INVESTIGADORES
VALENTE Mauro Andres
congresos y reuniones científicas
Título:
Photon beam depth dose profiles: comparisons between homogeneous and inhomogeneous irradiated phantoms
Autor/es:
I. HURTADO, J. VELASQUEZ & M. VALENTE
Lugar:
Pucon
Reunión:
Congreso; Reunion Anual de Sociedad Chilena de Fisica SOCHIFI; 2010
Institución organizadora:
Sociedad Chilena de Fisica SOCHIFI
Resumen:
Photon and electron beams are the radiation types most commonly used fortherapy purposes. Actually, international radiotherapy Protocols establish thattreatment beam dosimetric characterizations need to be carefully and suitablyperformed in order to assess the required quality assurance levels.Almost all dosimetric quantities and associated clinical beam properties arede ned, according to internation Protocols, for speci c reproducible situations.Therefore, liquid water is usually employed as reference irradiated medium.However, real patient cases do not match exactly the same radiation absorptionand scattering properties like liquid water. Actually, patient have non negligibleinhomogeneities along beam path, which need to be taken into acount in orderto achieve suitable dosimetric charaterization.This work presents a review of the analytical models and International Pro-tocol (TRS-398) recommendations dedicated to the correction of absorbed dosedistributions due to the presence of inhomogeneities in the irradiated phan-tom/patient. A dedicated Monte Carlo program, based on the PENELOPEv.2008 main code, has been developed with the aim of peforming suitable com-plete stochastic simulations of radiation transport within inhomogeneous mediaconstituted od di erent materials typically found in clinical situations, like softtissue, compact bone and lung tissue. The developed Monte Carlo program wasable to perform absorbed dose computation for di erent radiation qualities inhomogeneous situations as well as to determine depth-dose and 3D dose distri-butions within inhomogeneous media. These results have been used for com-parison with di erent analytical models proposed to inhomogeneity corrections.Therefore, it was possible to determine which one of the considered correctionmodel may assess better performance for inhomogeneity corrections.
