Introduction

This guidance has been prepared by the Clinical Radiation Safety Committee (CRSCo) to help ensure a careful, complete, and timely review of research projects that include human use of ionizing radiation. CRSCo serves under California Department of Health Services regulations and Nuclear Regulatory Commission regulations as the Radiation Safety Committee for Stanford and Veterans Affairs Palo Alto Health Care System, and is also chartered by the Food and Drug Administration as a Radioactive Drug Research Committee. It meets quarterly.

Review and Approval

Health Physics reviews the application for completeness and accuracy. If, for an adult, the effective dose is less than or equal to 5000 mrem (to compare the effective dose to the annual radiation worker) and the organ equivalent dose is less than or equal to the value derived by dividing 5 rad by the associated weighting factor (see table below), the Health Physics RSO or designee can approve the application.  Additionally, if the drug is not FDA approved and is under an IND, it may be approved by the RSO or designee.

If the effective dose is greater than 5000 mrem or the organ equivalent dose is greater than the value derived by dividing 5 rad by the associated weighting factor (see table below), before the next CRSCo meeting by the Chairman or his designee, the Radiation Safety Officer (RSO) or his designee, and one physician faculty member, or be approved at the next CRSCo meeting.

Note: The approval levels listed below are for adults. For minors, approval levels are 10% of those listed above and in the table.

All of these approvals are reported to CRSCo at its next meeting; it can re-open and revise the approvals. If the proposal requires the approval of the Radioactive Drug Research Committee, CRSCo must review and approve the application at the next meeting. There are also organ dose limits associated with each category.

¹ W_T values are from ICRP Report 60, Table 2: gonads 0.20; red bone marrow 0.12; colon 0.12; lung 0.12; stomach 0.12; bladder 0.05; breast 0.05; liver 0.05; esophagus 0.05; thyroid 0.05; skin 0.01, bone surface 0.01; remainder 0.05.

² Radioactive Drug Research Committee proposals require full CRSCo approval. Dose limits: whole body, active blood-forming organs, lens and gonads 3 rem per study and 5 rem total; other organs 5 rem per study and 15 rem total. See 29 CFR 361.1.

Draft “Informed Consent Form” Language

To estimate risk associated with a specific procedure, CRSCo uses the dose calculation methodology established by the International Commission on Radiological Protection in Report 60, “1990 Recommendations of the International Commission on Radiological Protection.” Based on the whole body effective dose H and organ equivalent dose H_T, CRSCo has prepared different statements you may want to consider when developing your “Informed Consent Form.”

Suggested language for when total dose < 3 mSv (approved by CRSCo 6/7/23):

This research study involves exposure to radiation from _[2 chest x-rays]_. This radiation is in addition to what you may get as part of your regular medical care. The additional amount of radiation is comparable to the radiation exposure from natural sources like the sun, ground and water. The average yearly background effective dose in the United States is 3 mSv. The amount of additional radiation you will get by participating in this study will be <3 mSv effective dose (equivalent # of days of background radiation). This amount of radiation involves minimal risk and is necessary to obtain the research information desired.

Suggested language for when total dose >3 mSv and <50 mSv (approved by CRSCo 12/8/21):

This research study involves exposure to radiation from __[2 PET/CT _]_. __ . The additional amount of radiation exposure is about _____ mSv, which is approximately equal to ___% of the limit that radiation workers (for example, a hospital x-ray technician) are allowed to receive in one year. This additional amount of radiation involves minimal risk and is necessary to obtain the research information desired.

Suggested language for when total dose > 50 mSv (approved by CRSCo 6/7/23):

You will be exposed to radiation during this research. Your radiation exposure will be about _____ mSv. This amount of radiation has an estimated risk of fatal cancer of about ___ percent. If randomly selected members of the general population were exposed to the radiation exposure from this research, the extra lifetime risk of dying from fatal cancer is about __ in 1,000. Statistics represent averages and do not predict what is going to happen to you. They do not take into consideration individual risk factors including lifestyle (smoking, diet, exercise, etc), family history (genetics) or radiation exposure. The majority of cancers occur later in life and the average lifetime risk of dying from cancer is 20% (1 in 5).

¹ ICRP, 1991:7 0.05 fatal cancers per person-sievert for the entire population

Suggested language for Category II organ equivalent dose proposals:

You will be exposed to radiation during this research. The dose to your skin will be about X rads. This dose may result in temporary or permanent hair loss and possible skin changes or damage.

Policy on Human Subject Research Utilizing Ionizing Radiation at Facilities NOT Affiliated with Stanford

CRSCO will not approve any research protocols that utilize Ionizing Radiation on human subjects at facilities not affiliated with Stanford University, Stanford Hospital and Clinics, Lucille Packard Children’s Hospital and Clinics and VAPAHCS, since CRSCo has no oversight of the radiation safety aspects of these facilities.

For a research protocol involving Ionizing Radiation on human subjects at a facility not affiliated with Stanford and when the x-ray usage has been approved by that facilities official IRB (e.g UCSF), CRSCo should not be asked to reapprove such a protocol.

For more information on how to prepare on IRB protocol

If you have questions specific to your project, please contact Health Physics at (650) 723-3201.