Ytterbium-169: A promising new radionuclide for intravascular brachytherapy
Purpose: To explore the feasibility of 169Yb (γ, 93 keV) as a new radionuclide for intravascular brachytherapy (IVBT) in terms of dose distribution, penetration power, and radiation safety features as compared with 125I and 192Ir. Methods: The dose distributions for catheter-based sources, 169Yb, 12...
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Published in | Cardiovascular radiation medicine Vol. 2; no. 3; pp. 173 - 180 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
Elsevier Inc
01.07.2001
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Subjects | |
Online Access | Get full text |
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Summary: | Purpose: To explore the feasibility of
169Yb (γ, 93 keV) as a new radionuclide for intravascular brachytherapy (IVBT) in terms of dose distribution, penetration power, and radiation safety features as compared with
125I and
192Ir.
Methods: The dose distributions for catheter-based sources,
169Yb,
125I, and
192Ir, in homogeneous water and in the presence of calcium and a steel stent have been determined and compared using the Monte Carlo method (MCNP4B2 code). The dose rates of the sources were evaluated from 0.02 to 100 cm.
Results: In the short distance range (0.02<
r<1.0 cm), the dose distributions in homogeneous water are very similar for the three radionuclides when the dose rates are normalized at 2 mm. Between 1 and 20 cm, the relative dose rates fall off similarly for
169Yb and
192Ir, whereas for
125I, it decreases much more rapidly. At a distance further away (
r∼100 cm), the dose rate of
169Yb is about 10 times lower than that of
192Ir, indicating the cathlab radiation shielding requirement for
169Yb is substantially reduced as compared with
192Ir. Calcified plaques and stents cause a drastic dose reduction in the arterial wall for
125I, but have no effect for
192Ir γ-rays. Only slight dose reductions were detected for
169Yb beyond a layer of 1.0-mm calcium (2–3%), and behind a steel stent strut (5%).
Conclusion:
169Yb is a promising new radionuclide for IVBT. It has a much better penetrating power through calcified plaques and stents compared with the low-energy source
125I. It also provides easier radiation protection measures for cardiac cathlab personnel than the high-energy source
192Ir, while preserving a favorable dose distribution in tissues surrounding an arterial vessel. |
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ISSN: | 1522-1865 |
DOI: | 10.1016/S1522-1865(01)00085-3 |