January 10th, 2014
ESC Spotlights Growing Problem of Radiation Exposure in Cardiology
Both medical professionals and patients have a general sense that radiation used in medical imaging and procedures carries some danger, but they often underestimate the risk. And certainly most are unaware of the increasingly large proportion of the problem occurring during cardiology procedures.
“Cardiologists today are the true contemporary radiologists,” said Eugenio Picano, lead author of a report from the European Society of Cardiology published in the European Heart Journal. “Cardiology accounts for 40% of patient radiology exposure and equals more than 50 chest X-rays per person per year,” he said in a press release. And cardiologists themselves can be exposed to radiation at two to three times the levels of diagnostic radiologists, according to the report.
The major barrier to recognizing the problem, of course, is that it may take decades before cancers emerge as a result of the radiation. Further, the authors note, “radiation-induced cancer is clinically undistinguishable from a spontaneously occurring cancer.”
Many patients are exposed to high doses of radiation (>50 mSv) for which there is epidemiological evidence showing a link to cancer. The authors estimate that patients exposed to 100 mSv, which is equivalent to about 5000 chest x-rays, will have “an additional risk as high as 1 in 30 or as low as 1 in 300.”
Nuclear cardiologists can receive as much as 2-5 mSv a year while interventional cardiologists and electrophysiologists have an annual exposure of about 5 mSv, which is two to three times higher than the exposure of diagnostic radiologists. This exposure, they calculate, results in “a typical cumulative lifetime attributable risk on the order of magnitude of 1 cancer (fatal and non-fatal) per 100 exposed subjects.”
Children, of course, are at greatest risk, “because they have more rapidly dividing cells and a greater life expectancy.”
“Even in the best centers, and even when the income of doctors is not related to number of examinations performed, 30 to 50% of examinations are totally or partially inappropriate according to specialty recommendations,” said Picano, in the press release. “When examinations are appropriate, the dose is often not systematically audited and therefore not optimized, with values which are 2 to 10 times higher than the reference, expected dose.”