An optimization tool for conformal radiation
therapy
Jinho Lim, Matthew Earl, Michael C. Ferris, David M. Shepard, and Stephen J. Wright
University of Wisconsin - Madison
In recent years, significant advances have been made in imaging
technologies and in the linear accelerators used to deliver radiation
therapy to cancer patients. These advances make it possible to
deliver more precise and effective treatment plans that provide a high
probability of tumor control while minimizing the damage to normal
tissue. Optimization formulations and algorithms are proving to be
important tools in developing such plans. In this paper, we introduce
a tool for the optimization of three-dimensional conformal radiation
therapy. The tool simultaneous optimizes the beam configuration and
the beam weights. In addition, the optimization model includes wedge
filters, which are often placed in front of the beam to produce a
gradient in the beam intensity across the aperture. The tool optimizes
both the wedge angle and wedge orientation. The paper describes the
formulation and solution of the optimization. The optimized dose
distribution can be evaluated with the assistance of a visualization
tool that displays the dose contours in relation to the target
(tumor), the surrounding normal tissue, and any nearby critical
structures. Our results show that it is possible to deliver a
treatment plan that closely matches the clinician's prescription using
beams from relatively few angles.
This talk was given at the 2nd Annual McMaster Optimization
Conference Theory and Application (MOPTA) held at McMaster
University, Hamilton, Ontario, Canada on August 3, 2002.