Monte-Carlo Simulation of Dynamic Arc Radiotherapy Treatments

Overview

Topic status: We're looking for students to study this topic.

The main goal of radiotherapy for the treatment of cancer is to deliver a lethal dose of ionising radiation to the perceived tumour volume while minimising the dose to surrounding healthy tissue. This is the motivation for the recent development of 3D conformal radiotherapy techniques such as Intensity Modulated Radiotherapy (IMRT) that are able to deliver dose distributions that more closely match the shape of the tumour volume and spare neighbouring healthy tissue. Intensity Modulated Radiotherapy delivery techniques are an inherently inefficient technique for delivering a 3D dose distribution. To improve efficiency dynamic rotational arc therapy delivery techniques with a linear accelerator have been developed that can significantly reduce the time to deliver a treatment while still maintaining the same level of conformality to the tumour volume. Arc therapy treatments such as Volumetric Modulated Arc Therapy (VMAT) and RapidArc are complex with the collimating jaws, multi-leaf collimators and dose rate varying during the rotation of the gantry. Independent verification of the treatment plan dosimetry is crucial to the safe and successful delivery of these treatments. Currently each patient treatment plan has to be verified by measurement in a homogeneous water equivalent phantom. The project aims to develop Monte-Carlo simulation techniques of VMAT treatments that will enable an independent verification of the patient treatment plan dosimetry.

Approaches: DOSXYZnrc is a user code of the EGSnrc Monte-Carlo code developed for calculation of radiotherapy dose distributions in phantom or patient geometries.  The latest version of the code has the ability to model the VMAT dynamic rotational arc treatments (see reference 4). The project will investigate the use of these new source models in the DOSXYZnrc Monte Carlo user code and will involve experimental work at the Princess Alexandra Hospital and computational work using the QUT high performance computing resources. The outcomes of this project will include an increased confidence in the treatments delivered to patients using the new arc therapy techniques.

References:

  • A.L Boyer, M. Goitein, A.J. Lomax and E.S. Pedroni   Radiation in the Treatment of Cancer   Physics Today, September 2002, p. 34-36
  • F. Verhaegen and J. Seuntjens  Monte-Carlo Modelling of External Radiotherapy Photon Beams, Physics in Medicine and Biology, Vol 48, p. R107-R164 (2003)
  • M. M.  Matuszak, Di Yan, I. Grills and A. Martinez   Clinical applications of volumetric modulated arc therapy  Int. J. Radiation Oncology Biol. Phys, 77, No. 2, pp. 608???616, 2010
  • J. Lobo and I. A. Popescu  Two new DOSXYZnrc sources for 4D Monte-Carlo simulations of continuously variable beam configurations with applications to RapidArc, VMAT, Tomotherapy and CyberKnife  Phys. Med. Biol. 55 4431-4443 (2010)
Study level
PhD
Supervisors
QUT
Organisational unit

Science and Engineering Faculty

Research area

Physics

Contact

Please contact the supervisor.