Abstract:
:A method for the calculation of absorbed dose distributions of arbitrarily shaped electron beams is presented. Isodose distributions and output factors of treatment fields can be predicted with good accuracy, without the need for any dose measurement in the actual field. A Gaussian pencil beam model is employed with two different pencil beams for each electron beam energy. The values of the parameters of the pencil beam dose distributions are determined from a set of measurements of broad beam distributions; in this way the influence of electrons scattered by the applicator walls is taken into account. The dose distribution of electrons scattered from high atomic number metal frames, which define the treatment field contour at the skin, is calculated separately and added. This calculation is based on experimentally derived data. The method has been tested for beams with 6, 10, 14 and 20 MeV electron energy. The distance between calculated and measured isodose lines with values between 10 and 90% is under 0.3 cm. The difference between calculated and measured output factors does not exceed 2%.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Bruinvis IA,Van Amstel A,Elevelt AJ,Van der Laarse Rdoi
10.1088/0031-9155/28/6/007subject
Has Abstractpub_date
1983-06-01 00:00:00pages
667-83issue
6eissn
0031-9155issn
1361-6560journal_volume
28pub_type
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