Binary Level-Set Shape Optimization Model and Algorithm for Volumetric Modulated Arc Therapy in Radiotherapy Treatment
Professor Li-Tien Cheng
Department of Mathematics
UC San Diego
ABSTRACT
Cancer radiotherapy, together with chemotherapy and surgery,
form the basis of modern day cancer treatment. Its treatment pro-
cess generally involves directing a high energy radiation beam at an
identied cancerous growth from dierent directions and with varying
beam shapes, durations, and intensities in order to kill the cancerous
tissues while preserving nearby healthy ones. Volumetric modulated
arc therapy comprises a recently developed setup using a full-rotation
trajectory of the beam about the patient along with a multi-leaf colli-
mator for beam shape sculpting. We introduce a variational model in
this setup for the optimization of beam shapes and intensities while
preserving certain constraints imposed by the equipment used. We
apply a binary level-set strategy to represent beam shapes and a fast
sweeping technique to satisfy beam intensity variation limits. The
result is a
ow-based shape optimization algorithm that guarantees
constraint satisfaction and energy decrease for the generation of im-
proved treatment plans in volumetric modulated arc therapy.
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