcinoembryonic antigen levels an d an otherwise negative conventional work-up (n = 8), In these patients, FD G-PET results were correct in eight of nine discordances, yielding a positi ve additional diagnostic value in 62% of the patients. Conclusion: Whole-body FDG-PET can have a clear impact on the therapeutic m anagement in the follow-up of patients with colorectal cancer. (C) 1999 by American Society of Clinical Oncology.