The role of whole-body positron emission tomography with [18F]fluorodeoxyglucose in identifying operable colorectal cancer metastases to the liver

Abstract

Objective: To compare the accuracy of whole-body positron emission tomography (PET)using [18F]fluorodeoxyglucose (FDG) with conventional radiological imaging techniques in identifying operable colorectal cancer metastases to the liver. Design: A double-blind comparative study of FDG-PET as the criterion standard vs conventional radiological imaging methods as the criterion standard, in staging of recurrent colorectal cancer. Setting: Institutional practice in a tertiary referral center. Patients: Thirty-four consecutive patients with suspected colorectal cancer metastases, recruited for the study between May 1993 and October 1994. Interventions: Conventional radiological methods of cancer staging included abdominal computed tomography (CT) (n=34), chest x-rays (n=15), and chest CT (n=19) to evaluate extrahepatic disease. Twenty-seven patients were subsequently considered to have apparently isolated cancer metastases to the liver. Anatomical resectability was assessed by magnetic resonance imaging (n=24) or CT angiography (n=3) in all study patients. The FDG-PET studies (n=34) were performed within 8 weeks of conventional radiological imaging. Main Outcome Measures: Malignancy of suspected lesions detected by means of FDG-PET and conventional radiological imaging was confirmed by histopathologic examination of resected specimens and percutaneous biopsy specimens and by serial CT scans demonstrating progression of disease. Results: Unsuspected extrahepatic malignant disease that was missed by conventional radiological imaging was detected by FDG-PET in 11 patients (32%). The PET-detected extrahepatic malignant disease included retroperitoneal nodal metastases (n=6), pulmonary metastases (n=3), and locoregional cancer recurrences (n=2). The additional information afforded by PET consequently had an influence on the clinical management in 10 patients (29%). Conclusion: The FDG-PET method enabled selection of patients with apparently curable colorectal cancer metastases to the liver for hepatic resection.