Impact of Positron Emission Tomography Imaging Prior to Liver Resection for Colorectal Adenocarcinoma Metastases

Colorectal cancer remains a leading cause of death in men and women. A significant number of patients with colorectal cancer will either present with, or subsequently develop, liver metastases. In contrast to many other epithelial solid tumours, resection of colorectal cancer hepatic metastases results in long-term survival and even cure. However, despite state of the art CT imaging, 60-75% of patients who appear to have limited disease amenable to surgical resection will eventually die from extra-hepatic and recurrent hepatic metastases. If occult micrometastatic disease that becomes evident after liver resection could be detected reliably during pre-operative assessment, patients harboring more widespread disease could be spared a non-curative liver resection. This is one of the present challenges of liver surgery. PET imaging has the potential to improve the detection of both hepatic and extra-hepatic metastatic disease, not detected by conventional imaging modalities.

This prospective, multicenter trial will enroll patients with colorectal cancer liver metastases considered resectable, based on CT scans of the thorax, abdomen and pelvis, which demonstrate no evidence of extra-hepatic disease. A full colonoscopy within the preceding 12 months will ensure there is no local recurrence, or other primary cancer at the time of planned liver resection. These patients will be randomized to PET scan or not.

Inclusion criteria

• Histologic proof of previous colorectal adenocarcinoma (not carcinoid, squamous cell cancer, gastrointestinal stromal tumor, or lymphoma)
• Contrast-enhanced spiral CT scan of the thorax, and a tri-phasic CT scan of the abdomen and pelvis performed within 30 days (plus up to 14 days) before randomization demonstrating resectable metastasis(es) that are isolated to the liver
• Full colonoscopy performed within the preceding 18 months showing no evidence of malignancy (other than a synchronous colorectal primary expected to be removed at time of liver resection)
• Age over 18 years

Exclusion criteria

• Extrahepatic disease including enlarged portal lymph nodes on CT
• Prior liver resection
• Previous radiofrequency ablation of malignant liver lesion
• Systemic chemotherapy within three weeks prior to randomization
• Radiotherapy within two months prior to randomization
• Significant concurrent medical problems (e.g., uncontrolled diabetes, active cardiac disease, significant chronic obstructive pulmonary disease) making the patient unfit for surgery
• Pregnant or lactating female
• Unable to lie supine for imaging with PET
• Previously treated cancer other than non-melanocytic skin cancer or carcinoma in situ of the cervix, unless disease-free for 5 years or greater
• Patients who, at the time of the initial evaluation, have already undergone a whole body PET within 6 months prior to randomization