Dose Course 2018_Flipping book

Small fields: relative dosimetry - field size factor, S cp

Minimise energy/field size dependence

An approximation to account for the influence of spectral changes between the 10cm  10cm and a smaller field (e.g. 4cm  4cm) on detector response would be to cross-calibrate the small detector against a medium size detector in an intermediate field (smaller than the reference field of 10cm × 10cm);

This is referred to as ‘ daisy-chaining’ by Dietrich & Sherouse MedPhys 38(7), 2011

( ) ( ) M A M A M  IC

( ) ( ) ref int

AM A

( )

diode

AS 

cp

diode

IC

int