Clinical Imaging Trials Basics

What are imaging clinical trials and why are they important?

Like other clinical trials, an imaging clinical trial is a research study involving volunteers. Each study aims to answer specific scientific questions to evaluate the effectiveness of imaging procedures in detecting, diagnosing, guiding, or monitoring the treatment of diseases. Participants in cancer-related imaging clinical trials contribute to advancing knowledge and making progress in the fight against cancer. For more information about clinical trials in general and how they work, see Learning About Clinical Trials.

For additional information about imaging techniques, see Cancer Imaging Basics, a visual introduction to cancer imaging, featuring information about imaging technologies and their uses.

For Patients

What are the types of imaging clinical trials?

There are several types of imaging clinical trials:

Screening imaging clinical trials generally ask questions that will help researchers learn what type of imaging test will best detect disease early, possibly before symptoms of the disease are noticed.
Diagnostic imaging clinical trials address questions about what type of imaging test will best detect disease when it is suspected or will help monitor known disease or monitor a therapy to evaluate whether it is working.
Image-guided interventional clinical trials evaluate the role of therapies that are directed by imaging techniques.

How are imaging clinical trials and drug treatment trials different?

Imaging clinical trials differ from drug treatment trials in that the scientific question being asked is aimed at understanding if or how a specific imaging test can best be used to screen, diagnose, direct the treatment of, or monitor the response to a therapy for a disease.

Who sponsors imaging clinical trials?

Clinical imaging trials are sponsored by private organizations, by companies that develop imaging devices and imaging agents so these can gain approval by the FDA, by individual researchers and medical institutions, and by the National Cancer Institute. All are seeking better ways to screen, diagnose, and direct the treatment of disease.

NCI is involved with the facilitation of clinical trials in imaging, including the following:

American College of Radiology Imaging Network (ACRIN): ACRIN is an international cooperative group sponsored by NCI’s Cancer Imaging Program (CIP) as well as philanthropies. Through clinical trials of diagnostic imaging and image-guided therapeutic technologies, ACRIN’s goal is to generate information that will lengthen and improve the quality of the lives of cancer patients. ACRIN’s clinical trials address both existing and emerging technologies as they apply to cancer screening, diagnosis, staging, imaging as a biomarker, and image-guided treatment.
CIP Early Phase Clinical Trials of Imaging Agents: The Cancer Imaging Program (CIP) has developed a contract-supported infrastructure to support Phase I (Safety) and Phase II (Preliminary Efficacy) clinical trials of promising imaging agents.
Cancer Therapy Evaluation Program (CTEP): NCI’s CTEP approves and monitors over 300 scientifically rigorous clinical trials proposed by the Cooperative Cancer Groups, testing new oncology drugs, or novel combinations of existing drug, surgical and radiation therapy strategies. A large portion of these trials include imaging as part of staging or monitoring the progress of therapies. CIP participates in the Cancer Therapy and Evaluation Program (CTEP) protocol reviews. This collaboration encourages the integration of advanced imaging technology in ongoing therapeutic clinical trials and greater emphasis on imaging findings as potential biomarkers, assuring that image data in clinical trials will be reliable for monitoring and predicting response to various therapies.

Where do imaging clinical trials take place?

Imaging clinical trials take place in doctor’s offices, cancer centers, other medical centers, community hospitals and clinics, and veterans’ and military hospitals in cities and towns across the United States and in other countries. Imaging clinical trials may include participants at one or two highly specialized centers, or they may involve hundreds of locations at the same time.

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.

What is informed consent?

Informed consent is a process by which people learn the important facts about a clinical trial to help them decide whether to participate. This process is used in every imaging clinical trial and in clinical trials in general. This information includes details about what is involved, such as the purpose of the study, the tests and other procedures used in the study, and the possible risks and benefits. In addition to talking to the doctor or nurse, people receive a written consent form explaining the study. People who agree to take part in the study are asked to sign the consent form. However, signing the form does not mean people must stay in the study. People can leave the study at any time - either before the study starts or at any time during the study or follow-up period.

The informed consent process continues throughout the study. If new benefits, risks, or side effects are discovered during the study, the researchers must inform the participants. They may be asked to sign new consent forms if they want to stay in the study.

You should feel free at any time to discuss questions or concerns with the doctors and nurses in charge of the study. To find out more about informed consent, go to Informed Consent.

Should I participate in an imaging clinical trial?

In any clinical trial, there are risks and benefits to consider when deciding whether or not to participate. To learn more about risks and benefits of clinical trials, go to Should I Take Part in a Clinical Trial?

Some factors that are specific to imaging trials you may wish to consider are:

Some imaging procedures may be uncomfortable, such as lying for a period of time in a magnetic resonance or CT scanner.
If two imaging techniques are being compared and you receive both, you might be subject to more X-rays or radioactive substances than if you did not participate in the trial. Having more than one test will take extra time although frequently there is added benefit from both tests.
Some studies may require injection of contrast agents that increase the ability of an imaging technique to tell the differences between tumors and normal cells. Injection of these agents may require an injection into a vein for access to the blood stream (an I.V.). The contrast agents could cause discomfort, or in rare instances an allergic reaction may occur.
Most trials cover the cost of the imaging procedures but in some circumstances health insurance may be relied upon. Your coverage may not include some or all of these costs. For more information on dealing with cost and coverage barriers, see the description of the specific trial as well as Clinical Trials and Insurance Coverage: A Resource Guide.

Finding an Imaging Clinical Trial

In addition to the resources described in the section titled "Who Sponsors Imaging Clinical Trials", people interested in taking part in an imaging clinical trial should talk to their health care provider. A number of imaging clinical trials are currently being conducted that use specialized equipment. These are being conducted at sites across the United States, Canada, and Europe. Location may be a factor to keep in mind when searching for a trial in which to participate.

Searching for Clinical Trials

NCI’s PDQ Clinical Trials Database contains approximately 2,000 open/active (accepting patients) clinical trials for cancer treatment, supportive care, genetics, prevention, screening, and diagnosis, including imaging clinical trials. In addition, there is access to approximately 13,000 abstracts of closed clinical trials that have been completed or are no longer accepting patients. Most abstracts are written in two formats, the health professional abstract (uses technical terminology) and the patient abstract (uses non-technical language).

View the clinical trials being conducted by the American College of Radiology Imaging Network (ACRIN), sponsored by NCI’s Cancer Imaging Program (CIP).

Help Finding Clinical Trials

Information about imaging clinical trials and clinical trials in general is available from the Cancer Information Service (CIS). Information specialists at the CIS use PDQ, the NCI’s cancer information database, to identify and provide detailed information about specific ongoing clinical trials.

Telephone

Talk with an information specialist from the NCI’s Cancer Information Service — within the United States, Monday through Friday 9:00 a.m. to 4:30 p.m. ET.

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Use this feature for a confidential online text chat with an NCI information specialist, Monday through Friday 9:00 a.m. to 10:00 p.m. U.S. Eastern Time.

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Additional Information about Clinical Trials

For more information and news about clinical trials, please visit the Clinical Trials area of NCI’s Web site.