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Author Carlone, Marco ♦ Keller, Harald ♦ Rezaee, Mohammad ♦ Tadic, Tony ♦ Jaffray, David
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ISOTOPES AND RADIATION SOURCES ♦ APPLIED LIFE SCIENCES ♦ COBALT 60 ♦ DEPTH DOSE DISTRIBUTIONS ♦ MAGNETIC FIELDS ♦ PEAKS ♦ PHYSICAL PROPERTIES
Abstract Purpose: The surface dose in radiotherapy is subject to the physical properties of the radiation beam and collimator. The purpose of this work is to investigate the manipulation of surface dose using magnetic fields produced with a resistive magnet. Better understanding of the feasibility and mechanisms of altered surface dose could have important clinical applications where the surface dose must be increased for therapeutic goals, or reduced to enhance the therapeutic benefit. Methods: A resistive magnet capable of generating a peak magnetic field up to 0.24 T was integrated with a cobalt treatment unit. The magnetic fringe field of the magnet was small due to the self-shielding built within the magnet. The magnetic field at the beam collimation jaws of the cobalt irradiator was less than 10 G. The surface dose and depth dose were measured for varying magnetic field strengths. Results: The resistive magnet was able to alter the dose in the buildup region of the {sup 60}Co depth dose significantly, and the magnitude of dose enhancement was directly related to the strength of the longitudinal magnetic field. Peak magnetic fields as low as 0.08 T were able to affect the surface dose. At a peak field of 0.24 T, the authors measured a surface dose enhancement of 2.8-fold. Conclusions: Surface dose enhancement using resistive magnets is feasible. Further experimental study is needed to understand the origin of the scattered electrons that contribute to the increase in surface dose.
ISSN 00942405
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-06-15
Publisher Place United States
Journal Medical Physics
Volume Number 43
Issue Number 6


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