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Title: Dosimetric prerequisites for routine clinical use of photon emitting brachytherapy sources with average energy higher than 50 kev

Abstract

This paper presents the recommendations of the American Association of Physicists in Medicine (AAPM) and the European Society for Therapeutic Radiology and Oncology (ESTRO) on the dosimetric parameters to be characterized, and dosimetric studies to be performed to obtain them, for brachytherapy sources with average energy higher than 50 keV that are intended for routine clinical use. In addition, this document makes recommendations on procedures to be used to maintain vendor source strength calibration accuracy. These recommendations reflect the guidance of the AAPM and the ESTRO for its members, and may also be used as guidance to vendors and regulatory agencies in developing good manufacturing practices for sources used in routine clinical treatments.

Authors:
; ; ; ; ; ; ; ;  [1];  [2];  [2];  [2];  [2];  [3];  [2];  [4];  [2]
  1. Department of Radiation Oncology, University of Florida, Gainesville, Florida 32610 (United States)
  2. (United States)
  3. (Spain)
  4. (Canada)
Publication Date:
OSTI Identifier:
20853930
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 34; Journal Issue: 1; Other Information: DOI: 10.1118/1.2388155; (c) 2007 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; ACCURACY; BRACHYTHERAPY; CALIBRATION; DOSIMETRY; DRUGS; KEV RANGE 10-100; MANUFACTURING; NEOPLASMS; PHOTONS; RADIATION PROTECTION; RADIATION SOURCES; RECOMMENDATIONS

