A treatment planning code for hadrontherapy,ANCOD++. Faiza Bourhaleb Dipartimento di Fisica sperimentale TERA Fondation University Med 1st -Morocco Introduction ANCOD ++ Main features. ANCOD++ structure. Making an optimized treatment plan, Example of a TP. Verification with GEANT3. Perspectives. PTCOG. Catania -29- May 2002

Acknowledgment Alberto Boriano Faiza Bourhaleb Roberto Cirio Jamal Derkaoui Marco Donetti Flavio Marchetto Cristiana Peroni Camilo Sanz Freire

Optimization and treatment planning Steps before treatment CT and 3D definition of the global volume for treatment. Doctors prescription and beam info. Planning of the treatment. Treatment planning techniques: Forward planning (experience!?) Monte Carlo simulation (Time!?) Inverse planning ANCOD++ !??

Main features: C++ Version =>ANCOD++ Characteristics: Fortran Version C++ Version =>ANCOD++ Characteristics: Voxels scanning. Inverse planning =>kinetic Energies. 3D optimization => fluence values.

ANCOD++ structure Voxel CT Target Accelerator Field Energy Optimize Dose

CT Target? Interface to different CT format: DICOM CART format. Voxelplan (Heidelberg).

Target Volume extraction is done in two steps : Angles methode. Propagation methode.

Field Total volume Source Field Direction. Beams directions. Beams intersections with voxels.

Field Convertion to Lenght water equivalent. Source 21 22 23 24 25 19 20 7 8 9 17 18 4 5 6 15 16 1 2 3 10 11 12 13 14 Source lwe(9,18) Lwe at the peak position. Voxels ordering : (i,j,k) n .

Energy Table of data input : GSI . Simulation GEANT3

Experimental data of energy deposited of carbon ions in water. Bilinear interpolation of the data input to extract the desired data for a specific beam. Experimental data of energy deposited of carbon ions in water. dE/dz Z Interpolated curve for a specific beam. Ec

Optimize Iterative method used in ANCOD: Dose required, in a specific voxel, is modified in each iteration. We start our calculation of weight of a given beam without considering any correlation with the other beams, then the weight of the following beam is calculated taking into account the precedent one. Once we have the first set of the fluence values, it is necessary to iterate many times to find the fluence values satisfying the best to requirements and prescriptions.

Cutting off the non-realistic fluence values: Setting to zero negative values. Defining an upper limit on possible fluence values. Re-initialization. Iterating till an objective function defined reach the minimum.

Dose The final three dimensional dose calculation is an important step since it allows to see the results of our optimization, and to see also the finale isodose superimposed to the CT slices. The extraction of DVHs for the target volume as well the DVHs for the surrounding volume is necessary to have an overview on the whole 3D distribution in only one plot.

TP example Dose 100 40 Y X

DVH inside target DVH outside target

Verification with GEANT3 The simulation using GEANT3, for the moment, is the unique way to verify our results. For carbon ions. For protons and other heavy ions. In different materials.

Example Simulation of dose distrution of four orthogonal fields in the case of a tumor in the head.

ANCOD++ Simulation with GEANT3

100 80 ANCOD++ 60 40 20 Simulation with GEANT3

Perspectives and Future planning: To define error margins. Simultaneous optimization. Field direction optimization. Target OAR

Biological optimization.

{Thanks for your attention }

CT Target Dose Field Optimize Energy Accelerator Target Dose Field Optimize Energy