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[en] Two kinds of L-glutamine (Reanal-Hungary, Fluka-Switzerland) were applied in the spectrophotometric of gamma dosimetry. Fluka L-glutamine was applied as dosimeter of 10 MeV electron beam radiation. Two formulas were obtained for both glutamine for gamma radiation doses ranging from 0.76 kGy to 9.84 kGy. Another formula can be used in electron beam dosimetry for Fluka glutamine in doses ranging from 1.13 to 12.84 kGy. It has been shown it is necessary to calibrate a new kind of L-glutamine dosimeters each time. (author). 3 refs, 3 figs, 3 tabs
[en] Our (Royal North Shore Hospital) most recent linear accelerator acquisition is a Varian Clinac 2100C/D which has a high dose rate (approximately 25Gy per minute at 1 metre) total body electron option. We investigated the physical characteristics of the electron beam to develop a suitable method of treatment for total body electron therapy. The useful electron beam width is defined as 80cm above and below the reference height. Measurements of the electron dose received from the two angled electron beams showed a critical dependence on the gantry angles. The treatment protocol uses ten different patient angles, fractionated into directly opposing fields and treated seuqentially each day. A full cycle of treatment is completed in five days. (author)
[en] A parallel plate ionization chamber for electron dosimetry was developed and tested in relation to the metrological characteristics: short and medium-term stabilities, leakage current and response to electron beams with 13 MeV. The obtained results show that they are within the international limits recommended for a secondary standard chamber. (author)
[en] For radiation processing of matter or sterilization of medical product, it is extremely important that proper dosimetry be performed using calibrated dosimeters and internationally accepted procedures. A good and reliable electron beam dosimetry system, together with the measuring procedure, has been established with the commissioning of the electron beam irradiator, ALURTRON at MINT. An experience of good process dosimetry as part of the overall process at the ALURTRON irradiator is described
[en] Irradiation with low-energy electrons (100-300 keV) results in dose gradients across the thickness of the dosimeters that are typically used for dose measurement at these energies. This leads to different doses being measured with different thickness dosimeters irradiated at the same electron beam, resulting in difficulties in providing traceable dose measurements using reference dosimeters. In order to overcome these problems a new concept is introduced of correcting all measured doses to the average dose in the first micrometer-Dμ. We have applied this concept to dose measurements with dosimeters of different thickness at two electron accelerators operating over a range of energies. The uncertainties of the dose measurements were evaluated, and it was shown that the dose in terms of Dμ was the same at each energy for all dosimeters within the measurement uncertainty. Using the concept of Dμ it is therefore possible to calibrate and measure doses from low-energy electron irradiations with measurement traceability to national standards.
[en] A good and reliable dosimetry system together with their measuring procedure had been established for applications at an electron beam facilities at MINT. Work had been focussed on the verification of the performance of the total absorption calorimeter, which is accepted as a reference measuring system for the standardization programme of the medium energy electron beam facility (up to 3 MeV). The key element of the programme is the establishment of a relationship between the standardised beam to the routine technique which is employed to verify the beam parameter. Through this programme, the irradiation beams can be checked frequently and adoption of such programme is expected to be a core element to ensure for be proper and effective use of radiation measurements for irradiation processes using medium energy electron beams
[en] This invention comprises a procedure for the dosimetry of ionizing radiation fields by means of analytic materials on the basis of polyethyleneterephthalate (PETP) foils which can be used also for the time domain < 24 h after irradiation. It was found that a immediate constancy of measured values (alterations of transmission) can be obtained by tempering the irradiated foils (temperatures between 80 0C and 125 0C, time up to 30 min)
[en] This article presents an overview of pre-treatment verification of volumetric modulated arc therapy (VMAT) with electronic portal imaging devices (EPIDs). Challenges to VMAT verification with EPIDs are discussed including EPID sag/flex during rotation, acquisition using cine-mode imaging, image artefacts during VMAT and determining the gantry angle for each image. The major methods that have been proposed to verify VMAT with EPIDs are introduced including those using or adapting commercial software systems and non-commercial implementations. Both two-dimensional and three-dimensional methods are reviewed.