Implementation of electron density curves relative to the treatment planning system in teletherapy using stoichiometric calibration

Cadillo R.R.P.; Calcina C.S.G.; Chávez C.P.; Velásquez J.A.M.; Herrera J.B.V. · Gaceta Medica Boliviana (2024) · DOI: 10.47993/gmb.v47i1.699

Resumen

Objectives: the objective of this work was to integrate relative electron density curves to the CAT3D treatment planning system using the alternative method of stoichiometric calibration. Methods: aluminum was used as calibration material and a thoracic mannequin with inserts and 3 cases were considered in the treatment planning: direct field 10x10cm2, direct field 20x20cm2 and lateral field 10x10cm2 with wedge, where the planning system based on the Pencil Beam algorithm was tested. Results: it was found that incorrect use of these curves significantly affects the absorbed dose by up to 6% in regions of sudden changes in density, exceeding the recommended tolerance of ±5% in the delivery of adsorbed dose in regions of electronic equilibrium. Conclusions: it was concluded that the implementation and correct use of these curves improves the approximation in heterogeneous media, reducing the deviation of their results.

Instituciones: Universidad Ricardo Palma; Universidad Nacional de Ingeniería; Universidad Nacional Federico Villarreal; Universidad Nacional del Callao