Prevention of restenosis by external beam ionizing irradiation

Intravascular brachytherapy with gamma sources has been proved to prevent i n-stent restenosis in recent clinical trials. Beta sources are also being i nvestigated. The intravascular use of radioactive sources has raised theore tical and logistic problems and renewed the interest in teletherapy for the treatment and prevention of restenosis. We review the literature published on the use of teletherapy in animal models and compare it to brachytherapy from biological and logistic points of view. Developing technologies for s tereotactic radiotreatment of moving targets may offer new solutions and ar e being studied.