Table of contents for this page
(Please click on the relevant section link below)
1. Supervision
2. Purpose
3. Use
4. Disclaimer
5. Methods and Materials
5.1 High-energy sources
5.2 Seed sources
5.3 Research material
5.4 Sources not included
6. Physics background
7. Special dosimetric considerations
8. List of sources
1. Supervision
The data presented in this website were prepared under the supervision of an expert group.
- Facundo Ballester, Dept. Of Atomic, Molecular and Nuclear Physics, University of Valencia and IFIC, Burjassot, Spain.
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Dimos Baltas, Dept. of Medical Physics & Engineering, Klinikum Offenbach, Germany.
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Rob van der Laarse, 3707 HB/83 Zeist, The Netherlands.
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José Pérez-Calatayud, Radiotherapy Dept., La Fe Hospital, Valencia, Spain.
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Alex Rijnders, Dept. Radiotherapy, Europe Hospitals "2-Alices", Brussels, Belgium.
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Jack Venselaar, Dept. Radiotherapy, Dr. B. Verbeeten Institute, Tilburg, The Netherlands.
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Panagiotis Papagiannis, Medical Physics Laboratory, Medical School, University of Athens, Greece.
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Mark Rivard, Tufts University, Boston, USA.
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2. Purpose
The purpose of presenting the material on this website is:
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To provide treatment planning users with a single set of consensus data, obtained from the available publications.
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To facilitate easy data entry to treatment planning systems.
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To assist the validation of treatment planning system calculations.
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3. Use
It is assumed that the user is aware of the information presented in this website. The user should have proper knowledge of the physics background before copying data or making changes in existing clinical procedures. The user is strongly advised to study the original publications from which the data sets were prepared. Please see Physics Background
For each source a set of numerical tables is provided in MS/Excel format. For normal operations, copying and pasting the data should be sufficient as manipulation steps.
For each source along and away dose rate tables, in consistency with the other data, are provided as a means to verify the outcome of the treatment planning system. It is the full responsibility of the user to validate the correct implementation of the source data in the treatment planning system
The basic tasks of ESTRO (European Society for Therapeutic Radiology and Oncology) are the organisation of scientific meetings of experts in the field of radiotherapy, the organisation of educational activities, and the stimulation of quality assurance programmes in the field of radiation oncology. TG-43 data presented in this website are carefully reviewed consensus data, which were taken and summarized to their present form by the expert group.
TG-43 data sets are presented for ESTRO members and others with the aim to use these data as a tool for quality control and completion or updating the customized data in the treatment planning system. The website aims to provide easy access to a single set of consensus data originating from often widely distributed, and sometimes incomplete published material.
ESTRO cannot, however, take any responsibility for the accuracy and use of these data in clinical practice, either for any error in one or more of the numerical values, nor for any other reason. The medical physicist of the institution is the responsible person for the proper implementation or validation of TG-43 data in the treatment planning system used clinically.
The website focuses on high-energy photon-emitting sources used in manual and remotely controlled afterloading brachytherapy techniques: caesium-137, iridium-192 and cobalt-60, and one caesium-131 source. Dosimetry data sets are also included for some of the iodine-125 and palladium-103 low-energy emitting sources which comply with the dosimetric prerequisites of the AAPM TG-43 subcommittee.
These prerequisites were published by the American Association of Physicists in Medicine (AAPM, Williamson et al. Med.Phys. 25, 2269-2270, 1998; and Rivard et al. Med. Phys.31:633-674,2004) as a guidance to manufacturers involved in the development of new brachytherapy seed sources. The prerequisites include:
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The vendor provides RAKR calibrations that are traceable directly or indirectly, to NIST99 standard.
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The vendor has confirmed that the calibration from NIST has been transferred to the ADCLs (Accredited Dosimetry Calibration Laboratory).
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The vendor has implemented a program of periodically intercomparing its RAKR calibrations with NIST primary standard and the secondary standards maintained by the ADCLs.
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A set of dosimetric parameters supports both the calculation of the 2-D dose-rate distribution and the 1-D isotropic point source approximation. The set must have been determined by the independent investigators, and have been accepted for publication by a peer-reviewed journal.
A full set of TG-43 dosimetric parameters is available in the present website for the selected sources, including references to the abstracts of the original publications. A drawing of the source contribution is provided for each source, either taken from the publication or obtained from the manufacturer of the source.
The section on high-energy photon-emitting sources in these webpages regards TG-43 data sets which meet at least the last condition of the above-mentioned prerequisites, or data sets which originate from well tested methodology in high-energy sources and with small differences in detail of source models.
Whenever possible, additional information on the source data is provided about the methods used in MC calculation, such as cross-section libraries, spectra used, energy cut-off photon histories, etc. Moreover additional information is provided about experimental data, such as the use of specific phantom material. At least, the link to the original articles is provided. For these sources, the issue of source calibration is considered well established.
