Search results for "DOSIMETRY"

Characterization of Fricke gel dosimeters exposed to clinical photons beams and of MRI dosimetrical applications

2014

RENEB Inter-Laboratory Comparison 2021: Inter-Assay Comparison of Eight Dosimetry Assays

2023

Tools for radiation exposure reconstruction are required to support the medical management of radiation victims in radiological or nuclear incidents. Different biological and physical dosimetry assays can be used for various exposure scenarios to estimate the dose of ionizing radiation a person has absorbed. Regular validation of the techniques through inter-laboratory comparisons (ILC) is essential to guarantee high quality results. In the current RENEB inter-laboratory comparison, the performance quality of established cytogenetic assays [dicentric chromosome assay (DCA), cytokinesis-block micronucleus assay (CBMN), stable chromosomal translocation assay (FISH) and premature chromosome co…

ESR dosimetry with alanine added with Gadolinium in TRIGA reactor of Mainz

2014

Testing and linearity calibration of films of phenol compounds exposed to thermal neutron field for EPR dosimetry

2015

This paper reports the preliminary results obtained by Electron Paramagnetic Resonance (EPR) measurements on films of IRGANOX® 1076 phenols with and without low content (5% by weight) of gadolinium oxide (Gd2O3) exposed in the thermal column of the Triga Mark II reactor of LENA (Laboratorio Energia Nucleare Applicata) of Pavia (Italy). Thanks to their size, the phenolic films here presented are good devices for the dosimetry of beams with high dose gradient and which require accurate knowledge of the precise dose delivered. The dependence of EPR signal as function of neutron dose was investigated in the fluence range between 10(11) cm(-2) and 10(14) cm(-2). Linearity of EPR response was fou…

Dosimetry of Mainz reactors by means of ESR dosimetry with alanine added with gadolinium

2014

Gel dosimeters for medical physics applications

2015

Gel dosimeters for three-dimensional mapping of radiotherapy doses were introduced at Yale University in the mid-1980’s. Soon after, R&D in this field also started in Italy. Early work was done at the Istituto Superiore di Sanità, and at the Universities of Pisa and Milan. Several institutes now collaborate on this topic with support from the Italian Ministry for University and Research (MIUR) through Grant PRIN SNALEM2010 “Development and application of new materials for ionizing radiation dosimetry”. This presentation describes this research, which aims at developing new formulations of hydrogel matrices with improved characteristics of stability, sensitivity and spatial resolution co…

Phenol compounds as new materials for electron spin resonance dosimetry in radiotherapy

2016

Introduction: Among the various dosimetric techniques used for characterizing the radiation beams used in radiation therapy, the electron spin resonance (ESR) arouses increasing interest for applications in various therapy procedures. Free radicals are known to be produced when a compound is irradiated with ionizing radiations. The concentration of radiationinduced free radicals is proportional to the absorbed dose and this allows for dosimetric measurements through ESR technique which enables to quantitatively determine the radical concentration. In this work we report the ESR investigation of phenol pellets and thin films exposed to various types of radiation beams (clinical photon and el…

PVA gel dosimeters for radiotherapy applications,

2015

Gel dosimeters for three-dimensional mapping of radiotherapy doses were introduced at Yale University in the mid-1980’s. Soon after, research and development in this field also started in Italy. Early work was done at the Istituto Superiore di Sanità, and at the Universities of Pisa and Milan. Several institutes now collaborate on this topic with the goal of developing new formulations of hydrogel matrices with improved characteristics of stability, sensitivity and spatial resolution compared to those of earlier Fricke-gel and polymer-gel systems. Contrary to earlier gels based on natural gelling agents, such as porcine skin gelatin and/or agarose, which suffer from limited batch -to-batch …

Investigation of relaxation times of irradiated Fricke gels by means of nuclear magnetic resonance relaxometry

2016

Fricke gel dosimeters are ideal candidates to provide 3D maps of dose distributions and are particularly useful in the plann ing and verification phase of radiotherapy treatments. One of the most effective experimental techniques to reconstruct dose maps is magnetic resonance imaging (MRI). This measures th e nuclear relaxation times variations induced by irradiation. In this work, we analyzed Fricke gels with and without Xylenol Orange by means of a single side-NMR relaxometer (which is abl e to provide information on both relaxation relaxation times T1 and T2 and is mainly used in the field of diagnostics for Cultural Heritage [1-2] to perform porosimetry meaurements). Our goal was to per…

EPR ANALYSIS OF ALANINE WITH GADOLINIUM FOR DOSIMETRY AT TRIGA MARK II REACTOR OF MAINZ

2015

Negli ultimi anni il crescente interesse verso la radioterapia a cattura neutronica (internazionalmente nota come Neutron Capture Therapy - NCT) per il trattamento di neoplasie ha stimolato diverse attività di ricerca finalizzate alla caratterizzazione del fascio utilizzato e all'ottimizzazione delle procedure radioterapiche. La corretta riuscita del trattamento NCT e il monitoraggio della dose impartita non possono prescindere dalla valutazione delle varie componenti del fascio impiegato (neutronica e fotonica). Infatti, durante le procedure di moderazione dei neutroni, si verifica la produzione di fotoni e la stima dei rischi a cui sono soggetti i tessuti sani sottoposti al campo misto ne…