reactor produced, the regulatory environment is primarily determined by the NRC, with Agreement States following suit. However, accelerator-produced nuclides are regulated by state law. The Department of Transportation sets packaging and labeling requirements for transport of therapeutic radionuclides.
The QM requirements of 10 CFR Part 35, as discussed above with regard to cobalt teletherapy, apply also to brachytherapy (and to therapeutic unsealed radionuclides, discussed below). No treatment may be delivered without a written directive from a physician named on the authorized user list of the facility license; the patient's identity must be confirmed by two independent means before administration; each administration must be carried out in accordance with the directive; and any unintended deviation (misadministration) from the written directive should be identified and reported to the NRC and to the patient, and corrective action should be taken.
The equipment and procedures for HDR remote after loading brachytherapy have been the subject of much regulatory interest. Several incidents of inadvertent patient overdose have been documented, one contributing to the death of a patient, as described in Chapter 1. The NRC recently has published a 60-page collection of current regulations, standards, and guidelines that apply to remote after loading brachytherapy (NRC, 1994). This document integrates statutory requirements of the NRC and FDA with standards and recommendations from international and national organizations such as the ACR, NCRP, American Association of Physicists in Medicine, American National Standards Institute, International Atomic Energy Agency, and National Institute of Standards and Technology.
In contrast to the smaller amount of radioactivity utilized in diagnostic nuclear medicine, larger amounts of radioactivity are intentionally chosen for use in therapeutic nuclear medicine. Therapy in nuclear medicine involves oral, intravenous, or intracavitary delivery of radionuclides in liquid form (sometimes called "unsealed" radionuclides). The radionuclide is chosen with the aim of ensuring that subsequent physiological redistribution will concentrate the radioactivity in the target tissue and, at the same time, reduce the radioactivity in surrounding normal tissues. Radionuclides suitable for use in therapeutic nuclear medicine must either localize in their elemental form (such as iodine uptake in the thyroid gland) or be bound to an appropriate pharmaceutical or antibody. A list of common nuclides used for therapeutic nuclear medicine is shown in Table 2.14.