AbstractID: 7842 Title: Dosimetry of the Sr/Y sources train of the Novoste beta-cath
system
The radiation dosimery of the investigated sources are 30 and 40 mm Sr/Y
sources train of the beta-cath systems produced by Novoste Corporation.
The active source train consists of a train of 12 or 16 miniature cylindrical
sealed Sr/Y sources and two, one proximal and one distal, gold radiopaque
markers. The dosimetry was determined using three independent methods:
(a) The radiochromic film dosimetry, (b) The micro MOSFET detector
measurement, and (c) Monte Carlo simulations. The calibrations of the
measurements were obtained by exposures with an ophthalmic applicator
and x-ray sources. The uncertainties were analyzed. The theoretical
simulation of the catheter-based system is achieved by using MCNP Monte
Carlo code. The data of both measured and calculated results are converted
to dose rate in water. Comparisons indicate that the measured and calculated
dosimetry is in agreement of 15% in the system treatment distance of 1 mm
to 5 mm. The dose rate at 2 mm from the center of the source train is also in
agreement with the system radiation output given by the manufacture and
with the measurement readout from the well chamber traceable to NIST. In
addition, the study characterizes the radiation field around Sr/Y sources in
water. The depth dose and the dosimetry of the step treatment were studied
and can be used to calculate the dose to the vessel wall from the center of the
source train.