The American College of Cardiology (ACC), Heart Rhythm Society (HRS), North American Society for Cardiovascular Imaging (NASCI), Society for Cardiovascular Angiography and Interventions (SCAI), and the Society for Computed Tomography (SCCT) have published, in the Journal of the American College of Cardiology, an expert consensus document on the optimal use of ionising radiation. Lead author John W Hirshfeld (Cardiovascular Medicine Division, Hospital of the University of Pennsylvania, Philadelphia, USA) speaks to Cardiovascular News about why there is need for such a document and its key recommendations.
On the whole, do you think cath lab staff are sufficiently aware of the dangers of radiation exposure?
I think that the levels of understanding and awareness are heterogeneous. There are some physicians who know this knowledge base and apply it well; others are less well informed. Awareness of the dangers of radiation exposure are similarly heterogeneous among cath lab nursing and technical staff—most do not hold a detailed knowledge base and take it on faith that their work environment and practices are safe.
Why was there a need to produce the consensus document?
ACC leadership felt that it was important to develop a document that would have educational value for its membership. There was concern that there is a growing use of radiation in cardiovascular procedures and that, as already discussed, the heterogeneity of understanding of the radiation knowledge base has led to increasing use without any consideration for the potential consequences to both patients and occupationally exposed medical staff.
Therefore, the ACC leadership wanted to create a document that brought together all of the relevant knowledge about radiation physics, biology, protection and equipment operation. They wanted a document written specifically for clinicians that would be both rigorous and accessible to cardiovascular practitioners.
We hope that it will be read by all cardiovascular specialists and that it will inform both how they conduct radiation-based procedures and how they select procedures for their patients.
The Writing Committee of the document was multidisciplinary. Why was it important to have a multidisciplinary team?
We wanted all constituencies to be represented, including patients. This includes both physicians who perform procedures and physicians who do not perform but order them for their patients; the decision to order a procedure is a decision to expose a patient to a given quantity of radiation—such decisions need to be informed by the knowledge base included in our document.
What are the key recommendations for reducing exposure to patients?
- Only use a radiation-based procedure when it is the optimal procedure to achieve the clinical purpose
- Consider the patient’s characteristics (intrinsic radiation-based risk, including patient age, gender, prior radiation exposure, comorbidities and natural life expectancy) as part of the decision to order a radiation-based procedure.
- Conduct a radiation-based procedure in a manner that employs the minimum amount of radiation needed. This requires optimal equipment quality and calibration and optimal selection of imaging protocols.
What are the key recommendations for reducing exposure to cath lab staff?
- The inverse square law is the best protection. Everyone should be as far as possible from the radiation source when it is on
- Minimising patient exposure also minimises exposure to occupationally exposed staff. What is good for the patient is good for you and your staff also
- Employ shielding optimally
- Make sure that your equipment is as up to date as possible and is calibrated to use the smallest amount of radiation that produces adequate images
- Know how to select imaging protocols that use the least radiation (including minimising exposed field sizes).
What key aspects of any training programme on radiation exposure cover?
- The basics of radiation physics
- The basics of radiation biology
- The radiation dose-risk knowledge base
- The engineering and theory of operation of radiologic equipment
- How to calibrate and use your equipment in the most dose-effective manner.