A dosimetric quality audit of photon beams by the Belgian Hospital Physicist Association

Hoornaert, Marie-Thérèse; Dam, J. Van; Vynckier, Stefaan; Bouiller, A.

doi:10.1016/0167-8140(93)90183-9

Cited by 9 publications

(4 citation statements)

References 7 publications

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“…As the first level in the dosimetry chain, primary standard laboratories regularly carry out intercomparisons of their provision of standard dosimetric quantities and agreement has consistently been within a few tenths of a per cent (Niatel et al 1975, Boutillon et al 1994. Secondly there have been a number of intercomparisons carried out to assess the consistency of treatment beam calibration between radiotherapy centres, making measurements under fixed conditions which either duplicate or approximate reference calibration conditions (Johansson et al 1982, 1986, Wittkamper et al 1987, Thwaites et al 1992, Hoornaert et al 1993, Wittkamper and Mijnheer 1993, Hanson et al 1994. The third group essentially assess uncertainties at other levels of the clinical dosimetry chain, and range from additional measurements in non-reference conditions to more complex intercomparisons in anatomical phantoms (Worsnop 1968, Johansson 1987, Johansson et al 1986, Wittkamper et al 1987, Thwaites et al 1992.…”

Section: Introductionmentioning

confidence: 99%

A dosimetric intercomparison of electron beams in UK radiotherapy centres

Nisbet

Thwaites²

1997

Phys. Med. Biol.

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A dosimetry intercomparison has been carried out for all 52 radiotherapy centres in the UK which possess electron treatment facilities. The intercomparison was carried out on one treatment unit in each centre and for three energies across the range of available energies. The position of the depth of maximum dose for a standard field size was independently determined and a subsequent beam calibration made. The factor to convert the reading on a calibrated ionization chamber to absorbed dose in an electron beam is energy dependent, and hence to carry out an independent calibration measurement also requires the beam energy to be determined. In addition a quantitative measure of the difference in the calibration chains between the intercomparison equipment and the host department's field instrument was carried out. In order to provide a follow-up to the initial IPSM national photon intercomparison, a photon beam calibration was measured in one photon beam in each centre. For 156 electron beam measurements, a mean ratio of intercomparison measured dose to locally measured dose of 0.994 was obtained with a standard deviation of 1.8%. For the 52 photon beam measurements, a mean ratio of intercomparison measured dose to locally measured dose of 1.003 was obtained with a standard deviation of 1.0%.

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Section: Introductionmentioning

confidence: 99%

A dosimetric intercomparison of electron beams in UK radiotherapy centres

Nisbet

Thwaites²

1997

Phys. Med. Biol.

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“…The recommendations of the NCS are applied in every radiotherapy institute in the Netherlands and Belgium since 1986. Their implementation was audited on a regular basis [6,7,11] in most of the radiotherapy centres of both countries.…”

Section: Generalmentioning

confidence: 99%

“…Note, that differences in the density of water equivalent plastics and polystyrene between manufacturers may exist [25]. 6. If an ionisation chamber is not designed for direct use in a water phantom, it must be used with a close-fitting waterproof sleeve, made of low-Z materials (e.g.…”

Section: Equipmentmentioning

confidence: 99%

NCS Report 18: Code of practice for the absorbed dose determination in high energy photon and electron beams

Aalbers¹,

Hoornaert²,

Minken³

et al. 2008

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“…External audit on radiotherapy program is settled in many countries to increase radiotherapy quality. It can be performed by visiting [1][2][3][4] participant centers or by mailing [5][6][7][8][9][10][11]. Various international organizations, such as the International Atomic Energy Agency (IAEA), Radiological Physics Center, and ESTRO-QUALity assurance network (EQUAL), operate mailed dosimetry services [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Design of Multipurpose Phantom for External Audit on Radiotherapy

Lim

2021

Progress in Medical Physics

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This study aimed to design a multipurpose dose verification phantom for external audits to secure safe and optimal radiation therapy. Methods:In this study, we used International Atomic Energy Agency (IAEA) LiF powder thermoluminescence dosimeter (TLD), which is generally used in the therapeutic radiation dose assurance project. The newly designed multipurpose phantom (MPP) consists of a container filled with water, a TLD holder, and two water-pressing covers. The size of the phantom was designed to be sufficient (30×30×30 cm 3 ). The water container was filled with water and pressed with the cover for normal incidence to be fixed. The surface of the MPP was devised to maintain the same distance from the source at all times, even in the case of oblique incidence regardless of the water level. The MPP was irradiated with 6, 10, and 15 MV photon beams from Varian Linear Accelerator and measured by a 1.25 cm 3 ionization chamber to get the correction factors. Monte Carlo (MC) simulation was also used to compare the measurements. Results:The result obtained by MC had a relatively high uncertainty of 1% at the dosimetry point, but it showed a correction factor value of 1.3% at the 5 cm point. The energy dependence was large at 6 MV and small at 15 MV. Various dosimetric parameters for external audits can be performed within an hour. Conclusions:The results allow an objective comparison of the quality assurance (QA) of individual hospitals. Therefore, this can be employed for external audits or QA systems in radiation therapy institutions.

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A dosimetric quality audit of photon beams by the Belgian Hospital Physicist Association

Cited by 9 publications

References 7 publications

A dosimetric intercomparison of electron beams in UK radiotherapy centres

A dosimetric intercomparison of electron beams in UK radiotherapy centres

NCS Report 18: Code of practice for the absorbed dose determination in high energy photon and electron beams

Design of Multipurpose Phantom for External Audit on Radiotherapy

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