Testing of Code of Practice on Small Field Dosimetry

Closed for proposals

Project Type

Coordinated Research Project

Project Code

E24021

CRP

2061

Approved Date

23 March 2015

Status

Closed

Start Date

3 September 2015

Expected End Date

2 September 2019

Completed Date

4 February 2022

Participating Countries

Cuba
Saudi Arabia

Description

Recent trends in radiotherapy techniques have increased substantially the use of small radiation fields. A key step in the radiotherapy process is the requirement for consistent reference dosimetry traceable to metrological primary standards and to enable common procedures within a country to be followed for reference dosimetry.  For conventional radiotherapy this has been achieved by Codes of Practice such as IAEA TRS 398 (IAEA, Vienna, 2000). However these Codes of Practice are all based on the use of a reference 10 cm x 10 cm field that may not be achievable using some modern specialized machines. So the developments in small field techniques have increased the uncertainty of clinical dosimetry and its link to reference dosimetry protocols. A joint working group between the IAEA and AAPM (American Association of Medical Physics) was established to prepare an International Code of Practice for small static photon fields. The aim is to harmonize the dosimetry of small fields in a similar way that IAEA TRS 398 has achieved for conventional radiotherapy. A CRP will be needed to test the procedures recommended in the new Code of Practice for different types of radiation beams and dosimeters used in special radiotherapy techniques such as various forms of Stereotactic Radiotherapy (SRT), Stereotactic Body Radiotherapy (SBRT) Stereotactic Radiosurgery (SRS) and Intensity Modulated Radiation Therapy (IMRT). Under the framework of the CRP, participants are expected to (i) contribute to the coordinated research activities, designed to test the small field Code of Practice and (ii) conduct measurements using their own radiotherapy beams and detectors, (iii) analyse and report the results of their measurements. The review of all results and discussions during RCMs will help identify implementation challenges and propose possible changes to the Code to ensure its smooth implementation in the clinic. The results of the CRP will be published in a Human Health Report to support implementation of the new Code of Practice in Member States. 

Objectives

To test the IAEA/AAPM small field code of practice, IAEA TRS 483.

Specific objectives

Test IAEA TRS483 for standard conditions.Test IAEA TRS483 for non-standard conditions.Participate in the small field audit organised by the dosimetry laboratory at Seibersdorf.Analyse the results and publish a Human Health Series Report on the findings of the CRP.

Impact

The CRP has benefited the radiotherapy community and patients in encouraging worldwide consistency for the method of measuring of absorbed dose to water for small fields. The participants of the CRP benefited by collaborating with expert agreement holders, that is demonstarted in the number of publications in peer-review journals and presentations at international conferences.

Relevance

The overall objective of this CRP was to test the new Code of Practice for small field dosimetry and assist medical physicists in its implementation in clinics in Member States. The ultimate benefit was to harmonize the dose delivered to patients receiving radiotherapy with any technology that is capable of producing small static photon fields.

CRP Publications

Year

2021

Publication URL

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8240910/

Description

Repeatability of small field output factor measurements with various detectors

Country/Organization

South Africa

Year

2022

Publication URL

https://aapm.onlinelibrary.wiley.com/doi/full/10.1002/mp.13092

Description

A dosimetric evaluation of the IAEA-AAPM TRS-483 code of practice for dosimetry of small static fields used in conventional Linac beams and comparison with IAEA TRS-398, AAPM TG51 and TG51 addendum

Country/Organization

USA

Year

2020

Publication URL

https://pubmed.ncbi.nlm.nih.gov/33953502/

Description

Effect of three-dimensional detector orientation on small field output factors

Country/Organization

South Africa

Year

2024

Publication URL

https://pubmed.ncbi.nlm.nih.gov/38700987/

Description

The IAEA remote audit of small field dosimetry for testing the implementation of the TRS-483 code of practice

Country/Organization

UN/IAEA

Year

2022

Publication URL

https://aapm.onlinelibrary.wiley.com/doi/full/10.1002/mp.15797

Description

A multi-institutional evaluation of small field output factor determination following the recommendations of IAEA/AAAPM TRS-483

Country/Organization

Austria

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