September 29, 2006
The U.S. Nuclear Regulatory Commission (NRC) recently released Regulatory Issue Summary 2006-18 Requesting Exemption from the Public Dose Limits for Certain Caregivers of Hospital Patients (RIS-06-018), which provides guidance to licensees on the means they may use to obtain an exemption, on a situational basis, from the dose limits in 10 CFR 20.1301 for "caregivers" (family, friends, etc.) of patients.
The following text is from the background section of RIS-06-018 (.pdf file)...
Patients undergoing medical diagnostic or therapeutic procedures involving the use of radioactive materials may be released from the hospital, even though they represent sources of potential radiation exposure to members of the public, if they meet certain release criteria. These criteria are specified in 10 CFR 35.75. Patients who do not meet these release criteria must remain in the hospital until they do satisfy them. Aside from failure to meet release criteria, patients with administered or implanted radioactive materials may remain in the hospital for reasons such as ongoing diagnosis or treatment. Such patients are usually visited in the hospital by family and friends, and these visitors are considered members of the public, subject to the dose limit specified in 10 CFR 20.1301 for members of the public. This limit, normally 1 mSv (0.1 rem) per year, and in some cases 5 mSv (0.5 rem) per year, is easily observed for the vast majority of visitors.
In some cases, however, this dose limit is insufficient to accommodate situations in which a member of the public, who will be referred to in this RIS as a caregiver, is directly involved in the care of a patient containing radioactive material. Caregivers are usually members of the patient’s family, or someone close to the family or the patient. They do not include hospital staff, who are considered to be occupationally exposed individuals subject to occupational dose limits that are much higher than the limits for members of the public. The role of caregivers often involves close contact with the patient, sometimes for prolonged periods of time, with the result that the radiation doses they receive may be much higher than the dose limit that would normally apply to members of the public.
To address this situation, NRC staff proposed to the Commission that dose limits for caregivers be established on a case-by-case basis by the licensee, and that their doses be limited only by the demands of their care-giving functions and the needs of the patient, provided the dose not be permitted to be high enough to present an immediate danger to the health of the caregiver or to increase the potential long-term risks resulting from radiation exposure to unacceptable levels. The rationale behind this approach is that dose limits are normally imposed for the protection of persons who are exposed either involuntarily, as in the case of exposures to members of the public, or who are exposed as a result of their occupations, such as hospital staffs and others whose occupations necessarily involve exposure to radiation. The caregiver situation is different in that it involves a voluntary decision by the caregiver, with the approval of the attending medical staff, to incur radiation exposure, and its potential risks, as an incidental consequence of the need to perform the caregiving function in the interest of the patient. The justification for incurring the exposure is that it is beneficial, or possibly essential, to the wellbeing of the patient, and may therefore be considered an extension of the patient’s medical treatment.
The Commission approved the staff’s proposal, and directed that a graded approach be used in controlling doses to caregivers. This approach would initially approve a default limit that experience has indicated would be adequate for most caregiver situations, and the Commission recommended that this default limit be set at 20 mSv (2 rem). The limit may subsequently be increased if it proves too low for a particular case. This RIS provides guidance for NRC licensees who may encounter such caregiving situations at their facilities and who may wish to apply for exemption from the dose limits in 10 CFR 20.1301. Requesting this exemption is not different in any essential way from any other exemption request, except that the Commission has already approved it in principle, and its approval by the staff in a specific case only requires a determination that a valid caregiver situation exists and that adequate controls will be implemented once the exemption is granted.