Ionising radiation is used in medicine every day, benefitting millions of people around the world who are affected by various conditions. An important arsenal in the field of medical imaging is computed tomography (CT). Since its introduction in the 1970s, CT scans have helped physicians detect the onset of disease at an early stage, thus allowing them to provide effective and, oftentimes, life-saving treatments.
Yet, despite all its advantages, the use of a CT scan - if improperly administered - can have negative effects on patient's health. The average radiation dose of one CT scan equals roughly the amount of radiation needed for 500 chest x-rays. So when use of other, more benign imaging modalities that do not employ ionizing radiation could provide the same answers, a CT examination can result in an unnecessary radiation dose for the patient.
"As the use of CT has increased significantly over the past two decades, so has the need for detection of inappropriate usage and application of appropriateness criteria developed by professional bodies," explains Madan Rehani, a radiation safety specialist at the IAEA.
Protecting Children
The risk is even greater for children if one is exposed to radiation during childhood so special attention needs to be paid to radiation protection of children.
The IAEA has noted a number of reports from developed countries which show that the same scanning protocols used for adults are also applied to children, resulting in overly high radiation doses. "Our intention is to check whether this situation is also true in developing countries, as these children need our urgent attention," Dr. Rehani added.
Awareness on the lack of radiation protection in CT of children has risen in recent years. Today, a wide range of international organisations and scientific networks have banded together to work towards a global improvement of radiation protection in paediatric practice. The IAEA plays a unique role in this area by providing education, support and resources to radiology professionals worldwide, enabling them to implement change for improved safety in the field. The IAEA's Radiation Protection of Patients (RPOP) Unit, in particular, develops and coordinates projects in over 60 countries, providing training, quality assurance and funding for regional networks dealing with medical radiation protection.
An International Action Plan
The IAEA has also established an International Action Plan for Radiological Protection of Patients as part of its statutory obligation to establish standards for the protection of people against the harmful effects of ionizing radiation and the application of these standards. This project is being realized in cooperation with the World Health Organization, the Pan American Health Organisation as well as United Nations Scientific Committee on the Effect of Atomic Radiation, to name a few organizations.
During a two- year study, IAEA scientists conducted a survey in 40 developing countries aimed at assessing the frequency of paediatric CT and the level of appropriateness of its use. The survey, conducted in Asian, Eastern and Central European, African and Latin American countries showed that the frequency of CT examinations of children was lowest in Europe and twice as high in Africa and Asia. The results revealed that there is a dramatic increase in paediatric CT examinations and that official guidelines are not followed in four of seven clinical situations with written referral guidelines oftentimes missing. Exposure factors as applicable for adults were also noticed being employed for children in some facilities.
"This is the first ever multinational study conducted in so many developing countries, assessing the level of usage and inappropriate usage of paediatric CT," Dr. Rehani concluded. The information obtained in this study will serve as a stepping stone for the implementation of guidelines needed to reduce the number of unnecessary CT examinations in children.
The results of the study have been published in May issue of the American Journal of Roentegenology.