Design of lung shields for Total Body Irradiation (T.B.I) treatment.

This thesis focuses on the critical analysis of lung shields used in total body irradiation, examining their imperfections and criticalities in previous versions. The need to improve such shielding has been catalyzed by the ongoing changes in the set-up for total body Irradiation treatments in the medical physics department of the Marche university hospital. In response to these needs, new lung shielding has been introduced through a three-dimensional (3D) approach based on CT images of patients. These new shields, positioned directly on the accelerator tray and featuring significantly smaller dimensions than their previous counterparts, represent a significant step forward compared to the two-dimensional (2D) approach used in the past, which was based on computed radiography CR images with significantly lower quality. Through an in-depth analysis of homogeneity, it emerges that the new shields, thanks to their compactness and reduced size, have a higher level of homogeneity than previous versions. In particular, the unevenness, previously recorded over 10%, has now been reduced to below 5%. This results in an increased ability to absorb evenly the dose to the organs at risk, especially the lungs. This progress represents a significant contribution to the overall improvement of efficacy and safety in radiation treatments, promoting substantial advancement in the field of health physics and radiotherapy.