Vascular brachytherapy (VBT) is the only proven treatment option for patients with in-stent restenosis. In seven randomised trials with almost 1500 patients that evaluated γ (five studies) and β (two trials) irradiation, target vessel failure reduction ranged from 73% to 34% by VBT compared with conventional angioplasty.¹ However, the reported restenosis rates with the active treatment still varied between 17% and 32%.¹ We therefore postulated that repeat VBT is safe and efficacious for preventing refractory in-stent restenosis in high risk patients with failed VBT.

METHODS

Beginning in January 1999, VBT was applied for all patients with in-stent restenosis. VBT was systematically performed with intravascular ultrasound (IVUS) guidance. The repeat procedure was performed with a strontium/yttrium-90 source train (BetaCath, Novoste, Norcross, Georgia, USA). The design and application of this catheter have been described previously.² The dosimetry was based on the manufacturer’s recommendations but taking into account not the angiographic vessel reference diameter but the external elastic membrane diameter (as determined by IVUS). The mean dose delivered at 2 mm from the source centre was 23.3 (2.2) Gy during the index procedure and 25.3 (2.2) Gy during the repeat intervention. Percutaneous coronary intervention (PCI) was performed according to standard clinical practice.

Failed VBT was defined as angina recurrence combined with target vessel failure (as documented by any repeat angiography: premature depending on early symptom recurrence or at the planned six month control). Repeat VBT was considered for patients estimated to be at high risk for refractory in-stent restenosis or if they had a prognostic risk—that is, diffuse or ostial in-stent restenosis or total …