Dose per MU formalisms: factor-based dose calculations
Isocentric formalism: dose per meterset NOT at isocentre (on CAX)
2
eqsq d,
eqsq ,
p
eqsq
c
ref
ref
d
,
,
;
,
d SSD
SAD
d s TPR
s
S cS
M
d cD
M
SSD dsD
d
Scaling energy fluence from
that at isocentre to that at the
calculation point not at SAD
On the assumption that phantom
scatter ratios are independent of
SSD
The field size used is that at the
calculation point