Development and validation of monte carlo dose verification system for intensity modulated radiotherapy

Y. Ishihara, Y. Narita, Tokihiro Yamamoto, T. Mizowaki, Y. Miyabe, A. Sawada, S. Yano, T. Teshima, M. Hiraoka

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We are developing a Monte Carlo (MC) based dose calculation system as a routine verification tool for four dimensional radiation therapy planning. It is of great importance of modeling multileaf collimator which induces leakage radiation, tongue-and-groove effect, beam hardening, and rounded leaf tip effect in intensity modulated radiation treatment (IMRT) field. The purpose of this study was to achieve accurate modeling inclusive of its dynamic motion behavior for the specific MLC (Millennium 120-leaf MLC, Varian) installed in our radiation treatment system. First, we generated a geometrical MLC model based on its specification given by the manufacture. The implementation was performed employing the EGS4/PRESTA MC code. Subsequently, leakage, picket fence, sliding window, pyramid, and clinical tests with a water phantom were simulated for well-commissioned 6 MV and 15 MV photon beams, respectively. Then, the above simulated results were compared with the measured data with the same condition using a solid water phantom (Gammex RMI, Middleton, WI). The simulated doses were normalized to the maximum dose in the clinical field for the clinical test while normalized to the open field of 10 x 30 cm for the other tests. The averaged differences between the simulated and the measured doses were 2.1 % (maximum 3.7 %) for the clinical test and 1.9 % for the other tests. We have achieved an accurate modeling inclusive of its dynamic motion behavior for the specific MLC. From the results, it is concluded that our modeling has a reasonable accuracy, which may be expectedly useful for a verification tool for radiation therapy planning.

Original languageEnglish (US)
Title of host publicationProceedings of the 16th EGS Users' Meeting in Japan
Pages30-39
Number of pages10
StatePublished - 2009
Externally publishedYes
Event16th EGS Users' Meeting in Japan 2009 - Tsukuba, Japan
Duration: Aug 6 2009Aug 8 2009

Other

Other16th EGS Users' Meeting in Japan 2009
CountryJapan
CityTsukuba
Period8/6/098/8/09

ASJC Scopus subject areas

  • Software

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