Safety and efficacy of manual stepping and overlapping of beta-emitter for diffuse in-stent restenosis lesions.
BACKGROUND
The effects of overlapping beta-emitter sources on the treatment of in-stent restenosis (ISR) lesions as a result of manual stepping are unknown.


RESULTS
In the BETA WRIST (Beta Washington Radiation for In-stent Restenosis Trial), 17 out of the 50 patients who received radiation treatment had diffuse ISR in native coronaries that required manual stepping of the beta-emitter (90Y) source in order to cover the lesion and the edges. Fourteen of those patients received radiation with an overlap of up to 3 mm in the middle of the stented segment. The prescribed dose was 20.6 Gy to a distance of 1.0 mm from the surface of the inflated balloon, and the calculated dose to the vessel wall at the overlapped area did not exceed 75 Gy. There was no difference in late total occlusion (7.1% vs. 9.0%, P=NS) and target lesion revascularization (28.5% vs. 27.2%, P=NS) between patients with stepping and those without stepping. At 6 months, there was no evidence of perforation or aneurysm at the overlapped segments. Quantitative coronary angiographic (QCA) analysis revealed significantly reduced late loss in the overlapped segment compared to the adjacent segment (P=.04). Serial (postradiation vs. follow-up) IVUS measurement showed larger mean lumen cross-sectional area (CSA) (P=.0035) and smaller mean intimal hyperplasia (IH) CSA (P=.0010) in the overlapped segment compared to the adjacent segment.


CONCLUSIONS
Manual stepping of beta-emitter source with a short overlapped segment is safe for diffuse ISR. Further increase in lumen dimension and reduction in IH formation are observed at the overlapped segment.
Kim
Han-Soo
HS
Cardiovascular Research Institute, Washington Hospital Center, 110 Irving St., NW, Suite 4B-1, Washington, DC 20010, USA.
Waksman
Ron
R
Chan
Rosanna C
RC
Pappas
Chrysoula K
CK
Bhargava
Balram
B
Ajani
Andrew E
AE
Bui
Anh B
AB
Yazdi
Hamid A
HA
Mintz
Gary S
GS
Satler
Lowell F
LF
Kent
Kenneth M
KM
Pichard
Augusto D
AD
D000328:Adult; D000368:Aged; D001610:Beta Particles / Q000627:therapeutic use*; D019917:Blood Vessel Prosthesis Implantation; D002404:Catheterization; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000628:therapy; D023903:Coronary Restenosis / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008370:Manuals as Topic; D008875:Middle Aged; D015607:Stents; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional; D015021:Yttrium Radioisotopes / Q000627:therapeutic use*
D015021:Yttrium Radioisotopes