Implementation of Monte Carlo Dose calculation for CyberKnife treatment planning
- 1 February 2008
- journal article
- Published by IOP Publishing in Journal of Physics: Conference Series
- Vol. 102 (1), 012016
- https://doi.org/10.1088/1742-6596/102/1/012016
Abstract
Accurate dose calculation is essential to advanced stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) especially for treatment planning involving heterogeneous patient anatomy. This paper describes the implementation of a fast Monte Carlo dose calculation algorithm in SRS/SRT treatment planning for the CyberKnife® SRS/SRT system. A superposition Monte Carlo algorithm is developed for this application. Photon mean free paths and interaction types for different materials and energies as well as the tracks of secondary electrons are pre-simulated using the MCSIM system. Photon interaction forcing and splitting are applied to the source photons in the patient calculation and the pre-simulated electron tracks are repeated with proper corrections based on the tissue density and electron stopping powers. Electron energy is deposited along the tracks and accumulated in the simulation geometry. Scattered and bremsstrahlung photons are transported, after applying the Russian roulette technique, in the same way as the primary photons. Dose calculations are compared with full Monte Carlo simulations performed using EGS4/MCSIM and the CyberKnife treatment planning system (TPS) for lung, head & neck and liver treatments. Comparisons with full Monte Carlo simulations show excellent agreement (within 0.5%). More than 10% differences in the target dose are found between Monte Carlo simulations and the CyberKnife TPS for SRS/SRT lung treatment while negligible differences are shown in head and neck and liver for the cases investigated. The calculation time using our superposition Monte Carlo algorithm is reduced up to 62 times (46 times on average for 10 typical clinical cases) compared to full Monte Carlo simulations. SRS/SRT dose distributions calculated by simple dose algorithms may be significantly overestimated for small lung target volumes, which can be improved by accurate Monte Carlo dose calculations.This publication has 17 references indexed in Scilit:
- Investigation of optimal beam margins for stereotactic radiotherapy of lung-cancer using Monte Carlo dose calculationsPhysics in Medicine & Biology, 2007
- Monte Carlo treatment planning for photon and electron beamsRadiation Physics and Chemistry, 2006
- Dosimetric characteristics of a new unshielded silicon diode and its application in clinical photon and electron beamsMedical Physics, 2005
- Clinical implementation of a Monte Carlo treatment planning systemMedical Physics, 1999
- Characterization of computer simulated radiotherapy beams for Monte-Carlo treatment planningRadiation Physics and Chemistry, 1998
- Accurate characterization of Monte Carlo calculated electron beams for radiotherapyMedical Physics, 1997
- BEAM: A Monte Carlo code to simulate radiotherapy treatment unitsMedical Physics, 1995
- Monte Carlo techniques in medical radiation physicsPhysics in Medicine & Biology, 1991
- Applications of the Monte Carlo Method in RadiotherapyPublished by Elsevier BV ,1990
- Monte Carlo Techniques of Electron and Photon Transport for Radiation DosimetryPublished by Elsevier BV ,1990