Dosimetry of a 188rhenium-labeled self-expanding stent for endovascular brachytherapy in peripheral arteries.

Abstract

PURPOSE:

Radioactive stents have been proposed as endovascular irradiation device to prevent in-stent restenosis by inhibiting neointimal proliferation. 32P-stents have been used in several studies so far, but require large-scale labeling procedures and endovascular barotrauma for stent expansion supporting the development of edge restenosis. Purpose of this study was to establish dosimetry of a self-expanding nitinol stent for peripheral vascular disease, which was radiolabeled with 188rhenium (188Re) by a dip coating technique.

METHODS AND MATERIALS:

The surface of nitinol Memotherm FLEXX stents was polymer-coated providing functional NH(2) groups for diethylenetriaminepentaacetic acid (DTPA) binding, providing the ligand for the complexation of 188Re onto the stent surface. Stability of radiolabeling was tested over 48 h using an in vitro blood circulation (Chandler Loop). Radial and longitudinal dose distributions of a radiolabeled stent were obtained with a plastic scintillator dosimetry system.

RESULTS:

Stents with a length of 30 mm and a diameter of 8 mm were labeled with up to 33 MBq 188Re. A total of 69+/-4% of the labeled 188Re remained stable on the stent surface after 48 h. Ninety-five percent of the infinitely accumulated dose was supplied to the target tissue within 72 h. Including correction for radioactivity washout from the stent, the infinitely accumulated dose at 1 mm radial distance from the stent surface was 1.85+/-0.19 Gy/MBq 188Re/cm stent length.

CONCLUSIONS:

We developed a technique for radiolabeling of self-expanding nitinol stents with 188Re by dip coating and formation of 188Re chelate complexes. We provide dosimetry data useful for application of this beta-emitting stent for endovascular brachytherapy in peripheral vascular occlusive disease.

• Authors: B Nowak, J M Meyer, T Goergen, D Fluehs, S Block, R W Guenther, H Hoecker, U Buell
• Journal: Cardiovascular radiation medicine (Cardiovasc Radiat Med) 2001 Oct-Dec Vol. 2 Issue 4 Pg. 246-53 ISSN: 1522-1865 [Print] United States
• PMID: 12160767 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Radioisotopes
• Rhenium

Topics

• Brachytherapy (instrumentation, methods)
• Humans
• Peripheral Vascular Diseases (radiotherapy)
• Radioisotopes
• Radiometry
• Rhenium (therapeutic use)
• Stents