Main Session
Sep
28
PQA 04 - Breast Cancer, Patient Reported Outcomes/QoL/Survivorship, Functional Radiation Medicine, Hematologic Malignancies, Palliative Care, and International/Global Oncology
Presenter(s)
Joseph DeCunha, PhD - University of Washington/Fred Hutch Cancer Center, Seattle, WA
K. Wallner1, K. E. Kearney2, J. M. DeCunha3, E. Y. Kim1, L. Azzalini2, M. R. Folkert1, G. A. Sandison1, W. L. Lombardi2, S. Kumar2, B. Sengupta4, C. Don2, and M. Kim1; 1Department of Radiation Oncology, University of Washington, Seattle, WA, 2Division of Cardiology, Department of Medicine, University of Washington, Seattle, WA, 3Department of Radiation Oncology, University of Washington/Fred Hutchinson Cancer Center, Seattle, WA, 4Department of Radiation Oncology, University of Washington and Fred Hutchinson Cancer Center, Seattle, WA
Purpose/Objective(s):
Of the more than half million percutaneous coronary interventions (PCIs) performed in the United States annually, on the order of 10% of those are performed to treat in-stent restenosis (ISR). For patients treated with an initial drug eluting stent (DES), treatment for ISR generally involves repeated stenting with an additional DES. If an intervention existed to prolong the restenosis-free interval following treatment for DES-ISR, tens of thousands of patients in the United States stand to benefit annually. Intravascular brachytherapy (IVBT) has well-proven activity against coronary restenosis of a native vessel or a single bare metal stent. However, its effectiveness for multiply recurrent same vessel ISR is unproven. When randomized control trials are impractical there has been interest in using within-patient controls referred to as “N-of-1”, or “single-case experimental design” trials. The objective of this work is to determine if IVBT prolongs the ISR-free interval in patients with recalcitrant ISR by comparison to each patient’s own ISR-free interval prior to and following IVBT.Materials/Methods:
Patients were accrued from a tertiary interventional cardiac center. Patients with an ISR-free interval of less than 2 years prior to IVBT were enrolled on an IRB-approved prospective registry. Standard IVBT techniques were used, with doses of 18, 23 or 34 Gy prescribed at 2 mm from the 90Sr radiation source with higher doses prescribed for larger diameter vessels. 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. Twenty-six vessels in 19 patients were studied.Results:
ISR-free intervals prior to IVBT ranged from 25 to 317 days (median= 96 days) compared to ISR-free intervals after IVBT that ranged from 30 to 612 days (median=350 days, p<0.001, log-rank test).Conclusion:
The results support the use of IVBT to prolong the ISR-free interval in recalcitrant ISRs.