Diapositive 1

Dose per MU formalisms:

factor-based dose calculations

ref

Reference normalisation conditions:

choice of reference depth

Reference depth in water of

10 cm

recommended irrespective of beam

quality index

– Previous recommendations

where 5 cm for BQI < 0.70

and 10 cm for BQI > 0.70

Avoids unpredictable influence of

contaminating electrons as far as

possible

– Rule of thumb: depth of

influence ~ 2·d

Dmax

or MV/3

Sjögren and Karlsson, Med, Phys, 25(6), p916, 1998

MM22,

20 MV

, SSD=100cm



10cm depth chosen for consistency in

reference depth for beam calibration and

MU calculation