Complications of intravascular brachytherapy.

Introduction: There is some evidence of a dose-response relationship for intravascular brachytherapy (IVBT) of native vessel or first-time in-stent restenosis (ISR). It has also been shown that in-field failure predominates following intravascular brachytherapy-treated lesions. Accordingly, it may be advantageous to increase the radiation dose(s) currently used. Given the rationale for escalation from currently doses, a scrutiny of the potential complications that have been reported seems timely.

Methods: PubMed was searched from 1966 through November 21st, 2023, using the terms coronary and brachytherapy, yielding 1287 references. A 10/16/24 follow-up search of Embase, using the terms "coronary and brachytherapy and complications", yielding 511 articles. In total, 68 articles were identified as adverse event reports based on their title, or by scrutinizing articles that did not mention adverse events in their titles.

Results: The best documented adverse IVBT-related event is the occurrence of late (> 1 month) thrombosis. Following identification of the risk, longer DAPT regimens were adopted, bringing the incidence to non-IVBT levels. A variety of other adverse events have been reported, including aneurysms, dissections, arterial spasm, "black holes" and vasomotor response inhibition. However, none of which were associated with adverse clinical outcomes.

Conclusions: Nearly all reports regarding IVBT-related complications are retrospective analyses of a limited number of events, subject to reporting bias. Clinically important IVBT-related complications, at current doses, appear highly unlikely.