Heartbeat: Staying safe with skin dosimetry
October 25, 2021
Our imaging team lead the way when it comes to providing a patient-focused service. They offer a full diagnostic service using X-ray, Ultrasound, MRI, DEXA and CT scanning machines, nuclear medicine and radiopharmacy. To ensure our services remain as safe as possible, we continually take steps to stay compliant with the latest safety regulations.
Anyone working with radiation needs to meet the Health and Safety Executive (HSE) criteria of competence and have the necessary experience and expertise to allow the safe use of ionising radiation.
Dr Bill Thomson recently retired Head of Physics and Nuclear Medicine, presented a paper at the National Radiation Protection Advisers meeting. This allowed for discussion on radiation protection topics of interest and regulators, HSE attended.
Speaking to Heartbeat, Bill remarked: “My topic for this meeting was new modelling of skin dosimetry from accidents in nuclear medicine. This dosimetry forms the basis for required HSE radiation risk assessments. Fortunately, accidents are quite rare, but if any radiopharmaceutical lands on the skin or hands in an accident, skin doses can be very highs. Having accurate models of skin contamination becomes important.
“I have supported with dosimetry calculations where the annual skin dose was exceeded, requiring HSE input. I have also been developing models of droplets landing on skin or gloves in an accident, and also modelling the retention on direct skin contamination. Needle stick injury with a radioactive tracer is another area I have modelled.
“Normal skin doses tend to relate to handling and dispensing procedures, particularly in radiopharmacy. We monitor colleagues with finger doses at their fingertips. We can then ensure that all fingertip skin doses are well below the annual limits.
“I have been using and promoting the use of a dedicated software program developed by the U.S. Nuclear Regulatory Commission. This involves developing models of droplets on the skin and gloves. Any accident can involve radioactive droplets, e.g. from a syringe during dispensing. I have been presenting this work to promote staff awareness of the high skin doses that can result from droplets on skin, and help with wider data of the doses involved.”
Dr Thomson added: “We have also enhanced our PPE to ensure all bare skin is covered during dispensing and injection procedures. Other departments are now doing the same – being ‘bare below the elbow’ cannot apply for those processes.”