Radiological protection in medicine

Draft document: Radiological protection in medicine
Submitted by Alexander Lebedev, Russian Scientific Centre of X-ray Radiology
Commenting on behalf of the organisation

Remarks to Radiological Protection in Medicine The project summarizes modern concepts of radiation influence on a person based on the accepted classification: - Deterministic Effects; - Stochastic Effects; - Effects of In Utero Irradiation. All the specified effects and the risks caused by them are based on a representation of radiation carcinogenesis as a unique stochastic evidence of radiation influence realities. We suppose that at the actual biology and mathematics development level another approach to estimation of radiation influence can be acceptable, especially in small doses. Particularly, the mathematical model based on the theory of image recognition and cluster analysis is developed. It allows to carry out multipurpose (multi-parametric) researches of organism and its systems health state, starting with dose 1 mSv and above. There were used the parameters of peripheral blood (from 9 up to 16 parameters), the immunological parameters (from 17 up to 24) and the digital parameters of urine as a multipurpose system. The obtained data are widely published in monographs and a number of articles in leading scientific journals In Russia. The received information concerning organism and its systems state changing allows us to judge: - negative effect of small doses exposure; - terms of restoration after exposure; - individual sensitivity of people under radiation exposure. The system also allows to take appropriate restoration measures after small dose exposure. It is necessary to note, that in a number of oncological clinics of Russia (Russian Scientific Centre of X-ray Radiology, All-Russian Oncological Scientific Centre and others) the organism and its systems health state estimation program (“ACS ENOFIT” software) is widely used for the treatment efficiency control of oncological diseases, giving a dynamic curve of organism and its systems health state change during the treatment. Thus, it is necessary to consider, that now it is essential to use not only statistical methods of great population groups processing exposed to the radiation leading to carcinogenesis, but also to carry out the health state change control of organism and its systems exposed to the unitary or prolonged small dose of radiation. From our point of view it is also necessary to pay attention to two moments, stated in the project. 1. In section 4 (p. 11) it is specified, that the basic dosimetric quantity is average value of the absorbed dose. Carrying out an estimation of biological effects of a nonuniform irradiation, for example, medical radiology, etc., apparently it is necessary to speak not about averages, but about modal values of the absorbed doses. It is obvious from representation about radiobiological effect which degree depends on number of the damaged cells. 2. Carrying out mass radiological researches (about 100 % of the population are subject to doubling of super-background irradiation of the person) at which the nonuniform irradiation of the person takes place it is necessary to leave test levels of effective doses for different categories of the population exposed. For example, in our opinion it is necessary to allocate three categories of the population for which test levels of doses are certain: - the persons, exposed preventive, dental and preventive mammography (annually) - the test level of an effective dose 1,5-2 mSv; - the persons, exposed to radiological researches for an establishment of the diagnosis of disease - the test level of effective dose 15 mSv; - the persons who are passing repeating researches during treatment, suffering heavy oncological diseases, a tuberculosis or heavy traumatized - the test level of effective doses - 150 mSv. The chosen test levels (1,5-2 mSv, 15 mSv and 150 mSv) consider modern facilities of medical radiology (digital fluorograph, mammograph, radiological diagnostic devices, computer tomographs, etc.) and the possibility (as for the first and second groups) of carrying out various researches or probability of repeating researches for patients of the third group. R. Stavitskiy A. Lebedev D. Lobov