Physics Bucharest 2017

Active - Optimization

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