APPLICATION OF MATHEMATICAL TRANSFORMATIONS FOR THE MEDICAL ELECTRON BEAM PROFILE DETERMINETION

Currently, radiation therapy is often used for treating cancer. In this method, ionizing radiation affects cancer cells, slowing down their reproduction; however, healthy tissues are also exposed to the irradiation. Therefore, an important stage of treatment planning is to ensure control over the energy distribution of the beam in the transverse plane. In order to obtain the transverse profile of the beam various detectors are created. However, most of them do not meet all the requirements for modern medical detectors, which include the high energy and spatial resolution, as well as the minimalizing of data processing and result obtaining. The multi-angle scanning method could be a solution of this problem. This method is based on repeated linear displacement of the detector in a plane perpendicular to the beam propagation axis at different angles. The data processing involves the reconstruction of beams’ intensities image in the form of pixels of different brightness in grayscale from the data obtained in the experiment. The purpose of this study is to assess the applicability of the main types of mathematical transformations for the implementation of the multi-angle scanning method. This article presents the results of a comparison of the iterative method and the filtered back-projection method with the comprehensive and limited data given. It was found that the filtered back-projection method is less accurate in the presence of comprehensive dataset in contrast to the iterative method, but it still provides better image resolution when there is a limited data.

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