Radiation protection of patients in diagnostic and interventional radiology
Introduction
Medical exposures are by far the dominant source of population exposure from artificial radiation sources and its utilization continues to increase worldwide, especially as new technologies become more disseminated. As per United Nations Scientific Committee on Effects of Atomic Radiation (UNSCEAR), 3.6 billion medical diagnostic examinations are currently performed globally each year with increase of 50% in the last two decades. Although there have been common principles of different imaging modalities, radiation dose from various examination can vary up to factor 100 or more. Specific actions must be taken to minimize risk to the patient by eliminating any radiation exposure that is not required for clinical objective.
Important Principles
Exposure to ionizing radiation from diagnostic X ray procedures is always voluntary. However, with respect to associated radiation risks, an international framework has been established to ensure a better understanding of radiation protection requirements and improve safety of patients. Professionals should be made aware of their responsibilities on the overall patient protection and safety in the prescription of and during the delivery of medical exposure. Justification and optimization are two of the cornerstones of radiation protection in medical exposures (see optimization), as dose limits do not apply to exposure of patients. As per safety standards, all diagnostic X ray examinations shall be justified in terms of clinical benefits and associated radiation risks and examination shall be performed only if benefit outweighs the risk. Once justified, examination should be performed in a way that provides required diagnostic information with minimal possible dose to patient. Although there are some common principles of protection that apply to all X ray imaging procedures, many of the most significant issues and actions are related to the specific modality used. The use of justification and optimization is most impotent in high dose procedures and computed tomography and interventional procedures and for special population groups as children and female patients of reproductive capacity.
Important references
The Radiation Protection of Patients (RPoP) website contains information to help health professionals achieve safer use of radiation in medicine for the benefit of patients. Radiation protection of patients in conventional and digital radiography, fluoroscopy, mammography, computed tomography and international radiology are all included as topics on the RPoP website. The website also contains training material on radiation protection in diagnostic and interventional radiology. As interventional cardiologists are among the most intensive users of X rays nowadays, an important section on the RPoP website and suitable training material is devoted to radiation protection in interventional cardiology. Also, useful information on use of X ray outside the radiology department, in other specialties that utilise X rays as dentistry, bone mineral densitometry, orthopaedic surgery, urology and gastroenterology are provided. Pregnant women and children form specific group for radiation protection purpose and they are dealt with separately.
Since radiation protection of staff is important in interventional procedures and in PET/CT, there is guidance available on the website in corresponding pages in addition to page on radiation protection of workers and public on this website.
The key standards in this area are the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources, also known as the International BSS. These standards mark the culmination of efforts that have continued over the past several decades towards the harmonization of radiation protection and safety standards internationally. Safety report to guide users in applying safety standards in radiology and other specialized areas are available for free download.