ABSTRACT
PURPOSE: To assess the additional value of the whole-body [18F]-2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) scan as a staging modality complementing conventional diagnostic methods (CDM) in patients suspected 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 findings were found in 40 of 412 regions (10%). In these, FDG-PET had additional diagnostic value in 14 of 16 locoregional, six of seven hepatic, seven of eight abdominal, and eight of nine extra-abdominal regions. In a patient-based analysis, CDM categorized a subgroup of 60 patients as having resectable recurrent disease limited to the liver (n = 37) or locoregional region (n = 23). In 13 of these patients, there were discordant FDG-PET findings, detecting additional tumor sites in nine patients and excluding disease in 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 and an otherwise negative conventional work-up (n = 8). In these patients, FDG-PET results were correct in eight of nine discordances, yielding a positive additional diagnostic value in 62% of the patients. CONCLUSION: Whole-body FDG-PET can have a clear impact on the therapeutic management in the follow-up of patients with colorectal cancer.
Subject(s)
Colorectal Neoplasms/diagnostic imaging , Neoplasm Recurrence, Local/diagnostic imaging , Abdominal Neoplasms/secondary , Adult , Aged , Aged, 80 and over , Colorectal Neoplasms/surgery , Female , Fluorine Radioisotopes , Humans , Liver Neoplasms/secondary , Lung Neoplasms/secondary , Male , Middle Aged , Neoplasm Staging , Retrospective Studies , Tomography, Emission-Computed/methods , Whole-Body CountingABSTRACT
The clinical value of total body PET with FDG was evaluated in 76 patients presenting with or suspected of recurrent local or distant colorectal cancer. PET results were compared to those of routine imaging (CT pelvis, CT/US liver and CXR). The accuracy of PET for local disease was 95% which was superior to CT-pelvis (accuracy 65%). PET accuracy for liver metastases (98%) compared favourably to CT/US-liver accuracy (93%). Unexpected extra-hepatic mestastases were detected by PET in 14 locations in 10 patients. Also, a primary breast cancer was found in one patient. The main value of PET appeared an improved staging of apparently resectable, local or distant recurrent disease. Thereby, a more adequate indication of major secondary surgery could be attained.
