Clinical Trials

In a clinical trial setting, imaging studies can be used in a variety of clinical indications depending on the scientific aim and needs of the trials including screening, diagnosis, staging, as a prognostic or predictive biomarker, and for the evaluation of response to treatment. Currently, imaging studies are most often studied in oncology as part of a secondary or correlative science objective within a clinical trial which is investigating another therapeutic agent. However, imaging trials may sometimes be studied as the primary objective of a clinical trial without additional evaluation of a therapeutic regimen. How best to structure the trial will depend on the imaging scientific question that is being asked and the current level of evidence available to support the question.

Like therapeutic clinical trials, imaging clinical trials share many of the same characteristics in study structure and design. For instance, imaging clinical trials are often times described using the same Phase 1/2/3 paradigm commonly seen in oncology trials. Furthermore, in studies where agents are administered to patients as part of the imaging procedure, such as radioactive tracers for Nuclear Medicine studies or imaging contrast for anatomic CTs or MRIs, the imaging agent or contrast is often times treated in the same manner as therapeutic agents in terms of regulatory status and adverse event reporting.

However, while there are certainly similarities, imaging clinical trials also have some important differences when compared to their therapeutic counterparts. For instance, when using the Phase 1/2/3 paradigm in the setting of imaging trials, Phase 1 imaging trials more often investigate questions such as feasibility and bio-distribution rather than dose finding and determining the maximum tolerated dose in terms of toxicity. Phase 2 and Phase 3 imaging trials investigate preliminary efficacy and efficacy against current standard of care methods, respectively. Another important difference is that details such as the imaging acquisition protocol, imaging analysis hardware and software, and interpretation guidelines are much more important to imaging trials compared to therapeutic trials, especially when quantitative imaging analysis is involved. Because of these issues, there is a far greater need for standardization of the various components in an imaging clinical trial compared to therapeutic trials. The promotion and assistance in the effort to create imaging standards and guidelines is one of the goals of the Cancer Imaging Program.