[Benefit assessment of PET in malignant lymphomas. The IQWiG point of view]

The call by the Institute for Quality and Efficiency in Health Care (IQWiG) for randomised controlled trials (RCTs) to prove the patient-relevant benefit of positron emission tomography (PET) is currently a controversial topic in Germany. From a methodological point of view there is essentially no difference between diagnostic procedures and therapeutic (drug or non-drug) interventions in proving their causal benefit. A broad consensus has been reached since the 1960s (e.g. FDA regulations) that RCTs are the methodological gold standard for therapeutic interventions. Nevertheless, the same arguments that were cited against RCTs in assessing the benefit of therapeutic interventions are now used against RCTs in evaluating diagnostic tests (e.g. ethical problems, feasibility, etc.). This paper summarizes the central methodological arguments of the discussion on the benefit assessment of PET in malignant lymphomas from the perspective of IQWiG and its external experts.