FDG-PET Improves Management of Patients with Colorectal Liver Metastases Allocated for Local Treatment: A Consecutive Prospective Study

Background and Aim: Colorectal cancer is a common cancer in the Nordic countries and 50% of the patients develop liver metastases. Liver resection may result in long term survival. Proper staging is therefore essential and CT is the standard imaging modality. We examined whether additional FDG-PET improves therapeutic management of patients with colorectal liver metastases. Patients and Methods: Fifty-four consecutive patients were enrolled. Each patient had a treatment plan made based on our standard evaluation. The patients then had a PET scan and the treatment plan was re-evaluated, taking these results into account. Results: In 76% of the cases, PET did not change the treatment plan due to complete concordance with CT. In another 19% of the cases, the plan was altered due to finding of more liver lesions by PET than by CT (four patients), fewer or no liver lesions (three patients), and extrahepatic lesions not visible on CT (three patients). In 5% of the cases, non-concordance between PET and CT did not change the therapeutic plan. Conclusion: Pre-treatment FDG-PET, used supplementary to CT, improved the treatment plan in one fifth of the patients with colorectal liver metastases.