Search results for "ESR"
showing 10 items of 190 documents
New materials for ESR dosimetry in clinical photon and electron beams: Phenol Compounds.
2016
In the last decades several research laboratories have shown an increasing interest aimed at extending the applicability of ESR-dosimetry to radiotherapy with different types of radiation beams. ESR is a spectroscopic method for investigating the structure and dynamics of such paramagnetic species. The concentration of radiation-induced free radicals is proportional to the energy released inside in the medium. Our research group has started an investigation of the ESR response of some phenols compounds for possible ESR dosimetric applications suitable features, such as high efficiency of radiation-matter energy transfer and radical stability at room temperature. In particular, the phenoloct…
Electron Spin Resonance (ESR) characterization of phenol compounds as new materials for dosimetry in radiotherapy
2016
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 [1]. Free radicals are known to be produced when a compound is irradiated with ionizing radiations. The concentration of radiation-induced free radicals is proportional to the absorbed dos e and this allows for dosimetric measurements through ESR technique which able to quantitatively determine the radical concentration [2]. Our research group has started an investigation of the ESR response of some phenols compounds for possible ESR dosimetric ap plications suitable feature…
Phenol compounds as new materials for Electron Paramagnetic Resonance dosimetry in clinical photon and electron beams,
2016
In the last decades several research laboratories have shown an increasing interest aimed at extending the applicability of Electron Paramagnetic Resonance (EPR) dosimetry to radiotherapy with different types of radiation beams. EPR is a spectroscopic method for investigating the structure and dynamics of such paramagnetic species. Free radicals are known to be produced when a compound is irradiated with ionizing radiations. The concentration of radiation-induced free radicals is proportional to the energy released inside in the medium and this allows for dosimetric measurements through EPR technique. The use of alanine as a dosimetric material gave the possibility to apply EPR spectroscopy…
Nuovi composti fenolici per la dosimetria a risonanza di spin elettronico (ESR) in campo misto neutroni-gamma
2014
Dosimetria tramite Risonanza Elettronica di Spin (ESR) in RadioTerapia IntraOperatoria (IORT): misure di Output Factors e simulazioni Monte Carlo-GEA…
2016
La RadioTerapia IntraOperatoria (IORT) è una modalità di trattamento in cui una singola dose di radiazioni è impartita direttamente al letto tumorale o al tumore durante l'intervento chirurgico, evitando di colpire i tessuti sani circostanti. La fabbricazione di acceleratori lineari mobili per elettroni dedicati alla IORT ha permesso una grande diffusione di questa tecnica radioterapica. Lo scopo di questo lavoro è il confronto tra la risposta di dosimetri di alanina letti tramite Risonanza Elettronica di Spin (ESR) e di camere a ionizzazione Markus per le misurazioni degli Output Factors (OFs) di fasci di elettroni prodotti da un acceleratore lineare utilizzato per la IORT. Gli OFs dei fas…
Characterization of the terminal column of TRIGA Mark II reactor of Mainz through of alanine pellets.
2017
We have studied the ESR response of alanine pellets with and without gadolinium exposed to the thermal column of the TRIGA Mark II research reactor at the University of Mainz (Germany). The choice of Gd as additive nucleus is due to its very high capture cross section to thermal neutrons and to the possibility for secondary particles produced after interaction with thermal neutrons of releasing their energy in the neighborhood of the reaction site. In particular, it was found that low concentration (5% by weight) of Gd brings about a neutron sensitivity enhancement of more than 10 times without heavily reducing tissue equivalence. Monte Carlo (MC) simulations of both response of alanine and…
Dose verification with EPR/alanine dosimeters in Helical Tomotherapy Stereotactic Radiosurgery (HT SRS) treatments
2016
Intracranial stereotactic radiosurgery (SRS) is a technique to deliver an ablative radiation dose with an extremely sharp dose gradient to small brain tumors. This tecnique allows to deliver high doses of radiation to the tumor sparing the surrounding healthy tissue. In this study the accuracy of the dose delivered in a SRS session by a non conventional radiotherapy machine, the TomoTherapy Hi-Art System, was investigated using an "end-to-end" test. This is perfome d by means of alanine Electron Paramagnetic Resonance (EPR) pe llets. The response of these dosimeters is compared to that of gafchromic films which are particularly suitable for two-dimensional dose verification providing accura…