A comparison of intravascular source designs based on the beta particle emitter {sup 114m}In/{sup 114}In Line source versus stepping source
Background: Catheter-based intravascular brachytherapy (IVB) sources of the next generation will have to meet high demands in terms of miniaturization, flexibility, safety, reliability, costs and versatility. The radionuclide pair {sup 114m}In/{sup 114}In (half-life 49.51 days, maximum beta energy 2.0 MeV, average beta energy 0.78 MeV) is an attractive beta emitter for application in such a source. Methods: Since metallic indium is unfit for the manufacture of a brachytherapy source, the feasibility, safety and dosimetric properties of a design concept comprising a linear array of ceramic In{sub 2}O{sub 3} spheres within a thin-walled, superelastic Ni/Ti capsule are investigated. Results: Neutron activation of enriched In{sub 2}O{sub 3} spheres yields a specific activity sufficiently high for the manufacture of a stepping source, keeping treatment times limited to a few minutes. Although {sup 114m}In/{sup 114}In also emits some gamma radiation, the effective doses received by members of the medical staff are an order of magnitude lower than those received from fluoroscopy. The dose distributions about a 40-mm line source and a 5-mm stepping source (outer diameter 0.36 mm) are calculated using MCNP4C. Dose-volume histograms (DVHs) are calculated for the line source (centered and noncentered) and the stepping source (centered) using the geometry of a human coronary artery. Conclusion: The results show that a centered stepping source with optimized dwell times delivers the most homogenous dose within the target volume.
- OSTI ID:
- 20650539
- Journal Information:
- Cardiovascular Radiation Medicine, Vol. 3, Issue 1; Other Information: PII: S1522186502001476; Copyright (c) 2002 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 1522-1865
- Country of Publication:
- United States
- Language:
- English
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