Monte Carlo simulation of an optimized EDXRF system for detecting simultaneously gold and silver nanoparticles used like multi-parametric imaging of tumor characteristics

R. SAAVEDRA; M. SANTIBANEZ; M. VALENTE; R. FIGUEROA

Carlos Paz

Congreso; 7mo Congreso ALFIM & 13avo Congreso SAFIM; 2016

ALFIM & SAFIM

p { margin-bottom: 0.1in; direction: ltr; line-height: 120%; text-align: left; widows: 2; orphans: 2; }a:link { color: rgb(0, 0, 255); }During thelast years has been proposed the utilization of Gold and Silvernanoparticles like bio-markers when are bound to molecules likeantibodies, which are linked to specifics cell receptors. Theadvances achieved in this field have proposed the future use of thenanoparticles for detection of small clusters of infiltrating cancer,provide information of tumor characteristics to map the diseasestate, distribution and radiosensibility of the tumor cells andgenerating images to producing personalized cancer therapy regimes.Therefore, the use of gold and silver nanoparticles with specificmarkers would provide information of these bio-parameters, and thusindividualize treatments depending on the conditions of the tumormicroenvironment. One of the common challenges that presented theusing these new agents is to develop methodologies for in vivodetection, simultaneously and with greater sensitivity when areprovided to the organism. In this work is simulated an optimizedEDXRF system, which allow simultaneously quantify in vivo gold andsilver nanoparticles into tumor phantoms, generating amulti-parametric imaging of specific tumor characteristics. Thesystem was simulated using XMI-MSIM software designed to predict theXRF spectral response using Monte Carlo simulations. The studiedsetup is comprised of an mini X-ray tube and a set of Se, Sr, Y, Zr,filters, for exiting the gold L3-edge, and Cd, In and Sn, filters,for exiting the silver K-edge. This simulated setup was configuredwith variable thickness, for emit simultaneously two spectrallynarrow beam centered on a specific excitation energy. The meritfigures used for adjusted the composition and filters thickness wereminimizing the detection limit and radiation exposure. Fordetermining the experimental detection limit, several concentrationsranging from 0.05 to 10 mgAu/ml were measured into the tumor phantomsconsidering a statistical fluctuation with a 95% of confidence level.The ranging of concentration studied corresponds to the possible goldand silver concentrations expected to be found in future in vivoapplication in human.