DECISION TREE SENSITIVITY ANALYSIS FOR COST-EFFECTIVENESS OF FDG-PET IN THE STAGING AND MANAGEMENT OF NON-SMALL-CELL LUNG-CARCINOMA

Preliminary studies have shown that PET is more accurate than CT for t he staging of non-small-cell lung carcinoma (NSCLC). However, the pote ntial effect of PET on the management of these patients and its cost-e ffectiveness has not been rigorously studied. Thus, we have used decis ion tree sensitivity analysis to assess the cost-effectiveness of a PE T based strategy for staging of NSCLC. Methods: Two decision strategie s for selection of potential surgical candidates were compared; thorac ic CT alone or thoracic CT and thoracic PET. The first decision tree w as conservatively constructed by requiring mediastinoscopy (biopsy) to confirm imaging results so that no patient with surgically curable di sease would miss the opportunity for surgery in either strategy. A sec ond less conservative tree in which only nonconcordant results are bio psied was also tested. The various paths of each strategy are dependen t on numerous parameters which were determined from a review of the me dical literature. Life expectancy was calculated using the declining e xponential approximation of life expectancy and reduced based on proce dural mortality. Costs were based on mean costs at our institution. Fo r all possible outcomes of each strategy, the expected cost and projec ted life expectancy were determined. The effect of changing one or mor e parameters on the expected cost and life expectancy were studied usi ng a sensitivity analysis. Results: The CT + PET strategy in the conse rvative decision tree showed a saving of $1154 per patient without a l oss of life expectancy (increase of 2.96 days) as compared to the alte rnate strategy of CT alone. Both these effects were the result of impr oved staging of lung carcinoma prior to the decision for surgery. The CT + PET strategy in the less conservative decision tree showed a savi ngs of $2267 per patient but misses 1.7% of potentially operable patie nts. Conclusion: These results show through rigorous decision tree ana lysis, the potential cost-effectiveness of using FDG PET in the manage ment of NSCLC. These results form a basis for detailed study of the re sults obtained from multicenter trials on the accuracy of PET in NSCLC management. Furthermore, the techniques utilized for decision tree an alysis have broad range of applicability to the entire field of nuclea r medicine.