29. October 2010 15:03
Clinicians who deliver radiation to the brain and heart should minimise their patients' exposure while maintaining essential medical benefits, according to advice from the Health Protection Agency (HPA).
The HPA's Advisory Group on Ionising Radiation (AGIR) has reviewed recent studies on the risks of circulatory disease following exposure to ionising radiation.
AGIR recommends that clinicians who use radiation for therapeutic or diagnostic purposes should keep doses to patients' brains and hearts as low as possible. It also emphasises the need for further study of risks to patients.
Professor Bryn Bridges, Chairman of AGIR, said: "High radiation doses are known to have effects on the heart. What is less clear is the magnitude of risk at the low dose levels commonly of concern in the protection of nuclear workers, the public and patients.
"Our report found evidence of risk down to around 0.5 Gray. Below that dose, interpretation is hindered by inadequate control of major lifestyle factors associated with heart disease. Furthermore, our understanding of the ways in which radiation might cause circulatory disease is too poor to justify the extrapolation of information obtained using high doses to the estimation of possible risk at low doses."
Dr John Cooper, director of the HPA's Centre for Radiation, Chemicals and Environmental Hazards, said: "It is reassuring that the committee was largely satisfied about present practices in relation to patient safety, radiation exposure and circulatory disease risk and recommends that clinicians working in this field should continue to maintain and spread best practice and where possible keep up with technical developments that reduce exposure of the brain, heart and blood system."
The HPA is now setting up a research programme into the role of radiation in causing cardiovascular disease.