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Radiation Exposure Risk Statements: Examples

See how other investigators have explained radiation exposure risks for research protocols involving human subjects.

UCSD’s Radiation Risk Statement Calculator can provide much of the radiation exposure risk statement required for research protocols involving exposure of human subjects to ionizing radiation. However, unique situations may require the investigator to write a customized explanation of risks.

These examples illustrate how other investigators explained radiation risk exposure, ranging from an uncomplicated protocol to more challenging variations.

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Example 1: Uncomplicated protocol

This study requires the participant to have a baseline CT scan of the head and a chest x-ray. The CT of the head will be repeated at the end of 6 months and then again at the end of 12 months.

Suggested format for explanation:

During your participation in this research study, you will be exposed to radiation from scheduled x-rays and/or imaging scans. The total exposure resulting from these imaging studies is calculated to be approximately 15.2mSv. This amount is more than you would receive from one year of natural exposure in the San Diego area, which is approximately 1.6 mSv. Cumulative exposure from radiation may increase your risk of developing certain types of cancer in the future.

The principal investigator for this research study has determined and verified that all of the x-rays and/or imaging scans prescribed for this study would typically be performed as part of the standard medical care required to adequately monitor your current illness. If you are especially concerned with radiation exposure, or you have had a lot of x-rays or imaging scans already, you should discuss this with the principal investigator for this study, Dr. Principal Investigator, or your regular doctor.

How the investigator arrived at this explanation:

15.2 mSv comes from inputting 1 chest x-ray and 3 Head CTs into the UCSD Radiation Risk Statement Calculator. The Risk Statement Calculator generated the risk statement which can be copied and pasted directly into the appropriate sections of the protocol with the appropriate researcher adjusted statements. No additional explanations are required as all scenarios for this protocol have been addressed.

Example 2: Moderately complicated protocol

This study requires a fluoroscopic procedure (cardiac catheterization) be performed at the beginning of the study period. At the 9-month follow-up visit, the procedure may need to be repeated.

Suggested format for explanation:

During your participation in this research study, you will be exposed to radiation from scheduled x-rays and/or imaging scans. The total exposure resulting from these imaging studies is calculated to be approximately 4.4mSv. This amount is more than you would receive from one year of natural exposure in the San Diego area, which is approximately 1.6 mSv. Cumulative exposure from radiation may increase your risk of developing certain types of cancer in the future. There is a possibility a repeat angiogram will need to be performed at your 9-month follow-up visit. If this is necessary, you will be exposed to an additional 4.4 mSv of radiation. The total exposure with 2 angiograms is 8.8 mSv.

The principal investigator for this research study has determined and verified that all of the x-rays and/or imaging scans prescribed for this study would typically be performed as part of the standard medical care required to adequately monitor your current illness. If you are especially concerned with radiation exposure, or you have had a lot of x-rays or imaging scans already, you should discuss this with the principal investigator for this study, Dr. Principal Investigator, or your regular doctor.

How the investigator arrived at this explanation:

4.4 mSv comes from inputting 1 cardiac catheterization into the UCSD Radiation Risk Statement Calculator. 8.8 mSv is the total if 2 angiograms are required. The italic text was written by the investigator (not generated by the Risk Statement Calculator) to add clarity to the explanation.

Example 3: Complicated protocol

This protocol to evaluate a new drug therapy requires CT scans of the chest/ abdomen/ pelvis, a chest x-ray, and a PET scan at the time of entry into the study. The CT scans and the PET scan will be repeated at 3 months. At this time, some patients will be required to undergo radiation therapy. For these select patients, overall radiation exposure will increase dramatically.

Suggested format for explanation:

During your participation in this research study, you will be exposed to radiation from scheduled x-rays and/or imaging scans. The total exposure resulting from these imaging studies is calculated to be approximately 70.2mSv. This amount is more than you would receive from one year of natural exposure in the San Diego area, which is approximately 1.6 mSv. Cumulative exposure from radiation may increase your risk of developing certain types of cancer in the future.

The principal investigator for this research study has determined and verified that most of the x-rays and/or imaging scans prescribed for this study would typically be performed as part of the standard medical care required to adequately monitor your current illness. The initial chest x-ray and CT of your chest/abdomen /pelvis would be done even if you were not a participant in this research protocol. The additional CT scans and PET scans are for research purposes only. If you are especially concerned with radiation exposure, or you have had a lot of x-rays or imaging scans already, you should discuss this with the principal investigator for this study, Dr. Principal Investigator, or your regular doctor.

How the investigator arrived at this explanation:

70.2 mSv comes from inputting the initial CT scans (chest/abdomen/pelvis), chest x-ray, and PET scan, plus the follow up CT scans and PET scan into the UCSD Radiation Risk Statement Calculator. The italic text was written by the investigator (not generated by the Risk Statement Calculator) to add clarity to the explanation.

Note that the UCSD Radiation Risk Statement Calculator does not provide radiation exposure estimates for radiation therapy protocols. The explanation above is sufficient for the radiation exposure and risk discussion. The researcher should include in the consent form in a separate paragraph an extensive description of what the patient can expect when undergoing radiation therapy. This should include the prescribed dose of radiation and the possible side effects from the treatment. The italic text was written by the investigator (not generated by the Risk Statement Calculator) to add clarity to the explanation.

Example 4: Alternative example of a complicated protocol

An alternative example of how a complicated consent for a protocol may be written when there is a choice to use non ionizing radiation imaging modalities.

Note in this protocol alternative imaging modalities were available for the patient to have in lieu of those using radiation. Anytime imaging modalities using non ionizing radiation can be used instead of ones that use ionizing radiation, these should be described and mention of the reduction of radiation dose by using them should be included in the consent statement.

Suggested format for explanation:

Risks from X-rays and/or Scans: During your participation in this research study, you will be exposed to radiation from mammogram, CT, bone and MUGA scans. The exposure resulting from these imaging studies is calculated to be approximately 57.06 mSv the first year with a 10 year total of up to 189.03 mSv, depending on imaging selected. This amount is more than you would receive from one year of natural exposure in the San Diego area, which is approximately 1.6 mSv. You may be exposed to an additional 132.0 mSv if PET scans are used instead of bone scans. Cumulative exposure from radiation may increase your risk of developing certain types of cancer in the future.

The principal investigator for this research study has determined and verified that all of the x-rays and/or imaging scans prescribed for this study would typically be performed as part of the standard medical care required to adequately monitor your current illness. Radiation exposure may be decreased if non-radiation imaging alternatives are utilized, such as ECHO instead of MUGA and/or a MRI instead of a CT. If you are especially concerned with radiation exposure, or you have had a lot of x-rays or imaging scans already, you should discuss this with the principal investigator for this study, Dr. Principal Investigator, or your regular doctor.

How the investigator arrived at this explanation:

The investigator obtained the dose numbers from the UCSD Radiation Risk Statement Calculator. Because of the complexity of the study and choices available to the patient, the consent statement generated by the Risk Statement Calculator was modified by the researcher to summarize and explain to the patient the expected dose and available choices for reducing their radiation exposure. The italic text was written by the investigator (not generated by the Risk Statement Calculator) to add clarity to the explanation.

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Acknowledgment: The Radiation Risk Statement Calculator was made possible by the generous contribution of Robert E. Reiman, MSPH MD, Assistant Clinical Professor (Radiology) Faculty, Medical Physics Graduate Program, Radiation Safety Division, Duke University Medical Center.

This information and the UCSD Radiation Risk Statement Calculator are intended exclusively for UCSD employees and affiliates.