Nuclear Cardiology Radiation Exposure Practices | Journal Scan
What is the radiation exposure of patients undergoing nuclear myocardial perfusion imaging (MPI), and is this affected by laboratory use of “best practices”?
An observational cross-sectional study was conducted of protocols used for all 7,911 MPI studies performed in 308 nuclear cardiology laboratories in 65 countries for a single week in March–April 2013. An expert committee a priori identified eight “best practices” relating to radiation exposure, and a radiation-related quality index was devised that indicated the number of best practices used by a laboratory.
Patient radiation effective dose (ED) ranged between 0.8 and 35.6 mSv (median 10.0 mSv). Average laboratory ED ranged from 2.2 to 24.4 mSv (median 10.4 mSv); only 91 (30%) laboratories achieved the median ED ≤9 mSv recommended by guidelines. Laboratory quality indices ranged from 2 to 8 (median 5). Both ED and quality index differed significantly between laboratories, countries, and world regions. The lowest median ED (8.0 mSv), in Europe, coincided with high best-practice adherence (mean laboratory quality index 6.2). The highest doses (median 12.1 mSv) and low quality index (4.9) occurred in Latin America. In hierarchical regression models, patients undergoing MPI at laboratories following more “best practices” had lower EDs.
Marked worldwide variation exists in radiation safety practices pertaining to MPI, with targeted EDs currently achieved in a minority of laboratories. The significant relationship between best-practice implementation and lower doses indicates numerous global opportunities to reduce radiation exposure from MPI.
About 15-20 million MPI tests are performed worldwide each year; there is concern regarding radiation-related cancer risk associated with cardiac imaging in general, and MPI in particular. This study provides important data reflecting the worldwide adoption of strategies to reduce radiation exposure. The use of eight ’best practices’ (avoid thallium stress, avoid dual isotopes, avoid too much technetium, avoid too much thallium, perform stress-only imaging, use camera-based dose-reduction strategies, use weight-based dosing for technetium, and avoid inappropriate dosing that can lead to ‘shine through’ artifact) was quite variable, but associated with lower radiation doses. In this survey, European laboratories were most likely to achieve median effective dose ≤9 mSv (51% of laboratories), followed by African laboratories (42%); with the worst noted in laboratories in Oceana (21%), North America (20%), Asia (17%), and Latin America (11%).
Keywords: Angina, Stable, Artifacts, Cross-Sectional Studies, Diagnostic Imaging, Isotopes, Myocardial Perfusion Imaging, Neoplasms, Radiation-Induced, Quality of Health Care, Radiation, Radiation Dosage, Technetium, Thallium
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