Citation Formats

Li Zuofeng, Das, Rupak K., De Werd, Larry A., Ibbott, Geoffrey S., Meigooni, Ali S., Perez-Calatayud, Jose, Rivard, Mark J., Sloboda, Ronald S., Williamson, Jeffrey F., Department of Human Oncology, University of Wisconsin, Madison, Wisconsin 53792, Accredited Dosimetry Calibration Laboratory, University of Wisconsin, Madison, Wisconsin 53706, Radiological Physics Center, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky 40536, Radiotherapy Department, Hospital La Fe, Valencia 46009, Department of Radiation Oncology, Tufts-New England Medical Center, Boston, Massachusetts 02111, Cross Cancer Institute, Edmonton, AB T6G 1Z2, and Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298. Dosimetric prerequisites for routine clinical use of photon emitting brachytherapy sources with average energy higher than 50 kev. United States: N. p., 2007. Web. doi:10.1118/1.2388155.
Li Zuofeng, Das, Rupak K., De Werd, Larry A., Ibbott, Geoffrey S., Meigooni, Ali S., Perez-Calatayud, Jose, Rivard, Mark J., Sloboda, Ronald S., Williamson, Jeffrey F., Department of Human Oncology, University of Wisconsin, Madison, Wisconsin 53792, Accredited Dosimetry Calibration Laboratory, University of Wisconsin, Madison, Wisconsin 53706, Radiological Physics Center, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky 40536, Radiotherapy Department, Hospital La Fe, Valencia 46009, Department of Radiation Oncology, Tufts-New England Medical Center, Boston, Massachusetts 02111, Cross Cancer Institute, Edmonton, AB T6G 1Z2, & Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298. Dosimetric prerequisites for routine clinical use of photon emitting brachytherapy sources with average energy higher than 50 kev. United States. doi:10.1118/1.2388155.
Li Zuofeng, Das, Rupak K., De Werd, Larry A., Ibbott, Geoffrey S., Meigooni, Ali S., Perez-Calatayud, Jose, Rivard, Mark J., Sloboda, Ronald S., Williamson, Jeffrey F., Department of Human Oncology, University of Wisconsin, Madison, Wisconsin 53792, Accredited Dosimetry Calibration Laboratory, University of Wisconsin, Madison, Wisconsin 53706, Radiological Physics Center, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky 40536, Radiotherapy Department, Hospital La Fe, Valencia 46009, Department of Radiation Oncology, Tufts-New England Medical Center, Boston, Massachusetts 02111, Cross Cancer Institute, Edmonton, AB T6G 1Z2, and Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298. Mon . "Dosimetric prerequisites for routine clinical use of photon emitting brachytherapy sources with average energy higher than 50 kev". United States. doi:10.1118/1.2388155.
@article{osti_20853930,
title = {Dosimetric prerequisites for routine clinical use of photon emitting brachytherapy sources with average energy higher than 50 kev},
author = {Li Zuofeng and Das, Rupak K. and De Werd, Larry A. and Ibbott, Geoffrey S. and Meigooni, Ali S. and Perez-Calatayud, Jose and Rivard, Mark J. and Sloboda, Ronald S. and Williamson, Jeffrey F. and Department of Human Oncology, University of Wisconsin, Madison, Wisconsin 53792 and Accredited Dosimetry Calibration Laboratory, University of Wisconsin, Madison, Wisconsin 53706 and Radiological Physics Center, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030 and Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky 40536 and Radiotherapy Department, Hospital La Fe, Valencia 46009 and Department of Radiation Oncology, Tufts-New England Medical Center, Boston, Massachusetts 02111 and Cross Cancer Institute, Edmonton, AB T6G 1Z2 and Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298},
abstractNote = {This paper presents the recommendations of the American Association of Physicists in Medicine (AAPM) and the European Society for Therapeutic Radiology and Oncology (ESTRO) on the dosimetric parameters to be characterized, and dosimetric studies to be performed to obtain them, for brachytherapy sources with average energy higher than 50 keV that are intended for routine clinical use. In addition, this document makes recommendations on procedures to be used to maintain vendor source strength calibration accuracy. These recommendations reflect the guidance of the AAPM and the ESTRO for its members, and may also be used as guidance to vendors and regulatory agencies in developing good manufacturing practices for sources used in routine clinical treatments.},
doi = {10.1118/1.2388155},
journal = {Medical Physics},
number = 1,
volume = 34,
place = {United States},
year = {Mon Jan 15 00:00:00 EST 2007},
month = {Mon Jan 15 00:00:00 EST 2007}
}
  • Purpose: Recommendations of the American Association of Physicists in Medicine (AAPM) and the European Society for Radiotherapy and Oncology (ESTRO) on dose calculations for high-energy (average energy higher than 50 keV) photon-emitting brachytherapy sources are presented, including the physical characteristics of specific {sup 192}Ir, {sup 137}Cs, and {sup 60}Co source models. Methods: This report has been prepared by the High Energy Brachytherapy Source Dosimetry (HEBD) Working Group. This report includes considerations in the application of the TG-43U1 formalism to high-energy photon-emitting sources with particular attention to phantom size effects, interpolation accuracy dependence on dose calculation grid size, and dosimetry parametermore » dependence on source active length. Results: Consensus datasets for commercially available high-energy photon sources are provided, along with recommended methods for evaluating these datasets. Recommendations on dosimetry characterization methods, mainly using experimental procedures and Monte Carlo, are established and discussed. Also included are methodological recommendations on detector choice, detector energy response characterization and phantom materials, and measurement specification methodology. Uncertainty analyses are discussed and recommendations for high-energy sources without consensus datasets are given. Conclusions: Recommended consensus datasets for high-energy sources have been derived for sources that were commercially available as of January 2010. Data are presented according to the AAPM TG-43U1 formalism, with modified interpolation and extrapolation techniques of the AAPM TG-43U1S1 report for the 2D anisotropy function and radial dose function.« less
