| [ Summary ] |
Approximately 50% of patients diagnosed with colorectal cancer will develop liver metastases with five years. The five year survival rate after hepatic resection is about 40%. Many patients are thought to have been harboring tumor foci unrecognized by X-ray CT at the time of liver resection. Positron emission tomography (PET) with [F-18] FDG (fluorodeoxyglucose) is a sensitive diagnostic tool based on visualizing increased glucose metabolic activity in tumor tissue. The sensitivity, accuracy, and specificity in the diagnoses for colorectal liver metastases with FDG PET seans shown in a meta-analysis was 96.3%, 99.0, and 97.7% respectively. X-ray CT, even a helical CTs, can often not differentiate metastases and benign diseases when the lesion is small. FDG PET has produced higher over-all accuracy in the diagnoses of liver metastases than any other imaging method, although it's sensitivity is reduced in cases with small lesions. FDG PET scans can also improve the therapeutic management of patients with liver metastases by detecting unsuspected extra-hepatic metastases. FDG PET scans decrease recurrence rates in patients undergoing hepatic resection by avoiding inappropriate operations. FDG PET scanning has a strong impact on clinical management of patients with colorectal liver metastases. |