Intravascular Radiation Delays Recurrence of Recalcitrant Coronary In-Stent Restenosis.

PURPOSE: Intravascular brachytherapy (IVBT) has a well-proven activity against coronary restenosis of a native vessel or a single bare metal stent. However, its effectiveness for multiple recurrent same-vessel in-stent restenoses (ISRs) is unproven. The objective of this study was to determine if IVBT prolongs the ISR-free interval in recalcitrant lesions. METHODS AND MATERIALS: ISR-free intervals before and after IVBT for individual patients were compared. T1 was the ISR-free interval prior to IVBT, and T2 was the ISR-free interval after IVBT. Accrual was sought from patients with a prior ISR-free interval of less than 2 years. Standard radiation techniques were used, with doses of 18, 23, or 34 Gy prescribed at 2 mm from the radiation source. ISR-free intervals before (T1) and after IVBT (T2) were compared. RESULTS: Twenty-six vessels in 19 patients were studied. ISR-free intervals prior to IVBT ranged from 25 to 317 days (median, 96 days) compared with ISR-free intervals after IVBT that ranged from 30 to 612 days (median, 350 days; P < .001; log-rank test). CONCLUSION: The results support the use of IVBT to prolong the ISR-free interval in recalcitrant ISRs.