AbstractID: 7264 Title: Use of THERAPLAN Plus Treatment Planning System for Quantitative Analysis in
Endovascular Brachytherapy
Purpose: The purpose of this work was to evaluate the THERAPLAN Plus Image Based Brachytherapy
System for calculating dose distributions for intravascular radiotherapy.
Materials and Methods: THERAPLAN Plus Image Based Brachytherapy software was used to capture
IVUS images of the coronary arteries and to perform 3D dose calculations. The software had to be
modified to allow dose calculation and display at distances closer to the source than for standard
brachytherapy applications. A Sr-90 source from BetaCath device (Novoste) was used. It was modeled in
THERAPLAN Plus as a linear source with the anisotropy function calculated by Wang and Li using Monte
Carlo (Med. Phys. 27, 2528., 2000).
Results: The overall agreement between the dose rate matrix calculated by THERAPLAN Plus for a single
Sr-90 source and Wang and Li data was within 5% at distances greater than 0.5 mm from the source.
Larger disagreements were observed at distances less than 0.5 mm from the source. Treatment plans for a
train of 12 sources were generated. The dose delivered to various parts of the arterial wall was evaluated in
terms of isodose distribution on transverse ultrasound images as well as in 3D. Dose volume histograms,
DVH, were generated to evaluate the dose coverage for different parts of arterial wall. THERAPLAN Plus
has proven to be a useful tool for quantitative evaluation of the treatments. In addition, this study indicates
a possible need for custom treatment planning based on individual vessel anatomy.
Acknowledgment: This research has been partially supported by MDS Nordion and Novoste corporations.