{"status":"OK","msg":"Details loaded!","presentation":{"id":23,"title":"OPTIMIZATION OF A LOW DOSIS AND HIGH SENSITIVITY BENCHTOP EDXRF SYSTEM FOR IN VIVO QUANTIFICATION OF GOLD NANOPARTICLES IN TUMOR TISSUE","abstract":"In the recent years different nanoparticles agents have been proposed for produce diagnostic images of tumor areas and simultaneously the application of highly localized treatment. The most studied are the Gold nanoparticles (GNPs) that are enhancer of local dose delivery for orthovoltage radiotherapy and a contrast agent with a better attenuation that the traditional compounds used. One of the common challenges that presented the using these new agents is to develop methodologies for detection in vivo, quickly, efficiently and with greater sensitivity when are provided to the organism. Given that the effectiveness of their applications require knowing exactly the concentration and distribution in the volumes of study. In this work is optimized a benchtop L X-ray system of low power (4 W), which allow quantify in vivo low concentrations of gold nanoparticles into tumor phantoms, with the minimum surface dose. The studied dephs for the tumor phantoms were 0-4 mm of depths in tissue equivalent, with a fixed volumen of 0.3 cm3. The composition of the doped tumor phantoms consisted of a solution of GNPs (1.9 nm AurovistTM, Nanoprobes Inc.) suspended in de-ionized water. For the optimization procces, a set of measurement were carried out for determining the optimal incident spectrum which minimized the limit of detection and the dosis. Several tube voltages (kVp) and alluminium filters of different thicknesses (0.75 mm to 3 mm) for each kVp were configured to obtain a non-symmetrical narrow spectrum with a fixed FWHM and centered between the 8-20 keV. For determining the experimental detection limit, several GNPs concentrations ranging from 0.05 to 10 mgAu\/ml were measured into the tumor phantoms at the dephs previously selected and considering a statistical fluctuantion with a 95% of confidence level. The ranging of concentration and depths selected, corresponds to the possible tumour gold concentrations for in vivo aplication. ","keywords":"Gold nanoparticles, in vivo EDXRF, Targeting-radiotherapy ","status":"active","sarx_st":"accepted","user_id":32,"created_at":"2016-04-06 20:55:37","updated_at":"2016-08-20 12:32:04","filename":"Abstract (SARX2016).pdf","mode":"oral","sarx_code":"19_O-XRF","poster_group":null,"file":"050e333fbe25666b609de2b8a08f0bfb.pdf","author":"Mauricio Santiba\u00f1ez","affiliation":"PhD in Physics \/<\/b> Universidad de La Frontera \/<\/b> Chile","user":{"id":32,"name":"Mauricio Santiba\u00f1ez","degree":"PhD in Physics","email":"mauricio.santibanez@ufrontera.cl","username":"mauricio.santibanez@ufrontera.cl","confirmed":0,"confirmation_code":"PkBmwViK7dZ9BCXFYwqyCBhq18ymXD","created_at":"2016-03-28 18:59:14","updated_at":"2016-05-23 15:43:17","sarx":1,"affiliation":"Universidad de La Frontera","address":"Avda. Francisco Salazar 01145, Temuco","zipcode":"4811230","state":"Araucania","phone":"+56452596619","fax":null,"city":"Temuco","country":"Chile","status":"active","is_admin":0,"category":"professor","school":0,"icdd":0}}}