Search results for "Epr dosimetry"

Could alanine/EPR dosimetry be useful for ultra-high dose rate beams used for FLASH radiotherapy?

In the last years a large interest has aroused towards radiation therapy treatments with dose rates much larger with respect to the conventional ones since experiments support the evidence of a considerable normal tissue sparing effect. Indeed, in-vivo experiments showed an increasing of the therapeutic window for dose rates over 50 Gy/s [2]. If confirmed, the ‘FLASH effect’ has the potential to re-shape the future of radiation treatments, with a significant impact on many oncology patients. Significant dosimetric challenges should be dealt with for Ultra-high dose rate (UHDR) beams for FLASH radiotherapy [4]. In particular, ionization chambers are affected by ion recombination effects, alt…

Dosimetric characterization of an ultra-high dose rate beam for FLASH radiotherapy through alanine EPR dosimetry

2022

Experimental evidence is growing, supporting the evidence of a considerable normal tissue sparing effect when treatments are delivered with dose rates much larger with respect to the conventional ones [1]. In particular, an increasing of the therapeutic window has been demonstrated for dose rates over 50 Gy/s, over a large variety of in-vivo experiments [2]. If confirmed, the ‘FLASH effect’ has the potential to re-shape the future of radiation treatments, with a significant impact on many oncology patients [3]. Ultra-high dose rate (UHDR) beams for FLASH radiotherapy present significant dosimetric challenges [4]. Ionization chambers are affected by ion recombination effects, although novel …

The 4th international comparison on EPR dosimetry with tooth enamel

2011

This paper presents the results of the 4th International Comparison of in vitro electron paramagnetic resonance dosimetry with tooth enamel, where the performance parameters of tooth enamel dosimetry methods were compared among sixteen laboratories from all over the world. The participating laboratories were asked to determine a calibration curve with a set of tooth enamel powder samples provided by the organizers. Nine molar teeth extracted following medical indication from German donors and collected between 1997 and 2007 were prepared and irradiated at the Helmholtz Zentrum Munchen. Five out of six samples were irradiated at 0.1, 0.2, 0.5, 1.0 and 1.5 Gy air kerma; and one unirradiated s…

Planning a new international comparison on EPR dosimetry with tooth enamel: a EURADOS WG10 proposal

2018

ntroduction L-a-alanine has aroused considerable interest for use in radiation ESR dosimetry. In this work, we examined the energy response of alanine ESR films in the low energy X-photon energy range between 1 keV and 40 keV. Dose measurements through a reference ionization chamber and a semiconductor detection system were also performed to complement ESR measurements. Methods Commercial alanine ESR films were used. All ESR signal measurements were also done using an XBand (9.7 GHz) Bruker spectrometer. The dosimeters were irradiated at the "Livio Scarsi" Laboratory (LAX) of the University of Palermo, where X-ray beams in the 1–40 keV energy range are produced using a Seifert SN60 tube. Re…

Phenol compounds for EPR dosimetry in radiation therapy

2019

Monte Carlo simulation of the energy released by neutrons on organic compounds for EPR dosimetry

2022

In this work we report the analyses of the energy released per unit mass in organic compounds used for EPR dosimetry exposed to neutron beams in order to predict the increase in dose achievable by addition of gadolinium (Gd) inside the pellets. In particular, Monte Carlo (MC) simulations were carried out for alanine, ammonium tartrate and phenolic compounds irradiated with neutron beams with different energy spectra at various depths inside a water phantom. The addition of gadolinium increases sensitivity of these dosimeters to neutrons thanks to the high gadolinium cross section for neutron capture and to the large number of secondary particles (mainly Auger and internal conversion electro…

EPR DOSIMETRY IN A MIXED NEUTRON AND GAMMA RADIATION FIELD

2004

Suitability of Electron Paramagnetic Resonance (EPR) spectroscopy for criticality dosimetry was evaluated for tooth enamel, mannose and alanine pellets during the 'international intercomparison of criticality dosimetry techniques' at the SILENE reactor held in Valduc in June 2002, France. These three materials were irradiated in neutron and gamma-ray fields of various relative intensities and spectral distributions in order to evaluate their neutron sensitivity. The neutron response was found to be around 10% for tooth enamel, 45% for mannose and between 40 and 90% for alanine pellets according their type. According to the IAEA recommendations on the early estimate of criticality accident a…

EPR dosimetry intercomparison using smart phone touch screen glass

2014

International audience; This paper presents the results of an interlaboratory comparison of retrospective dosimetry using the electron paramagnetic resonance method. The test material used in this exercise was glass coming from the touch screens of smart phones that might be used as fortuitous dosimeters in a large-scale radiological incident. There were 13 participants to whom samples were dispatched, and 11 laboratories reported results. The participants received five calibration samples (0, 0.8, 2, 4, and 10 Gy) and four blindly irradiated samples (0, 0.9, 1.3, and 3.3 Gy). Participants were divided into two groups: for group A (formed by three participants), samples came from a homogene…