Transcript Slide 1

Current Topics
in Monte Carlo Treatment Planning
McGill University, Medical Physics Unit
May 3-5, 2004, Montreal, Quebec, Canada
Radovan D. Ilić, Vesna Spasić-Jokić, Petar Beličev and Miloš Dragović
Institute of nuclear sciences Vinča
TESLA Accelerator Installation
www.tesla-sc.org
www.vin.bg.ac.yu/~rasa/hopa.htm
The Monte Carlo SRNA-VOX code for
3D proton dose distribution in
voxelized geometry using CT data
GENERAL-PURPOSE MONTE CARLO
PROGRAM SRNA FOR PROTON
TRANSPORT SIMULATION
Proton therapy;
Accelerator driven system design;
Radioisotopes production for medical
applications;
Simulation of proton scatterer and degrader
shapes and composition
Radiation protection of accelerator
installations
SRNA-2KG attributes
Original author: Radovan D. Ilić, Ph.D, VINCA Institute of Nuclear
Sciences, Physics Laboratory
General Purpose: Numerical experiments for proton transport,
radiotherapy and dosimetry
Secondary particles: protons transported as the protons from source
Proton energy range: 100 keV to 250 MeV
Material Database: 279 elements: Z = 1-99, compounds and
mixtures: 181, limited by available ICRU63 cross sections data
Material geometry: 3 D – zones described by I and II order surfaces
or in 3D voxelized geometry
Program Language: Fortran 77 for Linux or Windows
SRNA-VOX MONTE CARLO CODE
Simulation model:
. Multiple scattering theory of charged particles (Moliere angular
distribution, Berger)
. Energy loss with fluctuation (ICRU49 functions of stopping power,
Vavilov's distribution with Schulek's distribution correction per all electron orbits )
. Inelastic nuclear interaction (ICRU 63, Young and Chadwik 1997)
. Compound nuclei decay (our simple and Russian MSDM models)
. CT numbers describing 3D patient’s geometry
. Correlation between CT numbers and tissue parameters:
mass-density and elemental weight
Numerical experiments setup:
. Energy range from 100 keV to 250 MeV
. Materials limited by available ICRU63 cross sections data
. Circular and rectangular proton sources in 4Pi with applied spectra
. DICOM picture and sampling region for irradiation
. Probabilities and data preparation by SRNADAT code
. 3D dose presentation on patient anatomy
Comparison of the SRNA package
Comparison of proton depth dose distribution obtained
from Monte Carlo numerical experiments by SRNA-2KG
and GEANT-3 codes
Comparison of proton depth dose distribution obtained
from Monte Carlo numerical experiments by SRNA-2K3
and GEANT-4 codes
SRNA-2KG, GEANT3, SRIM Simulation and MLFC
measurements at 205 MeV proton Indiana Univ. Cycl.
Facility, IUCF, USA
Intercomparison of the usage of computational codes in
radiation dosimetry, Bologna, Italy, July 14-16 2003
Comparison of proton depth dose distribution
obtained from Monte Carlo numerical experiments
by SRNA-2KG and GEANT-3 codes
Comparison of proton depth dose distribution
obtained from Monte Carlo numerical
experiments by SRNA-2K3 and GEANT-4 codes
Multi layer Faraday Cup (MLFC) experiments
WHY: To specify the proton beam from accelerator and
verify the quality and reproducibility of the proton beam
for the proton therapy.
WHO: Indiana University Cyclotron Facility
HOW: Monte Carlo simulation by SRIM, SRNA-2KG
and GEANT3 data compared with actual measurement
data
RECOMMENDATION: A simple test for nuclear
interaction model can be checked by MLFC. Every
Monte Carlo code to be used in charged particle therapy
should pass this test (Paganetti)
SRNA-2KG, GEANT3, SRIM Simulation
and MLFC measurements at 205 MeV proton
Indiana Univ. Cycl. Facility, USA
Mascia A.E., Schreuder N., Anferov V. August 2001
QUADOS, Bologna 2003
Uvea melanoma
A parallel beam of protons from a disk source (diameter 15 mm) impinges on a
PMMA compensator (cylindrical symmetry) and on a spherical water phantom
approximating an eye (figure 1). All elements are in vacuum. If discrete regions
are used for dose calculations (depth-dose and isodose curves), use voxels with
dimensions 0.5 x 0.5 x 0.5 mm3.
