The benefits of cardiac imaging are immense, and
modern cardiac electrophysiology (EP) requires the extensive and versatile use
of a variety of cardiac imaging and radiology-based techniques. In the cardiac
electrophysiology lab, doses can range around a reference effective dose (ED)
of 15 milliSievert corresponding to 750 chest x-rays for a cardiac
radiofrequency ablation, ranging from less than 2 to > 60 mSv. The reference
dose for a regular pacemaker or ICD implant is 4 mSv (range 1.4-17) and for a CRT implant is 22 mSv (range 2.2-95). Doses on the order of magnitude of 10-100 milliSievert (mSv)
correspond to a low (albeit definite, not negligible) additional lifetime risk
of fatal and non-fatal cancer from between 1 in 1000 (10 mSv) to 1 in 100 (100
mSv). The increasing use and complexity of cardiac electrophysiology techniques
have not been matched by increasing awareness and knowledge by prescribers and
practitioners. The protection of doctors is just as important as protection of
patients. Most experienced (and most exposed) interventional cardiologists and
electrophysiologists have an exposure per annum of around 5 mSv, two to three
times higher than diagnostic radiologists, with a typical cumulative lifetime
attributable risk on the order of magnitude of 1 cancer (fatal and non-fatal)
per 100 exposed subjects. Operator dose per procedure correlates somewhat with
the patient dose, but may be typically 1000 times lower depending upon the
shielding employed (one unit of incidence scatter dose for the operator when
1000 units of incident dose are given to the patient). However, adequate
radiation protection training and diligent protection can reduce this radiation
exposure by 90%.
The priority given to radioprotection in every
cardiology department is an effective strategy for primary prevention of
cancer, a strong indicator of the quality of the cardiology division, and the
most effective shielding for enhancing the safety of patients, doctors, and
staff.
Credits: Eugenio Picano; Emanuela Piccaluga; Renato Padovani; Claudio Antonio Traino; Maria Grazia Andreassi; Giulio Guagliumi