Objective: To compare the accuracy of whole-body position 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%).
Conclusions: The FDG-PET method enabled selection of patients with apparently curable colorectal cancer metastases to the liver for hepatic resection.