Monte Carlo dose verification for intensity-modulated arc therapy. Phys Med Biol 2001 Sep;46(9):2269-82
Date
10/03/2001Pubmed ID
11580168DOI
10.1088/0031-9155/46/9/301Scopus ID
2-s2.0-0034827572 (requires institutional sign-in at Scopus site) 37 CitationsAbstract
Intensity-modulated arc therapy (IMAT), a technique which combines beam rotation and dynamic multileaf collimation, has been implemented in our clinic. Dosimetric errors can be created by the inability of the planning system to accurately account for the effects of tissue inhomogeneities and physical characteristics of the multileaf collimator (MLC). The objective of this study is to explore the use of Monte Carlo (MC) simulation for IMAT dose verification. The BEAM/DOSXYZ Monte Carlo system was implemented to perform dose verification for the IMAT treatment. The implementation includes the simulation of the linac head/MLC (Elekta SL20), the conversion of patient CT images and beam arrangement for 3D dose calculation, the calculation of gantry rotation and leaf motion by a series of static beams and the development of software to automate the entire MC process. The MC calculations were verified by measurements for conventional beam settings. The agreement was within 2%. The IMAT dose distributions generated by a commercial forward planning system (RenderPlan. Elekta) were compared with those calculated by the MC package. For the cases studied, discrepancies of over 10% were found between the MC and the RenderPlan dose calculations. These discrepancies were due in part to the inaccurate dose calculation of the RenderPlan system. The computation time for the IMAT MC calculation was in the range of 20-80 min on 15 Pentium-Ill computers. The MC method was also useful in verifying the beam apertures used in the IMAT treatments.
Author List
Li XA, Ma L, Naqvi S, Shih R, Yu CMESH terms used to index this publication - Major topics in bold
Dose-Response Relationship, RadiationHumans
Male
Monte Carlo Method
Phantoms, Imaging
Prostate
Prostatic Neoplasms
Radiometry
Radiotherapy Planning, Computer-Assisted
Radiotherapy, Conformal
Software