Air-kerma strength determination of a {sup 169}Yb high dose rate brachytherapy source
- University of Wisconsin Medical Radiation Research Center, Madison, Wisconsin 53706 (United States)
The increased demand for high dose rate (HDR) brachytherapy as an alternative to external beam radiotherapy has led to the introduction of a HDR brachytherapy isotope {sup 169}Yb. This source offers a dose rate similar to {sup 192}Ir HDR sources, at about one fourth the effective photon energy. This work presents the calibration of this source in terms of air-kerma strength, based on an adaptation of the current, National Institute of Standards and Technology traceable, in air measurement technique currently used for {sup 192}Ir HDR sources. Several additional measurement correction factors were required, including corrections for air scatter, air attenuation, and ion recombination. A new method is introduced for determining the ion chamber calibration coefficient N{sub k}{sup 169}{sup Yb}. An uncertainty analysis was also performed, indicating an overall measurement expanded uncertainty in the air-kerma strength (k=2) of 2.2%.
- OSTI ID:
- 21120906
- Journal Information:
- Medical Physics, Vol. 35, Issue 9; Other Information: DOI: 10.1118/1.2964094; (c) 2008 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-2405
- Country of Publication:
- United States
- Language:
- English
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