Radiolabeling brachytherapy sources with Re-188 through chelating microfilms: stents

Area of Science:

• Nuclear Medicine
• Materials Science
• Oncology

Background:

• Rhenium-188 (Re-188) is a radionuclide with suitable beta emission properties for brachytherapy.
• Developing efficient methods for attaching Re-188 to medical devices is crucial for targeted radiation delivery.

Purpose of the Study:

• To develop and characterize a method for on-demand radiolabeling of brachytherapy sources, specifically metal stents, with Rhenium-188.
• To evaluate the in vitro and in vivo performance of Re-188 labeled stents for intravascular brachytherapy.

Main Methods:

• Plasma deposition of a siloxane film with reactive amines onto metal surfaces.
• Conjugation of a chelating microfilm to the amine-functionalized surface.
• Radiolabeling with Rhenium-188 (Re-188) and characterization of binding capacity and yield.
• In vitro phantom studies and in vivo scintigraphy in porcine arteries.

Main Results:

• Successful attachment of Re-188 to metal wafers and stents via a chelating microfilm.
• Wafers bound up to 62.9 MBq, and stents bound up to 26.6 MBq of Re-188.
• Stents delivered therapeutic doses (10-30 Gy at 2 mm) in arterial wall models.
• In vivo studies confirmed stent localization and minimal systemic activity.

Conclusions:

• On-demand radiolabeling of stents and other brachytherapy sources with Re-188 is feasible and can be performed routinely.
• The developed method allows for targeted delivery of radiation, minimizing off-target effects.
• Re-188 labeled stents show potential for effective intravascular brachytherapy.