The purpose of this research is to compare the association between the diagnostic values of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18FDG PET/CT) scan (maximum standardized uptake value - SUV) for pre-operative lymph nodes status and the final histopathology report.
This retrospective study gathered the information from patient medical records at Bangkok Hospital Medical Center. The patients were examined for colorectal cancer from May 2007 to November 2009 and received the pre-operative positron emission tomography/computed tomography (PET/CT) scan before having oncologic colorectal surgery during the time period mentioned above. The subjects in this study numbered 30 patients. Each 18FDG PET/CT scan was reviewed and interpreted by one nuclear medicine professional who had no prior knowledge of patient details, including the diagnosis of any previous PET/CT scans.
Results demonstrated that the PET/CT scan correctly identified 24 out of 30 patients to have pre-operative lymphadenopathies. Moreover, 14 out of those 24 patients (58.3%) showed metastatic lymphadenopathies in the final histopathology. The remaining 2 out of 6 patients (33.3%) had metastatic lymphadenopathies according to final histopathology, but 18FDG PET/CT did not detect them. There was a significant differentiation (p = 0.014) between the mean of the SUV in malignant lymphadenopathies (1.18 ± 0.69) and those of benign lymphadenopathies (0.59 ± 0.54) in primary colorectal cancer patients.
There was a clear association between preoperative diagnosis of suspicious malignant lymphadenopathies by PET/CT scan and final histopathological lymphadenopathies. It will be beneficial to see further studies about the predictive role of using pre-operative 18FDG PET/CT scanning in diagnosis of lymph node metastasis in colorectal cancer patients. The pre-operative PET scans of our colorectal cancer patients showed a higher uptake of 18F-fluorodeoxyglucose (18FDG) in malignant lymph nodes.
18FDG-PET/CT, colorectal cancer, lymph node metastasis