The 90-day coronary vascular response to 90Y-β particle-emitting stents in the canine model
| Autor: | Gerti Tashko, Renu Virmani, Allen J. Taylor, William L. Sweet, Patrick D. Gorman, Craig Hudak, Andrew Farb |
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| Rok vydání: | 2000 |
| Předmět: |
Cancer Research
medicine.medical_specialty medicine.medical_treatment Brachytherapy Urology Revascularization Random Allocation Dogs Double-Blind Method Restenosis Carnivora medicine Animals Yttrium Radioisotopes Radiology Nuclear Medicine and imaging Adverse effect Radiation biology business.industry Fissipedia Stent Dose-Response Relationship Radiation medicine.disease biology.organism_classification Coronary Vessels Surgery Radiation therapy Stenosis Oncology Stents Tunica Intima business Phosphorus Radioisotopes Half-Life |
| Zdroj: | International Journal of Radiation Oncology*Biology*Physics. 46:1019-1024 |
| ISSN: | 0360-3016 |
| DOI: | 10.1016/s0360-3016(99)00415-0 |
| Popis: | Purpose: Long-term preclinical studies using continuous, low-dose-rate vascular brachytherapy with 32 P β-emitting stents have yielded largely disappointing results. In contrast, a shorter half-life, higher dose-rate 90 Y β-emitting stent more closely mimics the delivery dose rate characteristics of clinically effective β- and γ-wire and balloon brachytherapy devices. We evaluated the dose response characteristics of a 90 Y β-emitting stent in the canine coronary injury model and hypothesized that this device would reduce neointimal formation. Methods: Seventy-seven 90 Y β-emitting coronary stents (15 mm BXTM, 3.0- and 3.5-mm diameter) were implanted in 26 normal dogs (20–25 kg) using a randomized, blinded study design. Stent activity included nonradioactive controls ( n = 24), 4.5 μCi ( n = 15), 8 μCi ( n = 12), 16 μCi ( n = 18), and 32 μCi ( n = 8). Histologic endpoints were assessed at 3 months. Results: Luminal stenosis and neointimal area were similar in control stents and low-activity (4.5 and 8 μCi) 90 Y stents. Higher activity stents (16 and 32 μCi) were associated with significant adverse effects. Frequent total occlusions (5 of 18 stents, 28%; p = 0.008) and a 40% increase in neointimal area ( p = 0.024 vs. control) occurred in the 16 μCi group. Incomplete neointimal healing and a trend for reduced neointimal cell density were evident only in the 16- and 32-μCi group. Conclusion: Despite unique characteristics (2.7 day half-life and a higher dose rate) of 90 Y β-emitting coronary stents, they have an adverse effect on neointimal formation, including frequent total occlusions at high activity levels. Incomplete healing, present 90 days (33 half-lives) after stent placement, indicates prolonged recovery from radiation injury. |
| Databáze: | OpenAIRE |
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