Dear Ayaz

Thank you very much for your kind information. I will check all web links send by you and will try yo do my best.

Thanking you once again.

Geant4 event-level parallelism is based on a master-worker model in which a set of threads (the workers) are spawned and are responsible for the simulation of events, while the steering and control of the simulation is given to an additional entity (the master).

http://geant4.web.cern.ch/geant4/UserDocumentation/UsersGuides/ForToolkitDeveloper/html/ch02s14.html

Dear Ayaz

Yes, I read it. Thank you very much for your nice cooperation and help.

I also read the following nice article:-

Implementation of a new Monte Carlo simulation tool for the development of a proton therapy beam line and verification of the related dose distributions

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=1352218&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D1352218

http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=1352215

A Geant4-based Python/C++ simulation and coding framework, which has been for simulation.

www.science.gov/topicpages/g/geant4-based+simulation+software.html

A method to evaluate the dosimetric accuracy of volumetric modulated arc therapy (VMAT) treatment plans, generated with the MONACO™ (version 3.0) treatment planning system in realistic CT-data with an independent Geant4 based dose calculation algorithm is presented. Therefore a model of an Elekta Synergy linear accelerator treatment head with an MLCi2 multileaf collimator was implemented in Geant4. The time dependent linear accelerator components were modeled by importing either logfiles of an actual plan delivery or a DICOM-RT plan sequence. Absolute dose calibration, depending on a reference measurement, was applied. The MONACO as well as the Geant4 treatment head model was commissioned with lateral profiles and depth dose curves of square fields in water and with film measurements in inhomogeneous phantoms. A VMAT treatment plan for a patient with a thoracic tumor and a VMAT treatment plan of a patient, who received treatment in the thoracic spine region including metallic implants, were used for evaluation. MONACO, as well as Geant4, depth dose curves and lateral profiles of square fields had a mean local gamma (2%, 2mm) tolerance criteria agreement of more than 95% for all fields. Film measurements in inhomogeneous phantoms with a global gamma of (3%, 3mm) showed a pass rate above 95% in all voxels receiving more than 25% of the maximum dose. A dose-volume-histogram comparison of the VMAT patient treatment plans showed mean deviations between Geant4 and MONACO of -0.2% (first patient) and 2.0% (second patient) for the PTVs and (0.5±1.0)% and (1.4±1.1)% for the organs at risk in relation to the prescription dose. The presented method can be used to validate VMAT dose distributions generated by a large number of small segments in regions with high electron density gradients. The MONACO dose distributions showed good agreement with Geant4 and film measurements within the simulation and measurement errors. PMID:22921843

By the authors:- Fleckenstein, Jens; Jahnke, Lennart; Lohr, Frank; Wenz, Frederik; Hesser, Jürgen, 2013-02-01

http://www.ncbi.nlm.nih.gov/pubmed/22921843