Generating evidence for clinical benefit of PET/CT in diagnosing cancer patients.

For diagnostic methods such as PET/CT, not only diagnostic accuracy but also clinical benefit must be demonstrated. However, there is a lack of consensus about how to approach this task. Here we consider 6 clinical scenarios to review some basic approaches to demonstrating the clinical benefit of PET/CT in cancer patients: replacement of an invasive procedure, improved accuracy of initial diagnosis, improved accuracy of staging for curative versus palliative treatment, improved accuracy of staging for radiation versus chemotherapy, response evaluation, and acceleration of clinical decisions. We also develop some guidelines for the evaluation of clinical benefit. First, it should be clarified whether there is a direct benefit of the use of PET/CT or an indirect benefit because of improved diagnostic accuracy. If there is an indirect benefit, then decision modeling should be used initially to assess the benefit expected from the use of PET/CT. Only if decision modeling does not allow definitive conclusions should randomized controlled trials be planned.