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Comparative study of treatment dose plans after the refinement of Leksell Gamma Knife ® single‐beam dose profiles
Author(s) -
Cheung Joel Y. C.,
Ng K. P.,
Yu C. P.,
Ho Robert T. K.
Publication year - 2007
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 - 10.1118/1.2766760
Subject(s) - collimator , radiosurgery , dosimetry , nuclear medicine , beam (structure) , monte carlo method , physics , linear particle accelerator , optics , materials science , mathematics , medicine , radiation therapy , statistics , radiology
We investigated the amplification of discrepancy when using multiple shots of the same collimator size helmet, by comparing dose plans in the Leksell GammaPlan ® employing the default single‐beam dose profiles and the Monte Carlo generated single‐beam profiles. Four collimator helmets were studied. The results show that the largest amplification of discrepancy with multiple shots was found with the 8 mm collimator because of the largest discrepancy of its single‐beam dose profile. The amplification of discrepancy is significant when tumor volumes increase but insignificant when the tumor volumes are in an elongated shape. Using close shot overlapping strategy (i.e., more shots close packed together) shows no observable increase in the amplification of discrepancy. For the best quality of Leksell Gamma Knife ® radiosurgery, it is suggested that the single‐beam dose profiles should be refined, especially the 8 mm collimator, to prevent error amplification when using multiple collimator shots.