Current Topics in Monte Carlo Treatment Planning

McGill University, Medical Physics UnitMay 3-5, 2004, Montreal, Quebec, Canada

The Monte Carlo SRNA-VOX code for 3D proton dose distribution in

voxelized geometry using CT data

Radovan D. Ilić, Vesna Spasić-Jokić, Petar Beličev and Miloš Dragović

Institute of nuclear sciences VinčaTESLA Accelerator Installation

www.tesla-sc.orgwww.vin.bg.ac.yu/~rasa/hopa.htm

GENERAL-PURPOSE MONTE CARLO GENERAL-PURPOSE MONTE CARLO PROGRAM SRNA FOR PROTON PROGRAM SRNA FOR PROTON

TRANSPORT SIMULATIONTRANSPORT 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 attributesSRNA-2KG attributes 

Original author: Radovan D. Ilić, Ph.D, VINCA Institute of Nuclear Sciences, Physics LaboratoryGeneral Purpose: Numerical experiments for proton transport, radiotherapy and dosimetrySecondary particles: protons transported as the protons from sourceProton energy range: 100 keV to 250 MeVMaterial Database: 279 elements: Z = 1-99, compounds and mixtures: 181, limited by available ICRU63 cross sections dataMaterial geometry: 3 D – zones described by I and II order surfaces or in 3D voxelized geometryProgram 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 packageComparison of the SRNA package

ComparisonComparison of proton depth dose distribution obtained of proton depth dose distribution obtained from Monte Carlo numerical experiments by SRNA-2KG from Monte Carlo numerical experiments by SRNA-2KG and GEANT-3 codesand GEANT-3 codesComparisonComparison of proton depth dose distribution obtained of proton depth dose distribution obtained from Monte Carlo numerical experiments by SRNA-2K3 from Monte Carlo numerical experiments by SRNA-2K3 and GEANT-4 codesand GEANT-4 codesSRNA-2KG, GEANT3, SRIM Simulation and SRNA-2KG, GEANT3, SRIM Simulation and MLFC MLFC measurements measurements at 205 MeV proton Indiana Univ. Cycl. at 205 MeV proton Indiana Univ. Cycl. Facility, IUCF, USAFacility, IUCF, USAIntercomparison of the usage of computational codes in radiation dosimetry, Bologna, Italy, July 14-16 2003

  

Comparison of proton depth dose distributionComparison of proton depth dose distribution obtained from Monte Carlo numerical experimentsobtained from Monte Carlo numerical experiments

by SRNA-2KG and GEANT-3 codesby SRNA-2KG and GEANT-3 codes

Comparison of proton depth dose distributionComparison of proton depth dose distribution obtained from Monte Carlo numerical obtained from Monte Carlo numerical

experiments by SRNA-2K3 and GEANT-4 codesexperiments 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 FacilityHOW: Monte Carlo simulation by SRIM, SRNA-2KG and GEANT3 data compared with actual measurement dataRECOMMENDATION: 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 SimulationSRNA-2KG, GEANT3, SRIM Simulationand MLFC measurements at 205 MeV protonand MLFC measurements at 205 MeV proton

Indiana Univ. Cycl. Facility, USAIndiana Univ. Cycl. Facility, USA

Mascia A.E., Schreuder N., Anferov V. August 2001Mascia A.E., Schreuder N., Anferov V. August 2001

QUADOS, Bologna 2003Uvea 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 DOSIMETRYBologna, Italy, July 14-16 2003

Stefano AgosteoDipartimento 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 radiusCT 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 ISTAR – proton dose planning softwareplanning 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 andDevelopment 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 - DJERDAPDUNAV – ISTAR - DJERDAP

LEPENSKI VIR LANDSCAPELEPENSKI VIR LANDSCAPE

LEPENSKI VIR CULTURELEPENSKI VIR CULTURE

MOTHER DANUBIUSMOTHER DANUBIUS

PROTON DATA PLANNING windowPROTON 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.

mamo proton 2D dose

eye proton 2D dose

ISTAR - Proton dose planning software

ISTAR - Proton dose planning software

Choosing a rectangle

around the region for

proton dose simulation

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

ISTAR - Proton dose planning software

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 %

Dose distribution in breast in central beam plane simulated by the SRNA-VOX code using 65 MeV protons with 1.5 MeV energy spread. The isodoses are at the values of 20, 60, 80 and 100 % of dose maximum.

20 %

60 %

80 %

100 %

ISTAR advantagesISTAR 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.

CONCLUSIONCONCLUSION

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 Building of the TESLA accelerator installationaccelerator installation

TESLA accelerator installationTESLA accelerator installation (Layout)(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 SourcepVINIS Ion Source

mVINIS Ion SourcemVINIS Ion Source

Magnetic structure of the Magnetic structure of the VINCY CyclotronVINCY Cyclotron

Channel for modification of Channel for modification of materials L3Amaterials 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.