The data on high-energy sources cannot be considered conclusive. The High Energy Brachytherapy Source Dosimetry Working Group of the AAPM Therapy Physics Committee has only recently presented its recommendations concerning signle source dose-calculation parameters to be used for sources with average energy higher than 50 keV that are intended for clinical use (Li et al, Med. Phys. 34:37-40, 2007). it is the intentin of the expert group to include the final consensus data sets in this website. Therefore the present data may need to be changed (slightly) as a consequence of further co-operation with the AAPM task group. It is essential that there is an agreement on certain procedures. For example, if two or more publications are available, the consensus data set should be obtained by using the same mathematical averaging procedure. If such a procedure has been used to establish the present data for sources, it is explicitely stated with the source data. In cases where data was incomplete, similarly careful interpolation and sometimes extrapolation was applied in order to complete the data set. Such interpolated or extrapolated data is clearly indicated with the present web site information.
The section on low-energy photon emitting sources in the website regards TG-43 data sets which meet all conditions of the prerequisites. The requirements reflect the consensus view of the AAPM as to what dosimetric measurements should be made and should be available to users, before releasing the sources for routine patient treatments. When participating in brachytherapy protocols and clinical trials, institutions must use seeds that meet the prerequisistes. It is noted here that recently European initiatives were taken to establish (in addition to NIST) new standards for source strength determination for the low-energy photon emitting sources at the level of primary and secondary standards laboratories, e.g., PTB in Germany and NMi in the Netherlands. The PDSLs and SSDLs closely cooperate with NIST. The purpose is to provide easy access to European institutions to have their dosimetry equipment (e.g.: a well type chamber) calibrated for the sources under construction.
Some source data sets are still under consideration by the expert group for different reasons, such as incomplete published materials. The published data of these sources are considered as research material and are not included on the ESTRO website. However, they are available in a similar database on another website hosted at: www.uv.es/braphyqs. If the above-mentioned requirements were not fully met, but the data of a specific source were considered sufficiently accurate for clinical use by the expert group, the data set is still made available with a clear indication of its restrictions. When sufficient confidence is gained in the accuracy, completeness and reliability of such research data, the source data set will be moved to the ESTRO site. A list of sources currently under construction is found in the BRAPHYQS website
Many of the low-energy photons emitting sources, specifically most iodine-125 and palladium-103 seed sources, are not included in details, as the AAPM TG-43 task group considers them as being under study. More information on these sources can be found on http://rpc.mdanderson.org/rpc/
To better understand the TG-43 formalism the reader is referred to the original publications of the AAPM TG-43 committee.
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Nath, R., Anderson, L.L., Luxton, G., Weaver, K.E., Williamson, J.F. and Meigooni, A.S. "Dosimetry of interstitial brachytherapy sources: Report of the AAPM Radiation Therapy Committee Task Group No. 43". Med. Phys. 22, 209-234, 1995.
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Nath, R., Rivard, M.J., Coursey, B., DeWerd, L., Hanson, W., Huq, M., Ibbot, G. and Williamson, J. "Status of the American Association of Physicist in Medicine Radiation Therapy Committee´s Subcommittee on Low-Energy Interstitial Brachytherapy Source Dosimetry: Procedure for the Development of Consensus Single-Source Dose-Distributions". Med. Phys. 29, 1349, 2002.
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Rivard MJ, Coursey BM, DeWerd LA. Hanson WF, Huq MF, Ibbott GS, Mitch MG, Nath R, Williamson, J, "Update of AAPM task group no. 43 report: a revised AAPM protocol for brachytherapy dose calculations". Med Phys 2004;31:633-674, 2004.
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Dewerd L.A., Huq M.S., Das I.J., Ibbott G.S., Hanson W.F., Slowey T.W., Williamson J.F. and Coursey B.M. "Procedures for establishing and maintaining consistent air-kerma strenght standards for low-energy, photon-emitting brachytherapy sources: Recommendations of the Calibration Laboratory Accreditation Subcommittee of the American Association of Physicists in Medicine". Med. Phys. 31 675-681, 2004.
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Kouwenhoven E., Van der Laarse R. and Schaart D. "Variation in interpretation of the AAPM TG-43 geometry factors leads to unclearness in brachytherapy dosimetry". Letter to the Editor. Med. Phys. 28, 1965-1966, 2001.
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Li Z., Das R.K., DeWerd L.A., Ibott G.S., Meigooni A.S., Pérez-Catalayd J., Rivard M.J., Sloboda R.S., Williamson J.F. "Dosimetric prerequisites for routine clincial use of photon emitting brachytherapy sources with average energy higher than 50keV". Med. Phys. 34 37-40, 2007.
Helpful Link International Atomic Energy Agency(IAEA): www.iaea.org
The purpose of this section is:
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To include dosimetry data for specific applicators to indicate and assess the importance of potential effects which are currently ignored by treatment planning systems.
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To discuss the effect of phantom dimensions in simulation and experimental studies, especially for higher energy sources, and how to remove it. The issue is of interest by several members of the expert group of AAPM.
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To refer to relevant information on new developments and emerging brachytherapy technology, such as the new X-Ray miniaturized sources.
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8. List of sources
Preliminary data are provided for the sources.
SelectSeed I-125, produced by Isotron, for use in the Nucletron SeedSelectron. This source is currently used in Europe in several institutions, although consensus data according to AAPM TG43-U1 have not yet been accepted. Links to articles with experimental and Monte-Carlo works are provided.
The Yb-169 HDR 4140 source for use in afterloading has recently been published. Data is provided as being preliminary.
Data sets included in the website are for the following sources: List download
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