Estimating the actual dose delivered by intravascular coronary brachytherapy using geometrically correct 3D modeling
| Autor: | K.C. Braddy, Andreas Wahle, James D. Rossen, James M. Fox, Sanford L. Meeks, Theresa M. H. Brennan, John J. Lopez, Edward C. Pennington, John M. Buatti, Milan Sonka |
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| Rok vydání: | 2003 |
| Předmět: |
medicine.medical_specialty
medicine.diagnostic_test business.industry medicine.medical_treatment Brachytherapy Lumen (anatomy) 3D modeling medicine.disease Coronary arteries Cross section (geometry) medicine.anatomical_structure Restenosis Intravascular ultrasound Angiography medicine Radiology business Nuclear medicine |
| Zdroj: | Medical Imaging: Image-Guided Procedures |
| ISSN: | 0277-786X |
| DOI: | 10.1117/12.480218 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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