Dose Course 2018_Flipping book

Detector size: a) volume averaging

• Volume averaging is described mathematically using the profile shape and the detector geometry .

• The volume averaging correction is defined as the ratio of the absorbed dose to water at the reference point in the water phantom in the absence of the detector to the mean absorbed dose to water over the sensitive volume of the detector (still in the absence of the detector).

,

,

Sensitive volume of detector, V

=

,

,

1

Point of dose determination , ,

=

ම , ,

radiation field

Georg et al , 2 nd ESTRO Forum, Pre-meeting workshop 2013