1203 / 1416
0
Small Bowel: Dose / Volume distribution in 31
patientsxx
treated to mean target doses of 72.3 Gy(RBE) (range:
64-76)
Volume
mean (cc)
range (cc)
V 5 (24 pts.)
86.5
2.0 - 238
V20 (24 pts.)
45.1
0.2 - 151
V30 (22 pts.)
35.5
0.1 - 120
V40 (20 pts.)
27.5
0.2 - 89.0
V50 (19 pts.)
17.7
0.2 - 59.0
V60 (17 pts.)
7.6
0.4 - 29.0
V70 (12 pts.)
2.4
0.1 - 11.0
Volume
mean (cc)
range (cc)
V75 (10 pts.)
1.9
<0.1 - 3.1
V80 (4 pts.)
0.2
<0.1 - 0.5
XX = volume definition and analysis based on initial planning CT
Results at PSI
(Schneider et al., 2010, ASTRO presentation)
Using the sharp dose fall-off, proton therapy can deliver
high doses to posterior bowel walls, yet only moderate
doses to anterior bowel walls
Small bowel can tolerate well doses > 60 Gy(RBE), as long as
not circumferenPal