  • This report addresses uncertainties pertaining to brachytherapy single-source dosimetry preceding clinical use. The International Organization for Standardization (ISO) Guide to the Expression of Uncertainty in Measurement (GUM) and the National Institute of Standards and Technology (NIST) Technical Note 1297 are taken as reference standards for uncertainty formalism. Uncertainties in using detectors to measure or utilizing Monte Carlo methods to estimate brachytherapy dose distributions are provided with discussion of the components intrinsic to the overall dosimetric assessment. Uncertainties provided are based on published observations and cited when available. The uncertainty propagation from the primary calibration standard through transfer to the clinicmore » for air-kerma strength is covered first. Uncertainties in each of the brachytherapy dosimetry parameters of the TG-43 formalism are then explored, ending with transfer to the clinic and recommended approaches. Dosimetric uncertainties during treatment delivery are considered briefly but are not included in the detailed analysis. For low- and high-energy brachytherapy sources of low dose rate and high dose rate, a combined dosimetric uncertainty <5% (k=1) is estimated, which is consistent with prior literature estimates. Recommendations are provided for clinical medical physicists, dosimetry investigators, and source and treatment planning system manufacturers. These recommendations include the use of the GUM and NIST reports, a requirement of constancy of manufacturer source design, dosimetry investigator guidelines, provision of the lowest uncertainty for patient treatment dosimetry, and the establishment of an action level based on dosimetric uncertainty. These recommendations reflect the guidance of the American Association of Physicists in Medicine (AAPM) and the Groupe Europeen de Curietherapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) for their members and may also be used as guidance to manufacturers and regulatory agencies in developing good manufacturing practices for sources used in routine clinical treatments.« less
  • Accurate determination of dose-rate constant ({lambda}) for interstitial brachytherapy sources emitting low-energy photons (<50 keV) has remained a challenge in radiation dosimetry because of the lack of a suitable absolute dosimeter for accurate measurement of the dose rates near these sources. Indeed, a consensus value of {lambda} taken as the arithmetic mean of the dose-rate constants determined by different research groups and dosimetry techniques has to be used at present for each source model in order to minimize the uncertainties associated with individual determinations of {lambda}. Because the dosimetric properties of a source are fundamentally determined by the characteristics ofmore » the photons emitted by the source, a new technique based on photon spectrometry was developed in this work for the determination of dose-rate constant. The photon spectrometry technique utilized a high-resolution gamma-ray spectrometer to measure source-specific photon characteristics emitted by the low-energy sources and determine their dose-rate constants based on the measured photon-energy spectra and known dose-deposition properties of mono-energetic photons in water. This technique eliminates many of the difficulties arising from detector size, the energy dependence of detector sensitivity, and the use of non-water-equivalent solid phantoms in absolute dose rate measurements. It also circumvents the uncertainties that might be associated with the source modeling in Monte Carlo simulation techniques. It was shown that the estimated overall uncertainty of the photon spectrometry technique was less than 4%, which is significantly smaller than the reported 8-10% uncertainty associated with the current thermo-luminescent dosimetry technique. In addition, the photon spectrometry technique was found to be stable and quick in {lambda} determination after initial setup and calibration. A dose-rate constant can be determined in less than two hours for each source. These features make it ideal to determine the dose-rate constant of each source model from a larger and more representative sample of actual sources and to use it as a quality assurance resource for periodic monitoring of the constancy of {lambda} for brachytherapy sources used in patient treatments.« less
  • Using Monte Carlo methods, neutron dosimetry for {sup 252}Cf Applicator Tube (AT) type medical sources available from Oak Ridge National Laboratory (ORNL) has for the first time been determined in terms of TG-43 formalism. This approach, as compared to previous {open_quotes}along-away{close_quotes} formalisms, demonstrates the relative angular independence of dose rate data, when the geometry factor has been removed. As the ORNL-made {sup 252}Cf AT type sources are considerably physically larger than most clinical sources used today, the radial dose function increases for radii less than 3.0 mm due to breakdown of the line source model. A comparison of the {supmore » 252}Cf neutron radial dose function with those for other medical sources revealed similarities with that from {sup 137}Cs. Differences with respect to previous {sup 252}Cf AT source neutron dosimetry data generally increased at increasing distances. This was attributed to differences in the various {sup 252}Cf AT source models and phantom compositions. The current status of {sup 252}Cf medical source fabrication and calibration procedures at ORNL is presented. {copyright} {ital 1999 American Association of Physicists in Medicine.}« less