There is a new WHO report on risk communication in paediatric imaging (http://www.who.int/ionizing_radiation/pub_meet/radiation-risks-paediatric-imaging/en/) which I think is a useful contribution.
How should we engage with the public, inform them of the potential risks and benefits of radiation, explain our attempts to minimise radiation dose to our workers and the pubic in normal operation and in accident situations and ask for their informed support for our continued existence?
Maybe you’d write a document modelled on this one.
The medical profession is often accused of being behind the nuclear industry in terms of their attempts to reduce radiation dose to as low as reasonably achievable. This publication could go a long way to reverse that feeling and, in my opinion, represents a level of good practice ahead of the nuclear industry.
The premise of the document is that “Patients and families should be part of risk–benefit discussions about paediatric imaging so they can best understand the information and use it for making informed choices”.
However, the document is clearly not aimed at the public itself. This is evidenced by the opening to the introduction to radiation “Radiation is energy emitted in the form of waves or particles, transmitted through an intervening medium or space. Radiation with enough energy to remove electrons during its interaction with atoms is called “ionizing radiation””, which I suspect is unlikely to encourage anyone without some physics training to read further. What the document does do well is to marshal the arguments and data required for an informed discussion.
The report gives a review of medical procedures and their dose implications and shows how the use of ionising radiations has grown over the last few decades. It provides, with caveats, a table (table 4 of the report) which shows, for a number of procedures, the equivalent number of chest X-rays and the number of days natural background to give the same dose.
It also gives an overview of the health effects of ionising radiation exposure with a quick but useful explanation of deterministic effects, stochastic effects and latency. It states that “Given the current state of knowledge, and despite the uncertainties regarding the risks associated with multiple exposures/cumulative doses, even the low-level of radiation dose used in paediatric diagnostic imaging may result in a small increase in the risk of developing cancer in the future”. It labels this “Lifetime Attributable Risk” (LAR).
This risk is then compared to the Lifetime Baseline Risk (LBR) and graphs are presented that show that females are more susceptible to radiation harm than males and younger people more so than older.
The report suggests a qualitative approach to communication of fatal cancer risk (See below) and a similar one based on the risks of cancer induction. This shows not only the additional risk of cancer but also the total risk.
This then allows different procedures to be discussed using language understood by most people and using a risk assessment that is consistent and justified (See their Table 8, reproduced below).
It has a good section on the optimisation of dose for children during procedures – basically taking account of their smaller size generally allows lower doses to achieve the same resolution.
Section 2 of the report is a review of the principles of radiation protection, how they apply to paediatric medicine and how a radiation safety culture can be encouraged.
Section 3 is about the risk/benefit dialogue. This states that “A recent study that assessed patient knowledge and communication preferences has concluded that there is a substantial gap between patient expectations and current practices for providing information about ionizing radiation medical imaging” and that “A major goal of radiation risk communication in medicine is to ensure that patients, parents and/or caregivers receive the information they need in a way that they can understand”.
The report suggests that while experts see risk as a product of hazard, exposure and susceptibility the public have a more emotional response including fear, anger and outrage and shows how prepared and considered communication at all stages of the referral and exposure process can ease these emotions.
It compares two possible responses to a mother’s concern:
- “The CT that you had two weeks ago has perhaps doubled the risk that your child will develop cancer before age 19.” [0.6% vs 0.3%]; or
- “The CT was an important exam that allowed the physicians to rapidly evaluate and treat your injuries which otherwise could have placed your health and the health of your baby at risk. The risk of adverse outcome is very small and the likelihood of normal development is still nearly the same as it is for any child.” [96.7% vs 96.4%]
And cautions that: “When considering benefits and risks, there is an important risk that is quite often forgotten: the risk of not performing an exam that may result in missing a diagnosis and initiating treatment too late to improve the medical outcome. The potential to improve a patient’s life expectancy due to early diagnosis and treatment must be considered in comparison to the magnitude of the cancer risk and its latency compared to the age of the patient and other comorbidities”.
The report anticipates some of the questions that patients and their carers might ask and provides model answers. It also suggests prepared message maps as a process for collecting and collating evidence.
In summary, this report gives a competent review of the potential health effects of ionising radiation used in paediatric medical imaging and discusses how these doses can be kept as low a reasonably achievable by choosing low-dose options where available and by optimising the imaging conditions taking into account the size of the patient.
It provides the reader with a good review of the risks of ionising radiation and some valuable hints on when and how to communicate this to patient’s carers.
It goes a long way towards enabling an informed discussion leading to shared decisions and understanding about choices made in the care of children.
This 
Katmal Limited has now completed two years of operation. In that time we have worked for new build companies, a generation company, a nuclear dockyard, a decommissioning site and local authorities. Now looking forward to the next two years and looking for new customers.
IAEA Nuclear Energy Series No. NW-T-2.8