Dear ICRP,
The ISRRT welcomes the opportunity to comment and give feedback on the draft ICRP report ‘The Use of Effective Dose as a Radiological Protection Quantity’
As the global stakeholder representing the radiographer/technologist community with over 500,000 members we believe that radiographers play a vital role in radiation protection and therefore welcome the report which gives greater clarity on the use of ‘Effective dose’ in the context of radiological protection.
The following is a summary of the comments and suggestions from colleagues: -
We think in general that the report is very good and will serve its purpose, but it should probably be followed up by more user-friendly information and examples. As it is known it is too much to read and too detailed to be used in clinical practise.
I would suggest making digital leaflets focusing on the most usual clinical situations were effective dose can be a valuable tool.
I would emphasize highlighting examples that can prevent wrong use of effective dose comparisons, like uncritically comparing doses with different field sizes, patient sex, genetics, and age.
What we need in the medical use of radiation are the examples that can help the practitioners (radiographers and radiologists) justify and optimize examinations and the referrals to make the correct judgements before referring. Also, the patients’ GPs/referrals need to have good examples that can help them inform (and calm) their patients that find out after being x-rayed that they wore pregnant after all.
Today there are GPs (and other health personnel) that actually recommend abortions even when there is a very low risk of radiation caused damage to the foster/unborn child. As you know there actually must be extreme high dose before an expert in this field actually recommend doing an abortion after having an x-ray exam. This fact should be explained better in the report in my opinion.
we would also stress the fact that effective dose comparing different kind of radiation is using several weight factors that are very uncertain, like the DRREF. The DRREF is used to reduce the risk when comparing for example the atomic bombings of Hiroshima and Nagasaki with medical radiation with photons, this due to lower dose rate in photons than in particles and neutrons. But the factor used is 50% reduction for both radon and for x-ray exposures. A reduction is most likely correct, but the factor seems much like “think of a number” and cannot be much researched based. Using same reduction for radon and photons seem a bit strange since the dose rate is much higher for photons than for radon.
Low effective dose value can also be misleading, for example when small field size is used. Small field size with high organ dose can cause stochastic effects, but the effective dose value may still be low. This could be highlighted better I think.
Effective dose should be used very carefully especially when the field sizes are small. There are also important organs that still don’t have a weight factor, like the heart. The heart is still radiation sensitive though, but some CT vendors are using the lack of weight factor to show low effective dose to the heart with their CT scanner/angio system. Hopefully there will come a weight factor also for the heart, there are probably relations between coronary disease and amount of radiation.
Other specific observations and comments include: -
1. Page 45/ justification of procedures lines 1680 “third level of justification”. Suggest that in addition to referring clinicians and radiologists that ‘authorised radiographers’ are included in the example as in many situations radiologists are not available.
2. page 45/ par 102 & 103/ lines 1695-1714 "Choice of technique".
These two paragraphs do not fall under the section 5.3 "Optimization and reporting of doses" (header on line 1694). My suggestion is that they move under section "5.2. Justification of procedures" (header on line 1668) under line 1693.
That way the radiographer/radiological technologist can and will justify his involvement in the justification of procedures as the sole health professional at the point of delivery capable to SELECT the most appropriate technique or method in relation to web-based decision tools (for referral) or to forward the referral to the radiologist when uncertain.
3. page 48/ par 115/ line 1828: "Examples of everyday exposures are those from natural background radiation and the dose that an individual might receive from cosmic rays during an airplane flight." could be substituted by: -
Examples of everyday exposures are those from natural background radiation, the dose that an individual might receive from cosmic rays during an airplane flight and the dose that an individual might receive during a chest X-ray." My reasoning is that since the chest x ray is the most common medical exposure with ionizing radiation, most patients and referring clinicians will be able to relate to and appreciate the connection.
We agree that the use of equivalent dose as a separate protection quantity should be discontinued to avoid confusion between this quantity and dose equivalent.
The ISRRT believes this draft on ‘The Use of Effective Dose as a Radiological Protection Quantity’ is essential to good practice for radiographers working with Interventional procedures.
We thank the ICRP for the opportunity to comment on the ICRP The Use of Effective Dose as a Radiological Protection Quantity report document.
Sincerely,
A. Stewart Whitley
Director of Professional Practice ISRRT
3.8.2018