Abstract
2069
Objectives: Radiology is home to two types of radiation: radiation from machines which is governed by the Occupational Safety and Health Administration (OSHA), and radiation from radionuclides which is governed by the Nuclear Regulatory Committee (NRC). Yttrium-90 therapies expose interventional radiology (IR) physicians to both radionuclide and machine-based radiation. Dosimeters cannot differentiate between these two types of exposures, so issues may arise with deciding which governing body takes precedence regarding exposure limits. In addition to machine-based radiation exposure and radionuclide exposure, many IR physicians are employed by multiple institutions who use different companies to monitor their radiation exposure. Another issue lies in the fact that OSHA and the NRC use different standards to create exposure limits; OSHA has quarterly limits and the NRC has annual limits. There are also no set guidelines regarding how to systematically collect cumulative exposure data from different institutions and who takes precedence when overexposure occurs with both types of radiation. The purpose of this study is to provide education on the gaps currently present in IR radiation monitoring due to Yttrium-90 therapies.
Methods: OSHA and NRC guidelines were reviewed to determine exposure limits for each type of radiation. In addition, a survey was sent to radiation safety officers at 50 different academic, private and Veteran’s Affairs institutions in the US regarding radiation safety in IR and each institution’s protocol regarding staff dosimetry reports. An IR physician was interviewed who covers 2 facilities and the dosimetry data for this individual is still being accrued to determine whether the physician remained within OSHA and NRC guidelines when combining exposure across institutions.
Results: The NRC’s exposure limits for radiation workers is 5 rem total dose equivalent per year. OSHA’s occupational prospective dose exposure limits for machine-based radiation dose is 5 rem per year monitored quarterly with exceptions to overexposures based on lifetime exposures. 70% (35/50) of survey respondents indicated they request dosimetry reports for employees who are currently working at multiple institutions. There is currently no legal requirement for physicians to allow the institutions to release their dosimetry records to the other institutions in which they are employed.
Conclusions: Currently, there are radiation safety officers requesting dosimetry records for their employees who work in multiple institutions, but there are no set guidelines requiring this action. It is in the IR physician’s best interest to draw attention to their combined exposure rates. Development of policies by institutions and/or regulatory bodies may need to be explored. These policies may address the different types of radiation and capture the accumulation of radiation exposure at multiple institutions. 10% of maximum permissible radiation dose is cause for warning according to most institutions protocol that is based on as low as reasonably achievable (ALARA). Institution policies that are aimed toward keeping radiation burden within ALARA reinforces the point that total exposure for each physician should be reviewed.