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THE IMPORTANCE OF THE PENUMBRA FOR SMALL SQUARE AND CIRCULAR IRRADIATION FIELDS (in German)

Journal Article · · Strahlentherapie (West Germany)
OSTI ID:4021606
The influence of geometrical penumbra on the shape of small irradiation fields was investigated by means of a computer. Special considerations were given to the /sup 60/Co unit. Maximnal deviations in radiation intensity for identical square fields lying normnally and diagonally to the irradiation beam compared to circular fields were determined. There was almost no difference in the geometrical dose distribution between square and circular fields if a field size of 1 cm/sup 2/, a source diameter of 15 mm, a source-skin distarice of 60 cm, and a source-diaphragm of 30 cm were used. A miaximal deviation of 2.4% was obtained at smnallest skin surface areas. Thus, in case of cobalt-distant irradiation, larger rectangular fields could be assembled by circular fields of 1 cm/sup 2/. (auth)
Research Organization:
Medizinische Universitat Sklinik Freiburg i. B.
NSA Number:
NSA-18-019833
OSTI ID:
4021606
Journal Information:
Strahlentherapie (West Germany), Journal Name: Strahlentherapie (West Germany) Vol. Vol: 123; ISSN STRAA
Country of Publication:
Country unknown/Code not available
Language:
German

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