Zeiss INTRABEAM, Инструкция по эксплуатации

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Operation INTRABEAM Water Phantom
Version 6.2
Page 62 G-30-1767-en
Water phantom procedure for depth dose curve measurements using a
flat or surface applicator
The applicators are designed for radiation treatment on the surface (surface
applicator) and at a depth of 5 mm (flat applicator). In the first case, the dose
rate must be measured on the surface of the applicator. The ionization
chamber itself is not watertight, so it has to be maintained watertight in a
measuring chamber. Because of the wall of the measuring chamber, the ap-
plicators cannot be placed flat directly in the ionization chamber.
This is a problem similar to that of spherical applicators when the dose rate
has to be measured there on the applicator surface. For this reason, an adjust-
ment function must be applied to the depth dose curve or the transfer func-
tion to extrapolate the data to the surface of the spherical applicators. The
same applies to the flat or surface applicators. Therefore, in order to simulate
the clinical conditions, the measuring chamber should touch the surface of
the applicator placed in a water/air interface completely as shown in the illus-
tration below.
Chamber holder making contact with the surface of the
applicator placed flush in water (air-water interface)