A dose-point-kernel model for a low energy gamma-emitting stent in a heterogeneous medium.
A computer dose model for a low energy gamma-emitting stent in a heterogeneous medium is described. The method is based on the Sievert model which is adapted to the dose-point-kernel (DPK) model to compute the dose distribution about filtered gamma sources (Sievert-DPK model). The new gamma stent model can take into account effects such as the metallic wire attenuation and the presence of dense calcified plaque in a stented artery. The Sievert-DPK model is tested against numerical simulations around cylindrical shell sources with dimensions comparable to those of a stent using a Monte Carlo transport code. For low energy gamma sources (Cs-131 and Pd-103), it is shown that the Sievert-DPK model is consistent with the Monte Carlo results to about 5%-10% for distances up to 5 mm from the cylindrical surface and 2.5 mm beyond the cylinder edges. These results indicate that the Sievert-DPK model may be useful to predict the dose in intravascular therapy applications for heterogeneous systems consisting of soft tissue, metal and dense plaque.
Janicki
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C
Centre Hospitalier de l'Université de Montréal, Dept. de médecine nucléaire, Québec, Canada. cjanicki@total.net
Duggan
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DM
Rahdert
D A
DA
D015906:Angioplasty, Balloon, Coronary / Q000379:methods*; D002138:Calibration; D002588:Cesium Radioisotopes / Q000627:therapeutic use; D005720:Gamma Rays; D015233:Models, Statistical; D009010:Monte Carlo Method; D010165:Palladium / Q000627:therapeutic use; D019047:Phantoms, Imaging; D011868:Radioisotopes / Q000627:therapeutic use; D011874:Radiometry / Q000379:methods*; D015203:Reproducibility of Results; D012984:Software; D014867:Water
D002588:Cesium Radioisotopes; D011868:Radioisotopes; D014867:Water; D010165:Palladium