Modern Bt Techniques - Florence 2016

693 / 1840

Forward Planning / Optimization
Geometrical “Optimisation”, GO
The dwell time of the source at a dwell position is
inversely proportional to the dose contribution of
neighboring source dwell positions.
Points a, b, c, … are source dwell positions (SDPs).
...
1 1 1
2
3
3
2
2
2
2
1
1 







⋅ + 






⋅ + 






⋅ ≈
b b b
b
r
T
r
T
r
T D
Implant /
Catheters 1
b
1
2






=
b
b D
T
1
: If D b large →
Tb small
Ti equal to 1 at start, iteratively calculated
until nothing changes anymore.
2
3