The results should be normalized to one primary proton
INTERCOMPARISON
OF THE USAGE OF COMPUTATIONAL CODES
IN RADIATION DOSIMETRY
Bologna, Italy, July 14-16 2003
Stefano Agosteo
Dipartimento Ingegneria Nucleare,Politcnico Milano, Italy
S: Fluka 2002 P3-F: srna-2kg
SRNA-VOX: Deposited proton energy in eye
50 MeV circular proton beam with 1.2 cm radius
CT data: slice thickens 0.5 cm; pixel dimension 0.081 cm
SRNA-VOX:
1E6 PROTONS; <E>=80 MeV; SPREAD=5 MeV
20 %
80 %
95%
100 %
ISTAR – proton dose
planning software
Trends in proton therapy planning:
Development of the Monte Carlo proton transport
numerical device capable of producing a therapy
plan in less than 30 minutes and
Development of clinically acceptable on-line
procedures comprising all steps necessary for
proper patient treatment.
ISTAR software solved the first of these problems
Why ISTAR ?
DUNAV – ISTAR - DJERDAP
LEPENSKI VIR LANDSCAPE
LEPENSKI VIR CULTURE
MOTHER
DANUBIUS
PROTON DATA PLANNING window
Picture Planning Data - information about the boundaries of the
space selected for simulation;
Beam geometry with fields for selection of the beam shape
(rectangular or cylindrical) and dimensions, Euler angles defining the
direction of the beam axis with respect to the selected "Beam center",
and polar and azimuthally angles of the proton emission within the
local SRNA-VOX coordinate system;
Simulation setup with fields for selection of proton energy (mean
energy and standard deviation for Gaussian distribution, or custom
defined spectrum), simulation cutoff energy, number of proton
histories and the simulation time limit. The result of these actions is
written in two files: (i) Hound.txt containing data about the defined
region, proton source and Houndsfield's numbers for all voxels of the
region; (ii) Srna.inp with the setup data for simulation.
ISTAR - Proton dose planning software
mamo proton
2D dose
eye proton
2D dose
ISTAR - Proton dose planning software
Choosing a
rectangle
around the
region for
proton dose
simulation
ISTAR - Proton dose planning software
Choice of the
first and last
slice, and
beam center
ISTAR - Proton dose planning software
Final CT and
geometry data
selection, and
making files
for set-up the
proton dose
simulation
Dose distribution in equatorial eye plane, simulated by the SRNA-VOX code, using 50
MeV protons with 1.2 MeV energy spread. The isodoses are at the values of 20, 60, 80
and 100 % of dose maximum.
20 %
60 %
80 %
100 %
in breast in central beam plane simulated by the SRNA-VOX code using 65 MeV protons with 1.5
ad. The isodoses are at the values of 20, 60, 80 and 100 % of dose maximum.
20 %
60 %
80 %
100 %
ISTAR advantages
- The software is based on the knowledge and experience acquired
in working on the SRNA
- It is capable to accept CT data for defining patient’s anatomy and
tissue composition
- A simple procedure for selecting the irradiation area and incident
proton beam parameters allow fast and comfortable calculation of
the dose distribution and visualization of it in each CT recorded
slice of the patient’s body.
- Execution time is short enough to be introduced in clinical
practice.
- The statistical error of the obtained results can be made almost
arbitrary small by simple increase of the number of the proton
histories to a few millions, without exceeding e.g. 30 min as
acceptable computer run time.
CONCLUSION
SRNA package advantages:
Enlargement of the proton energy range,
Increasing the efficiency of the implemented algorithms
in order to Decrease the time necessary for proton
transport simulation.
Motivation for ISTAR proton dose planning software
development were good results of verification of SRNA
package.
Building of the TESLA
accelerator installation
TESLA accelerator installation
(Layout)
PROGRAMS OF TESLA AI
•Construction of TAI
•Construction of the VINCY Cyclotron
•Construction of the experimental channels of TAI
•Use of TAI
•Modification of materials by ion beams
•Radiation research
•Physics of thin crystals and nanotubes
•Production of radioisotopes and radiopharmaceuticals
•Proton therapy
•Neutron research
•Physics of hadrons and electroweak interactions
•Physics of hadrons at medium energies
•Physics of electroweak interactions and medium and high
energies
pVINIS Ion Source
mVINIS Ion Source
Magnetic structure of the
VINCY Cyclotron
Channel for modification of
materials L3A
The future activities in the upgrading
of the ISTAR software assume
introduction of visualization of the
dose distribution over a 3D transparent
model of the patient body.