Who can participate in an imaging clinical trial?

Each study’s protocol has guidelines for who can or cannot participate in the study. These guidelines, called eligibility criteria, describe characteristics that must be shared by all participants. The criteria differ from study to study. They may include age, gender, medical history, and current health status. Eligibility criteria in an imaging trial may differ as compared to a treatment trial. Some examples of how imaging clinical trials might have special eligibility requirements follow:

• For screening trials, family history and lifestyle might be factors in determining eligibility. For example, a researcher might be trying to find an answer to the question "Is the new technique of digital mammography more or less effective at finding breast cancer than traditional film mammography in women that have a family history of breast cancer?" For this study, researchers would be looking for women who have a family history of breast cancer, but have not had suspicious mammograms or lumps previously.
• For diagnostic trials, eligible participants might have a suspicious lump or symptoms, be newly diagnosed with the type of cancer being studied, and not have received any type of treatment. For instance, a trial might compare a traditional diagnostic technique, such as a CT scan, with a diagnostic technique such as PET or MRI to see if they are as accurate or if they can provide new, valuable information.
• Imaging trials are sometimes part of other trials, such as drug treatment trials. In order to participate in such an imaging clinical trial, a treatment procedure would have to be followed. One example might be a trial using imaging to see if the blood supply to a tumor is reduced by a particular drug, which may slow or stop tumor growth. Participants in the imaging trial would need to meet the eligibility requirements and be enrolled in the treatment part of the trial.