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SFUD
(Single field uniform dose optimization): intensities of pencil beams of each
beam (number of particles per spot distribution) are optimized individually to deliver
a uniform beam dose to the target volume and minimize the dose outside
IMPT
(Intensity-modulated particle therapy): intensities of all beams are optimized
simultaneously -> uses pencil beams or spots (from all beams) with individually
optimized weights to balance the dose and dose-volume objectives of normal tissues
and target volumes
+
Flexibility
of arbitrarily setting nonuniform intensities of pencil beams of a
sequence of energies of multiple beams incident from different directions
-
Intensities of spots (and dose distribution) per beam can be highly inhomogeneous -
> Higher
sensitivity
to range, set-up and treatment delivery uncertainties
Active - Optimization