RADIOACTIVE ISOTOPES

Author: ROJAS CALDERÓN EVA LETICIA.
Year: 2003.
University: GRANADA [www.ugr.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: OBJECTIVES To conduct dosimetric calculations by the Monte Carlo simulation code PENELOPE three applications with radiotherapy treatments with heterogeneities in the middle: cystic craniopharyngiomas, sinovectormía the knee and radiocirugía with Lekseel Gamma Knife. METHODOLOGY dosimetric calculations are made by Monte Carlo simulation to two treatments with radiocoloides, cystic craniopharyngiomas and sinovectomía in the knee joint, for cases with a single medium and with various media. Moreover compared to the case of craniopharyngiomas, with the results that are obtained in an analytical way. An estimated profiles dose for the treatment of radiocirugía with the Gamma Knife for cases half a uniform and non-homogeneous by Monte Carlo simulation. RESULTS It shows the correlation between the dosimetry made by analytical calculations and by Monte Carlo simulation, for a craneofaringioma Cystic homogeneous treated radiocoloides containing an issuer or a pure beta emitter beta-gamma. They show differences that are considered when calculating the dose one medium or several media using Monte Carlo simulation with the code PENELOPE in treatments craneofaingiomas cystic, sinovectomía the knee and radiocirugía with the Leksell Gamma Knife. Are dependence of the dose to the size of craniopharyngiomas and tissues of the knee joint in treatments radiocoloides. It quantify changes in the profiles of doses that may be obtained from treatments radiocirugía with the Gamma Knife when it includes an interface bone in a spherical mannequin. We found that these changes are so great about the interface. CONCLUSION It is important to consider the presence of several ways to perform dosimetry for treatment with radiocoloides for cystic craniopharyngiomas, the knee joint and treatments radiocirugía the head with the Gamma Knife. They carefully measured the thickness of tissues to treat with radiocoloides. The dosimetry done by Monte Carlo simulation with the code PENELOPE is a good choice of calculation in the case of problems with radiotherapy interfaces. KEYWORDS: Dosimetry, Monte Carlos, PENEOLOPE, Craniopharyngiomas Quísticos, Sinovectomía, Gamma Knife.

Author: Rojas Calderón Eva Leticia.
Year: 2003.
University: GRANADA [www.ugr.es].
Place of defense: Facultad de Ciencias.
Place of preparation: Facultad de Ciencias.

Summary: Objective. Conducting dosimetric calculations by the Monte Carlo simulation code PENELOPE three applications with radiotherapy treatments with heterogeneities in the middle: cystic craniopharyngiomas, sinovectomía the knee and radiocirugía with the Leksell Gamma Knife. Methodology. It dosimetric calculations performed by Monte Carlo simulation to two treatments with radiocoloides, cystic craniopharyngiomas and sinovectomía in the knee joint, for cases with a single medium and with various media. Moreover compared to the case of craniopharyngiomas, with the results that are obtained in an analytical way. An estimated profiles dose for the treatment of radiocirugía with the Gamma Knife for cases half a uniform and non-homogeneous by Monte Carlo simulation. Results. It shows the correlation between the dosimetry made by analytical calculations and by Monte Carlo simulation, for a craneofaringiom!

Author: SALAS GARCÍA ALEJANDRO.
Year: 2004.
University: EXTREMADURA [www.unex.es].
Place of defense: FACULTAD DE VETERINARIA.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: Study incorporables improvements to the processes of purification to remove the contents of these natural radioactivity possess. Such improvements should be easy to implement and economically by the people thereby anyway water physical chemistry and organolépticamente drinking according to the legislation.

Author: Granero Cabañero Domingo.
Year: 2005.
University: VALENCIA [www.uv.es].
Place of defense: Facultad de Física, Universitat de València.
Place of preparation: Facultad de Física, Universitat de València.

Summary: This thesis presents, as a collection of publications, a series of studies related to obtaining matrices dose rate sources and applicators used in brachytherapy using the Monte Carlo method. There has been a study of the influence of size on the mannequin used matrices dose rate. In this study are obtained sizes "optimal" maniquís to bring it closer to unlimited sources for R-125, Pd-103, Ir-192 and Cs-137. That has been obtained for the I-125 and Pd-103 a mannequin spherical radius of 15 cm can be seen as limitless and for sources of 137Cs and 192Ir one of 40 cm in radius. There have been also differences in the distributions of dose rate depending on the size of the mannequin in which these have been calculated and a relationship that allows you to compare distributions of dose rate obtained with phantoms of different sizes. It has made a detailed study of dosimetric sources CSM2 and CSM3 of Cs - 137, the sources Alpha-Omega and Steel-Clad of Ir-192, the sources Radiation Therapy Resources and 3M of Cs - 137 and the source of high Jump - 192 BEBIG. These studies improve the existing literature. There have been distributions dose rate produced by the applicator eye ROPES, for brachytherapy epiescleral. The study was conducted with the applicator loaded with radioactive seeds R-125 type 6711. It has also been studied precision in the calculations of a dosimetric planning system devoted to brachytherapy epiescleral. We compared the distribution of dose rate provided by the planner eye Plaque Simulator with that obtained by Monte Carlo for the applicator ROPES getting a good agreement on the central axis of applicator. We have studied the distribution of dose rate produced by the Leipzig applicators (Nucletron, Netherlands) used in the treatment of superficial injuries. These distributions obtained can be used as input to a system of planning. Finally characteristics were studied from the point of view of radiation protection of the isotopes, Tm-170 and Yb-169, whose use can be very interesting in brachytherapy because it combines a high specific activity with a mean energy rather low. Specifically, the calculated curves transmission lead and concrete, which are essential elements for designing the barriers of an installation to use these isotopes.