Dose volume effect for acute bowel,
impact of V40 and V15
V40
< 170 cc
V45
< 100 cc
V50
< 33 cc
Incidence of toxicity drops from 21% to 3%
when:
175 prostate cancer patients
3D CRT or IMRT
12% acute Gr 2-3 bowel toxicity
153 rectal cancer patients
3-field EBRT with concomitant
chemotherapy
21 % acute G3 diarrhea
Impact of
V15
on diarrhea seemed strongest
V15 should however be seen as a geometrical
surrogate for the high dose volumes and not used
alone for optimizing IMRT dose distribution
Fiorino
IJROBP, 2009
Robertson
IJROBP, 201