Study of the behavior of the dosimetric parameters in two linear accelerators, a reconditioned and other high technology used in the radiotherapy

Abstract

In this study, we examined the behavior of dosimetric parameters most commonly used in the calculation of doses that are responsible for monitor units used in the treatment of radiotherapy with photon beams of 6 MV of two linear accelerators from different manufacturers, in order to check whether there are differences ceded significant doses to patients undergoing radiotherapy. The parameters used in the evaluation were: percentage depth dose (PDP), tissue maximum ratio (TMR) and output factors (FR). Before the data analysis, we conclude that the largest variations to the PDP’s and TMR’s were found in more depths, and the maximum variation for both parameters around 5%. Considering the factors of income, the differences were around 1%. Although the results of dosimetric parameters evaluated exhibit differences for the two accelerators, they do not generate significant variations in doses to patients assigned to radiotherapy in the analysis of distributions of doses in a three-dimensional medical planning system used in conformal radiotherapy treatment.