Comparison of the standards for absorbed dose to water of the BNM-LNHB and the BIPM for <sup>60</sup>Co γ rays

Allisy-Roberts, P J; Burns, D T; Kessler, C; Delaunay, F.; Leroy, Éric

doi:10.1088/0026-1394/42/1a/06006

Cited by 9 publications

(7 citation statements)

References 13 publications

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“…However, the values of Palmans et al are lower by about 0.8%, which is consistent with the N D,w /N K ratios in both investigations. For the Belgium laboratory, the ratio is 1.1% higher than for the BIPM (Allisy-Roberts et al 2000), to which the chambers used by Andreo et al were traceable. In the work by Palmans et al (2002), the air kerma standard was lowered by 0.3% compared with the routine value disseminated to the Belgian hospitals, to account for an error in the K wall value.…”

Section: Comparison Betweenmentioning

confidence: 74%

Advances in the determination of absorbed dose to water in clinical high-energy photon and electron beams using ionization chambers

Huq

Andreo

2004

Phys. Med. Biol.

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During the last two decades, absorbed dose to water in clinical photon and electron beams was determined using dosimetry protocols and codes of practice based on radiation metrology standards of air kerma. It is now recommended that clinical reference dosimetry be based on standards of absorbed dose to water. Newer protocols for the dosimetry of radiotherapy beams, based on the use of an ionization chamber calibrated in terms of absorbed dose to water, N(D,w), in a standards laboratory's reference quality beam, have been published by several national or regional scientific societies and international organizations. Since the publication of these protocols multiple theoretical and experimental dosimetry comparisons between the various N(D,w) based recommendations, and between the N(D,w) and the former air kerma (NK) based protocols, have been published. This paper provides a comprehensive review of the dosimetry protocols based on these standards and of the intercomparisons of the different protocols published in the literature, discussing the reasons for the observed discrepancies between them. A summary of the various types of standards of absorbed dose to water, together with an analysis of the uncertainties along the various steps of the dosimetry chain for the two types of formalism, is also included. It is emphasized that the NK-N(D,air) and N(D,w) formalisms have very similar uncertainty when the same criteria are used for both procedures. Arguments are provided in support of the recommendation for a change in reference dosimetry based on standards of absorbed dose to water.

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Section: Comparison Betweenmentioning

confidence: 74%

Advances in the determination of absorbed dose to water in clinical high-energy photon and electron beams using ionization chambers

Huq

Andreo

2004

Phys. Med. Biol.

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“…For a 60 Co beam, the absorbed dose to graphite in a homogeneous graphite phantom (30 cm × 30 cm × 20 cm) at a depth of 5 g cm −2 was determined from the calorimetric measurements [26,27]. The absorbed dose to water was derived from the absorbed dose to graphite using transfer dosimeters (ionization chambers and Fricke dosimeters) placed successively in the graphite and water phantoms [28,29]. The absorbed dose to water for the linac beams was derived from the absorbed dose to water of the 60 Co beam using ionization chambers and Fricke dosimeters as transfer instruments placed successively in the 60 Co and the linac beams in the water phantoms, with an energy dependence taken from the literature [30].…”

Section: Introductionmentioning

confidence: 99%

New standards of absorbed dose to water under reference conditions by graphite calorimetry for⁶⁰Co and high-energy x-rays at LNE-LNHB

Delaunay¹,

Gouriou²,

Daures³

et al. 2014

Metrologia

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The LNE-LNHB has developed two primary standards to determine the absorbed dose to water under reference conditions (for 10 cm × 10 cm) in 60 Co, 6 MV, 12 MV and 20 MV photon beams: a new graphite calorimeter and a water calorimeter. This first paper presents the results obtained with the graphite calorimeter and the new associated methodology. The associated relative standard uncertainty (k = 1) of absorbed dose to water is 0.25% for 60 Co and lies between 0.32% to 0.35% for MV x-ray beams.

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“…See the relevant RMO Final Report in the KCDB for the approximation used for U i in the Matrix of equivalence. ( 14) of which the final two terms take into account the correlations between the primary standard methods.…”

Section: Linking Simri(i)-k4 or Eurometri(i)-k4 To Bipmri(i)-k4mentioning

confidence: 99%

Comparison of the standards for absorbed dose to water of the NPL, United Kingdom and the BIPM for⁶⁰Co γ rays

Kessler¹,

Allisy²,

Burns³

et al. 2012

Metrologia

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A comparison of the standards for absorbed dose to water of the National Physical Laboratory (NPL), United Kingdom and of the Bureau International des Poids et Mesures (BIPM) has been made in 60 Co gamma radiation under the auspices of the key comparison BIPM.RI(I)-K4. The comparison result, based on the calibration coefficients for two transfer standards and expressed as a ratio of the NPL and the BIPM standards for absorbed dose to water, is 0.9980 (0.0064). The degrees of equivalence for the NPL and the other participants in this comparison have been calculated and the results are given in the form of a table for the eleven national metrology institutes (NMIs) that have taken part in the ongoing comparison for absorbed dose to water. A graphical presentation is also given.

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Comparison of the standards for absorbed dose to water of the BNM-LNHB and the BIPM for ⁶⁰Co γ rays

Cited by 9 publications

References 13 publications

Advances in the determination of absorbed dose to water in clinical high-energy photon and electron beams using ionization chambers

Advances in the determination of absorbed dose to water in clinical high-energy photon and electron beams using ionization chambers

New standards of absorbed dose to water under reference conditions by graphite calorimetry for⁶⁰Co and high-energy x-rays at LNE-LNHB

Comparison of the standards for absorbed dose to water of the NPL, United Kingdom and the BIPM for⁶⁰Co γ rays

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Comparison of the standards for absorbed dose to water of the BNM-LNHB and the BIPM for 60Co γ rays

Cited by 9 publications

References 13 publications

Advances in the determination of absorbed dose to water in clinical high-energy photon and electron beams using ionization chambers

Advances in the determination of absorbed dose to water in clinical high-energy photon and electron beams using ionization chambers

New standards of absorbed dose to water under reference conditions by graphite calorimetry for60Co and high-energy x-rays at LNE-LNHB

Comparison of the standards for absorbed dose to water of the NPL, United Kingdom and the BIPM for60Co γ rays

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Resources

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Comparison of the standards for absorbed dose to water of the BNM-LNHB and the BIPM for ⁶⁰Co γ rays

New standards of absorbed dose to water under reference conditions by graphite calorimetry for⁶⁰Co and high-energy x-rays at LNE-LNHB

Comparison of the standards for absorbed dose to water of the NPL, United Kingdom and the BIPM for⁶⁰Co γ rays