Radiation protection in brachytherapy entails protecting members of the public, radiation professionals, and the patient from unnecessary radiation, as well as making sure that the radiation used in the patient’s treatment is placed correctly with the correct dose distribution. Protecting members of the public from radiation emanating from brachytherapy sources implanted in a patient was an issue several decades ago, but with modern brachytherapy, the problem has mostly disappeared. The most frequent treatments are either low-dose-rate permanent implants for prostate cancer, or high-dose-rate procedures for gynecological, breast, or skin cancers. Almost all current permanent implants use low-energy photon sources that are shielded by the patient. Similarly, some temporary implants, such as eye plaques that also use low-energy photon sources, incorporate a metallic shield into the applicator. All high-dose-rate brachytherapy takes place in a treatment vault, in a manner similar to external-beam radiotherapy, thus eliminating exposure to members of the public, in the absence of some terrible error or mistake. Modern brachytherapy techniques either eliminate or greatly reduce radiation exposures to the brachytherapy staff also. As noted above, high-dose-rate treatments take place in a heavily shielded vault, and staff remain outside the vault when the source is out of its shielded housing. For low-energy permanent implants, facilities often order the sources loaded into the implant needles by the vendor, reducing the time the procedure staff is exposed to the source. Often, the loaded needles can be shielded while awaiting implantation. Alternatively, individual sources may be placed using a special applicator that shields the staff. Radiation protection of the patient in many respects differs little from how it was decades ago except for greatly increased precision. Assaying the strength of a source of any kind is still essential. As important as verifying the source strength is ensuring that the source will be in the correct location for the desired time. Imaging serves as the main mechanism to guide the implantation and verify source or applicator position. Modern imaging has unveiled anatomy exquisitely and often permits definition of target disease and neighboring normal structures sufficiently to allow very conformal dose distributions. Despite these great advances and capabilities, errors and mistakes (together called failures) still occur. Failures in health care overall are the third leading cause of death in the United States. Most treatment failures result not from equipment problems but from procedures gone wrong. Attention to comprehensive commissioning of both equipment and procedures and risk-based development of quality management procedures helps protect the patient. Patient safety organizations, established by the Agency for Healthcare Research and Quality, work with client facilities to help identify weaknesses in both treatment procedures and quality management and to develop improvements to enhance protection.
1Department of Medical Physics, University of Wisconsin—Madison, 1005 Wisconsin Institutes for Medical Research, 1111 Highland Avenue, Madison, WI 53705.
The author declares no conflicts of interest.
For correspondence contact the author at the above address, or email at firstname.lastname@example.org.
(Manuscript accepted 23 September 2018)