Safety and mechanisms of intracoronary manual stepping brachytherapy as gained from serial angiographic and intravascular ultrasound studies

In-stent restenosis remains the Achilles’ heel of coronary stent implantation, especially in long lesions. Stent length has been identifi ed as an independent predictor of restenosis. 1 Restenosis rates after stenting of long lesions can reach up to 50%. 2 The predominant mechanism is neointima formation. 3 Recently, endovascular irradiation using emitters for in-stent restenosis has demonstrated signifi cantly reduced restenosis rates. 4,5 Due to the limited length of the radioactive source, longer lesions require manual stepping brachytherapy (MSB) for adequate coverage of the entire injured (i.e., having been treated with an angioplasty device) vessel segment, thus exhibiting the risk of geographic miss or overdosage due to insuffi cient or extensive overlap, respectively. We report on the effects of MSB on vessel geometry as assessed by serial intravascular ultrasound. Following transcatheter intervention with the cut