electron beam dose distribution in the presence of non-uniform magnetic field

Authors

mohamad javad tahmasebi-birgani department of medical physics, jundishapuruniversity of medical sciences, ahvaz, iran

mohamad reza bayatiani radiotherapy and medical physics department of arak university of medical sciences&khansari hospital, arak, iran

fatemeh seif radiotherapy and medical physics department of arak university of medical sciences&khansari hospital, arak, iran

mansur zabihzadeh department of medical physics, jundishapuruniversity of medical sciences, ahvaz, iran

abstract

introduction magnetic fields are capable of altering the trajectory of electron beams andcan be used in radiation therapy.theaim of this study was to produce regions with dose enhancement and reduction in the medium. materials and methods the ndfeb permanent magnets were arranged on the electron applicator in several configurations. then, after the passage of the electron beams (9 and 15 mev varian 2100c/d) through the non-uniform magnetic field, the percentage depth dose(pdds) on central axis and dose profiles in three depths for each energy were measured in a 3d water phantom. results for all magnet arrangements and for two different energies, the surface dose increment and shift in depth of maximum dose (dmax) were observed. in addition, the pattern of dose distribution in buildup region was changed. measurement of dose profile showed dose localization and spreading in some other regions. conclusion the results of this study confirms that using magnetic field can alter the dose deposition patterns and as a result can produce dose enhancement as well as dose reduction in the medium using high-energy electron beams. these effects provide dose distribution with arbitrary shapes for use in radiation therapy.

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Journal title:
iranian journal of medical physics

جلد ۱۱، شماره ۱، صفحات ۱۹۵-۲۰۴

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