Diagnostic Reference Levels (DRLs) in radiography: theory, practical application to adult patients and dosimetric estimations

During the last decades, the technological development has interested the medical field too, leading to an enhancement in the quality of medical procedures. This improvement is partly due to the larger application of prevention, diagnosis and treatment practices based on ionizing radiations. Along with the increment of medical exposures to the population and the growing awareness of the possible side effects, it has arisen the natural need of introducing a regulation and standardization of these practices. Within this framework, it has been settled the concept of Diagnostic Reference Level (DRL). In this thesis work, which has been carried out at the Operative Unit (O.U.) of Medical Physics of IRCCS Azienda Ospedaliero-Universitaria di Bologna, we will focus on DRLs in radiography for adult patients, exposing the main theoretical aspects and showing some practical examples of their implementation. In particular, we will show the evaluation of compliance with DRLs for two x-ray rooms in the O.U. of Emergency Radiology, following both the previous normative (Italian D.Lgs. 187/00 [1]) and the new one, dated 2020 (Italian D.Lgs. 101/20 [2]). We will further elaborate these data by using PCXMC, a software based on the Monte Carlo method for the estimation of patient’s dose, and we will specifically compare the effective dose and some organ doses of chest antero-posterior and chest postero-anterior radiography. As result, we obtained that the practices considered comply with DRLs, and that, as expected, chest antero-posterior radiography tends to give a higher dose to the patient than chest postero-anterior.