AbstractID: 8770 Title: Dosimetric Effects Of Seed Orientation And Anisotropy Function
In High-Energy Photon Emitting Sources.
The effect of seed angular orientation and anisotropy function on the dose distribution in a given target volume implanted
with non-radioactive high-energy photon emitting sources is investigated. A method for incorporating the anisotropy
function into a brachytherapy dose calculation algorithm is first developed. The seeds are then allowed to exhibit a
random angular orientation to simulate a typical implant situation. The point source approximation is found to largely overestimate the delivered dose compared to an actual source model calculation. However, random angular orientations of the
seeds do not appear to have a significant effect on the dose distribution. Tissues in close proximity to the seeds
experience at most 2% variation in dose between fixed and random seed orientations distributions.
This work is supported in part by a grant from the Alberta Heritage Foundation for Medical Research.