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Dose enhancement close to platinum implants for the 4, 6, and 10 MV stereotactic radiosurgery
Author(s) -
Cheung Joel Y. C.,
Ng Ben K. P.,
Yu K. N.
Publication year - 2004
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.1797531
Subject(s) - radiosurgery , bremsstrahlung , dosimetry , collimator , photoelectric effect , nuclear medicine , monte carlo method , photon , linear particle accelerator , materials science , irradiation , physics , medical physics , beam (structure) , optics , nuclear physics , radiation therapy , medicine , radiology , mathematics , statistics
Three photon interaction processes, namely, the photoelectric effect, Compton effect, and pair production, can occur when materials with high atomic numbers are irradiated by the high‐ and low‐energy bremsstrahlung photons from a linear accelerator. A dose enhancement, due to the photoelectric effect and pair production, near targets with platinum implants (with a high atomic number) in radiosurgery cannot be predicted by theXKnife ®radiosurgery treatment planning system. In the present work, Monte Carlo simulations using PRESTA EGS4 were employed to investigate the resulting dose enhancements from 4, 6, and 10 MV energies commonly used in the stereotactic radiosurgery system. Dose enhancements from 32% to 68% were observed close to the platinum implant for the above energies when using a 12.5 mm collimator. Comparatively higher dose enhancements were observed when using smaller collimators. It was found that this dose enhancement increased with beam energy but decreased as beam size increased.