Prospects of the multiangle scanning method for determining the transverse profile of a medical electron beam

Abstract

This study is aimed at assessing the applicability of the proposed method of multiangle beam scanning for determining the transverse profile of an electron beam. The application area of the proposed approach will be control of the therapeutic beams spatial and dose characteristics in order to increase the irradiation accuracy and, as a result, reduce the side effects of radiation therapy. One of the main applied problems to be solved by the proposed approach is to determine the beam characteristics during electron beam therapy. For carrying out of electron beam therapy procedures it is necessary to form electron beams with the complex shape of transverse profile. The need to precisely control beam shapes throughout all irradiation stages determines the relevance of this study. The integral transform method was used in this study to obtain distributions of medical electron beam intensity. For the study, we used electron beam transverse pro-files calculated on the basis of a radiation therapy planning system for real clinical cases. The method was applied both theoretical beam profiles with sharp edge and to ones experimentally obtained with real medical electron beams. Integral transforms were performed for a different number of scan projections. Due to this, the optimal number of projections was calculated for each considered profile. The results of the study demonstrate that the multiangle beam scanning method needs 12 scan projections which corresponds to an angular displacement of 15° to control the medical electron beam profile.