Verificación del comportamiento dosimétrico del sistema de planificación de tratamientos de radioterapia a través de las curvas de calibración de densidades electrónicas relativas (DER) en el Hospital de la sociedad de lucha contra el cáncer (SOLCA) núcleo Loja.

Abstract

This work aims to verify the dosimetric accuracies of Eclipse (Version 13) Treatment Planning System (TPS) using calibration curves of relative electron densities (RED) at SOLCA (Hospital de la Sociedad de Lucha Contra el Cáncer) in Loja during the period of October 2017 – February 2018. A CIRS 062M anthropomorphic phantom and a Toshiba Activion 16 CT Scan were used to obtain Hounsfield Units, and the specific electron density values were taken in the manual of that phantom to obtain the new RED calibration curve. For the dosimetric quality controls and the clinical planning of chest, pelvis, and skull cases, an Eclipse version 13 planning system, CLINAC CX, and a PTW model Farmer-type ionization chamber (sensitive volume of 0.6 cm3) connected to a PTW UNIDOS E electrometer were used. The results showed that measures taken in each one of the anthropomorphic phantom inserts did not exceed ±20 HU using the CT scan and TPS (Eclipse Version 13). The RED calibration curves showedsimilar behaviors in all types of studied inserts, but in bone one. The recommended quality control tests did not exceed the maximum limit of tolerance of ±4% established by International Atomic Energy Agency (IAEA), and the chest, pelvis and skull clinical planning, their deviations in the calculation of the absorbed-dose by TPS and the calculated dose did not exceed the tolerance of ±5% established by ICRU (International Commission on Radiation Units and Measurements).