Radiation Safety for Small Animal Practices
As veterinary professionals we are frequently involved in using x-rays to make radiographs of our patients for diagnostic purposes. The pressures of busy practice life can create an environment where we forget to prioritize our own safety during these procedures. Bearing in mind the triad of radiation safety principles, Time, Distance, and Shielding, and committing to an Attitude where personnel safety comes first, are important steps to ensure a healthy practice environment for all.
To apply the concepts of Time, Distance, Shielding, and Attitudes to your practice,consider these tips:
Time: Minimize the time that each team member is exposed to x-radiation.
The risks accompanying radiation exposure increase with the dose that you are exposed to. Therefore, it is important to minimize the time that you are exposed to radiation. The most effective way to achieve this is by never hand holding a patient for radiographs. This can be achieved through the use of positioning devices such as troughs, sand bags, tape, Velcro restraints, etc. When needed, sedation should be used to ensure patient compliance. A veterinary team member should only be involved in providing manual restraint when these options fail. In that instance, the principle of minimizing the time that an individual team member is exposed to radiation should still be paramount and can be achieved by ensuring appropriate radiographic technique to minimize retakes, only performing the necessary views, and rotating duties in radiology.
Distance: Maximize your distance from the x-ray machine and patient
The dose that you receive from being present during an x-ray exposure will be reduced the farther you are from the x-ray source. During radiography, excess x-rays are scattered in all directions from the patient. This means that anyone standing near the patient will be exposed to the highest amount of scatter radiation, while those farther away will be exposed to substantially less. While the most effective option is to stand behind an appropriate barrier or leave the room, those personnel who remain in the room should still make use of the distance principle to minimize their radiation exposure. This can be achieved by stepping as far away from the patient as possible, even if hand holding. Use of radiolucent devices such as wooden spoons/paddles, tape, or similar restraint devices can allow you to increase your distance from the x-ray scatter while still maintaining patient control. Suppose you are approximately 1 foot from a patient while holding for an x-ray exposure. Stepping back to 2 feet will reduce your exposure to harmful radiation by 4 times (this is known as the Inverse Square Law).
Shielding: Use appropriate personal protective equipment
The use of lead (or lead equivalent) shielding is mandatory during radiography. Lead gowns, gloves, thyroid collards, and goggles, are the most commonly available and should be used each time. These should be properly fitting and carefully maintained to prevent damage. Remember that this equipment is not designed to block the primary x-ray beam, only scattered x-rays. This means that even if you are wearing gloves, you must not have your hand or any part of your body in the primary x-ray beam path, as indicated by the collimation light on the x-ray tube. If you can see your lead gloves on the radiograph, this principle has been violated. Other types of shielding that can be useful include portable leaded glass screens which personnel may stand behind during an x-ray exposure. It is never appropriate to be present during an x-ray exposure without suitable personal protective equipment.
Attitudes: Commit to a safety first policy in your practice
Perhaps the most important component x-ray safety is fostering a work environment in which staff safety is a priority. The recommended attitude towards radiation exposure in veterinary workplaces is to keep staff exposure to radiation As Low As Reasonably Achievable, known by the mnemonic ALARA. When performing an x-ray procedure, each team member should strive to keep radiation exposure levels ALARA by applying the principles of minimizing Time, maximizing Distance, and utilizing Shielding.
About the Author
About Heather Chalmers, DVM, PhD, DACVR, Associate Professor of Radiology, OVC Dr. Chalmers is a radiologist at the Ontario Veterinary College with a special interest in radiation safety. Her current graduate student, Dr. Monica Jensen, is conducting a survey of Ontario veterinary professionals to gain a better understanding of their current safety practices. Look for us at the scil booth #603 in the exhibitors hall at the OVMA Conference!