Few data exist on the medicoeconomic usefulness of PET in the management of metachronous liver metastases from colorectal cancer. This study was designed to assess the cost-effectiveness of PET in the diagnosis and staging of patients with metachronous liver metastases of colorectal cancer using a decision analysis model.
Methods: Two alternatives were compared: CT and CT associated with PET (CT+PET). Transition probabilities were estimated from published data and consultations with experts. Survival data were provided by the Burgundy Digestive Cancer Registry (France). Costs of imaging techniques and treatments were assessed using reimbursements from the French health care insurance for the year 2004. Evaluation criteria included incremental cost-effectiveness ratios and the proportion of unnecessary operations avoided in patients without metachronous liver metastases.
Results: CT+PET was the most cost-effective strategy, presenting an expected incremental cost saving of 2,671 (approximately $3,213) per patient, for the same level of expected effectiveness as CT alone (1.88-y life expectancy per patient). Sensitivity analyses performed on epidemiologic and economic parameters showed that this model was robust. The model also suggested that CT+PET could avoid exploratory surgery for 6.1% of patients-that is, 88.4% risk reduction compared with CT alone.
Conclusion: PET for diagnosis and staging does not generate additional survival effectiveness compared with CT alone. However cost savings associated with its use and the improvement of therapeutic management therefore justify its generalization in clinical practice.