This is an excellent document, one of the best ever produced by the ICRP. It conveys the principles of radiation protection to the medical community using a terminology with which health professionals are familiar with and thus can easily comprehend. It is unfortunate that some of the very clear and unambiguous statements in this draft have not been transferred verbatim to the draft of the New ICRP Recommendations.
Specific observations follow.
The Use of Effective Dose
In Sections 4 and 5.6, this document states that effective dose is not appropriate for planned medical exposures, given that the tissue weighting factor used in the derivation of effective dose are dependent on age and gender. Section 4 states: “The age distributions for workers and the general population (for which the effective dose is derived) can be quite different from that of the overall age distribution for the population undergoing medical procedures using ionizing radiation, and will also differ from one medical procedure to another depending on the age-and sex-prevalence of the individuals for the medical condition being evaluated”. Section 5.6 adds: “Effective dose can be of value for comparing doses from different diagnostic procedures and for comparing the use of similar technologies and procedures in different hospitals and countries as well as the use of different technologies for the same medical examination, provided the reference patient or patient populations are similar with regard to age and sex. As noted in Section 4, for planning the exposure of patients and risk-benefit assessments, the equivalent dose or the absorbed dose to irradiated tissues is the relevant quantity”. Unfortunately, the last sentence did not make it to the New ICRP Recommendations, giving there the impression that it is OK to use effective dose, when in reality the Radiation Protection in Medicine draft recommends the use of equivalent dose or absorbed dose to the irradiated tissue. If at all possible, the wording in this document should be the one used in the New ICRP Recommendations.
Overdosage in Radiation Oncology
The last sentence under 5.7 dealing with tissue reactions in radiation oncology states that “usually overdosage in excess of 10 percent will result in an unacceptably high risk of severe fatal complications”. The figure appeared for the first time in Publication 86, where no reference was given. The number seems arbitrary, especially since it does not specify the volume and the time involved. The figure needs a bibliographic reference.
The Justification of a Defined Radiological Procedure
Although it is well intended, the example given in the second paragraph will convey to the responsible parties in public medical facilities the idea that it is OK to use chest fluoroscopy to diagnose pulmonary diseases and that there is no need to get chest radiography. The example should be replaced by a less controversial one.
Radiological Protection in Emergency Medical Situations with Radioactive Materials
The wording in the second paragraph needs editing. The sentence “does not constitute medical intervention” does not make sense.
Exposures of Volunteers in Biomedical Research
Children as potential research subjects are not considered. The ICRP should provide guidance on this important issue.
Diagnostic Reference Levels
The historical review given in 13.1 and 13.2 is unnecessary. The current publication should consolidate the guidelines provided in the previous two publications and create one unique set of updated recommendations. The measurable quantities to be used for diagnostic reference levels should be those espoused by ICRU 74.
Section 13.2 introduces the term “authorised bodies”. Authorized by whom? By the Regulatory Authority (now termed Regulatory Body)? Section13.1 indicates that diagnostic reference levels are to be “set up by medical bodies”; in 13.2, “authorised bodies” are the ones to “use” them (7th paragraph) and “are encouraged to set” them (last paragraph). It would seem that the diagnostic reference levels should be used by anyone involved in diagnostic radiology without requiring any authorization. This discrepancy needs to be clarified. The New ICRP Recommendations in 7.2.1 state that: “The values should be selected by professional medical bodies (in conjunction with national health and radiological protection authorities)…”. The recommendations should be made consistent between the two documents. Ideally, the professional medical bodies should set the values and the governmental bodies should enforce their use.
Section 17 introduces the term “appropriate authoritative or professional body”. Who decides that the body is appropriate? Or authoritative? And are these professional bodies different from the medical bodies mentioned in previous sections? The terminology should be clarified and made consistent throughout the document.
Summaries of Previous ICRP Publications on Medical Exposures
The summaries of Publications 84, 85, 86, 87, 93, 94, 97 and 98 presented in Sections 17.1 to 17.9 detract from what is otherwise an excellent publication. Unfortunately not all the ICRP publications are of the same quality, and some should be updated in light of new technological advances (like 87 already is) and also to be aligned with the new ICRP Recommendations. The summaries should be deleted as they dilute the important message conveyed in the text of the document by focusing on details.
If the decision by the Commission is to keep them, the text needs language editing. For example 17.9 states that “the cremation of bodies (frequent in some countries)”… After repeatedly referring throughout the text to “authorised bodies” (hopefully no government plans to cremate any) the choice of words is amusing… In this context, the term “bodies” should be replaced by “cadavers”...