Intravascular ultrasound analysis of beta radiation therapy for diffuse in-stent restenosis to inhibit intimal hyperplasia

We evaluated the efficacy of β-radiation therapy (¹⁸⁸Re-MAG₃) to inhibit intimal hyperplasia (IH) in diffuse in-stent restenosis by intravascular ultrasound (IVUS) analysis in 50 patients. Nine patients who did not agree with radiation therapy, and therefore underwent rotational atherectomy and balloon angioplasty for diffuse in-stent restenosis in the same study period, were selected for control groups. Serial IVUS comparisons were available in 44 of 50 patients with radiation therapy and 7 of 9 control patients. At 6-month follow-up, there was less significant increase of IH area in patients with radiation therapy than in control patients (Δ IH area = 0.1±0.8 mm² vs. 2.6±1.8 mm², P>0.001 in mean values, and 0.6±1.4 mm² vs. 2.9±2.1 mm², P = 0.026 in values of follow-up lesion site, respectively). In conclusion, β-radiation therapy might be an effective treatment modality to inhibit intimal hyperplasia in patients with diffuse in-stent restenosis.