Practical ways to reduce radiation dose for patients and staff during device implantations and electrophysiological procedures

The U.S. National Council on Radiation Protection and Measurements and United Nations Scientific Committee on Effects of Atomic Radiation each conducted respective assessments of all radiation sources in the United States and worldwide. The goal of this article is to summarize and combine the results of these two publicly available surveys and to compare the results with historical information. In the United States in 2006, about 377 million diagnostic and interventional radiologic examinations and 18 million nuclear medicine examinations were performed. The United States accounts for about 12% of radiologic procedures and about one-half of nuclear medicine procedures performed worldwide. In the United States, the frequency of diagnostic radiologic examinations has increased almost 10-fold (1950-2006). The U.S. per-capita annual effective dose from medical procedures has increased about sixfold (0.5 mSv [1980] to 3.0 mSv [2006]). Worldwide estimates for 2000-2007 indicate that 3.6 billion medical procedures with ionizing radiation (3.1 billion diagnostic radiologic, 0.5 billion dental, and 37 million nuclear medicine examinations) are performed annually. Worldwide, the average annual per-capita effective dose from medicine (about 0.6 mSv of the total 3.0 mSv received from all sources) has approximately doubled in the past 10-15 years. (c) RSNA, 2009.

Physicians performing interventional procedures are chronically exposed to ionizing radiation, which is known to pose increased cancer risks. We recently reported 9 cases of brain cancer in interventional cardiologists. Subsequently, we received 22 additional cases from around the world, comprising an expanded 31 case cohort. Data were transmitted to us during the past few months. For all cases, where possible, we endeavored to obtain the baseline data, including age, gender, tumor type, and side involved, specialty (cardiologist vs radiologist), and number of years in practice. These data were obtained from the medical records, interviews with patients, when possible, or with family members and/or colleagues. The present report documented brain and neck tumors occurring in 31 physicians: 23 interventional cardiologists, 2 electrophysiologists, and 6 interventional radiologists. All physicians had worked for prolonged periods (latency period 12 to 32 years, mean 23.5 ± 5.9) in active interventional practice with exposure to ionizing radiation in the catheterization laboratory. The tumors included 17 cases (55%) of glioblastoma multiforme (GBM), 2 astrocytomas (7%), and 5 meningiomas (16%). In 26 of 31 cases, data were available regarding the side of the brain involved. The malignancy was left sided in 22 (85%), midline in 1, and right sided in 3 operators. In conclusion, these results raise additional concerns regarding brain cancer developing in physicians performing interventional procedures. Given that the brain is relatively unprotected and the left side of the head is known to be more exposed to radiation than the right, these findings of disproportionate reports of left-sided tumors suggest the possibility of a causal relation to occupational radiation exposure.

The benefits of cardiac imaging are immense, and modern medicine requires the extensive and versatile use of a variety of cardiac imaging techniques. Cardiologists are responsible for a large part of the radiation exposures every person gets per year from all medical sources. Therefore, they have a particular responsibility to avoid unjustified and non-optimized use of radiation, but sometimes are imperfectly aware of the radiological dose of the examination they prescribe or practice. This position paper aims to summarize the current knowledge on radiation effective doses (and risks) related to cardiac imaging procedures. We have reviewed the literature on radiation doses, which can range from the equivalent of 1-60 milliSievert (mSv) around a reference dose average of 15 mSv (corresponding to 750 chest X-rays) for a percutaneous coronary intervention, a cardiac radiofrequency ablation, a multidetector coronary angiography, or a myocardial perfusion imaging scintigraphy. We provide a European perspective on the best way to play an active role in implementing into clinical practice the key principle of radiation protection that: 'each patient should get the right imaging exam, at the right time, with the right radiation dose'.