Wahle A, Lopez JJ,
Pennington EC, Meeks SL, Braddy KC, Fox JM, Brennan
TMH, Buatti JM, Rossen JD, Sonka M:
In:
SPIE Proceedings
Volume 5029, Page 129-137, 2003
Study on the impact of vessel curvature and eccentricity of the treatment catheter in intravascular brachytherapy, as derived from 3-D models obtained by fusion of intravascular ultrasound and biplane angiography (Paper) (Images) (Links)
Abstract: Intravascular brachytherapy has shown to reduce re-occurrence of in-stent restenosis in coronary arteries. For beta radiation, application time is determined from source activity and the angiographically estimated vessel diameter. Conventionally used dosing models assume a straight vessel with the catheter centered and a constant-diameter circular cross section. Aim of this study was to compare the actual dose delivered during in-vivo intravascular brachytherapy with the target range determined from the patient's prescribed dose. Furthermore, differences in dose distribution between a simplified tubular model (STM) and a geometrically correct 3-D model (GCM) obtained from fusion between biplane angiography and intravascular ultrasound were quantified. The tissue enclosed by the segmented lumen/plaque and media/adventitia borders was simulated using a structured finite-element mesh. The beta-radiation sources were modeled as 3-D objects in their angiographically determined locations. The accumulated dose was estimated using a fixed distance function based on the patient-specific radiation parameters. For visualization, the data was converted to VRML with the accumulated doses represented by color encoding. The statistical comparison between STM and GCM models in 8 patients showed that the STM significantly underestimates the dose delivered and its variability. The analysis revealed substantial deviations from the target dose range in curved vessels.
Full Paper:
in PostScript
format
- gziped PS file, 2085 KB
for Acrobat
Reader
- PDF file, 2451 KB
Images:
Principle of In-Stent
Restenosis
- 920 columns, 600 rows, 19
KB
IVUS
Analysis and Treatment Area in Angiogram
- 497 columns, 697 rows, 289 KB
Four Layers with 72 Dosage
Points in Vessel Wall
- 920 columns,
712 rows, 77 KB
Impact
of Curvature on Dose Distribution
- 920
columns, 784 rows, 24 KB
Estimated
Doses in RCA and LAD Arteries
- 950 columns,
1175 rows, 149 KB
Links: