Open AccessA seed specific dose kernel method for low‐energy brachytherapy dosimetry
Author(s) -
DeMarco John J.,
Solberg Timothy D.,
Agazaryan Nzhde
Publication year - 2003
Publication title -
journal of applied clinical medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.83
H-Index - 48
ISSN - 1526-9914
DOI - 10.1120/jacmp.v4i1.2543
Subject(s) - brachytherapy , monte carlo method , imaging phantom , dosimetry , kerma , kernel (algebra) , nuclear medicine , mathematics , computer science , statistics , medicine , radiation therapy , combinatorics
We describe a method for independently verifying the dose distributions from pre‐ and post‐implant brachytherapy source distributions. Monte Carlo calculations have been performed to characterize the three‐dimensional dose distribution in water phantom from a low‐energy brachytherapy source. The calculations are performed in a voxelized, Cartesian coordinate geometry and normalized based upon a separate Monte Carlo calculation for the seed specific air‐kerma strength to produce an absolute dose grid with units ofcGy hr − 1U − 1. The seed‐specific, three‐dimensional dose grid is stored as a text file for processing using a separate visual basic program. This program requires the coordinate positions of each seed in the pre‐ or post‐plan and sums the kernel file for a three‐dimensional composite dose distribution. A kernel matrix size of 81 × 81 × 81 with a voxel size of 1.0 × 1.0 × 1.0 mm 3was chosen as a compromise between calculation time, kernel size, and truncation of the stored dose distribution as a function of radial distance from the midpoint of the seed. Good agreement is achieved for a representative pre‐ and post‐plan comparison versus a commercial implementation of the TG‐43 brachytherapy dosimetry protocol. © 2003 American College of Medical Physics. PACS number(s): 87.53.‐j, 87.52.‐g