70 likes | 231 Views
CIEG: Incorporating Interfraction Motion in IMRT Treatment Plan ning. Chunhua Men Joint work with H. Edwin Romeijn , James F. Dempsey University of Florida. Radiation Therapy. Beams of radiation pass through a patient, killing normal and cancerous cells
E N D
CIEG: Incorporating Interfraction Motion in IMRT Treatment Planning Chunhua Men Joint work with H. Edwin Romeijn, James F. Dempsey University of Florida CISE - SDSC, CA
Radiation Therapy • Beams of radiation pass through a patient, killing normal and cancerous cells • The goal is to design a treatment plan that delivers a prescribed dose to targets, while sparing critical structures • Multiple beams are used, whose intersection provides a high dose, whereas regions covered by a single beam or only a few beams receive much lower radiation doses CISE - SDSC, CA
Intensity Modulated Radiation Therapy (IMRT) • We consider a technique called Intensity Modulated Radiation Therapy. • Each beam is considered to be decomposed into a matrix of beamlets (bixels) • Traditionally, we search for an optimal radiation intensity for each of the beamlets. The problem of finding an optimal intensity profile for each beam is called Fluence Map Optimization (FMO) • A solution is evaluated by considering the dose distribution over a discretization of the irradiated area into a finite number of cubes (voxels) CISE - SDSC, CA
Current Treatment Plan • The IMRT treatment plan are not delivered in a single session, but rather as a sequence of daily treatments over a period of 5-7 weeks • Patient needs to be set up at the linear accelerator for each fraction. This cannot be done with complete precision • Setup errors mean that the actual delivered dose distribution is different from the planned/optimized one on each day of the treatment! • Changes between fractions are called interfraction motion • However, the current treatment plan optimization models do not take into account the interfraction motion CISE - SDSC, CA
The Challenge of the Optimization Model • The current optimization models that are used to find treatment plan are already challenging large-scale optimization problems • Models that explicitly account for the motion may quickly become intractable • This inhibits the clinical transition to more advanced used of radiation therapy that is based on more frequent imaging and re-optimization of the treatment plan, ideally on the daily basis – or even in real-time, i.e., during treatment CISE - SDSC, CA
The Goals of CISE • We would like to use the facilities of the SDSC to test our models which are of increasing size and difficulty, based on a growing level of detail in the representation of the uncertainties, i.e., patient motion • We expect that the facilities of the SDSC will provide us with the ability to handle large-scale datasets and solve very large-scale modes CISE - SDSC, CA
The Goals of the Workshop • During this workshop, we expect to • Set up basic concept/idea about the cyberinfrastructure • Learn about the available cyberinfrastructure tools/facilities that will help us achieve the goals of our project CISE - SDSC, CA