1 research outputs found
Inhibition of restenosis with beta-emitting radiotherapy: Report of the Proliferation Reduction with Vascular Energy Trial (PREVENT)
BACKGROUND: Intracoronary gamma- and beta-radiation have reduced
restenosis in animal models. In the clinical setting, the effectiveness of
beta-emitters has not been studied in a broad spectrum of patients,
particularly those receiving stents. METHODS AND RESULTS: A prospective,
randomized, sham-controlled study of intracoronary radiotherapy with the
beta-emitting (32)P source wire, using a centering catheter and automated
source delivery unit, was conducted. A total of 105 patients with de novo
(70%) or restenotic (30%) lesions who were treated by stenting (61%) or
balloon angioplasty (39%) received 0 (control), 16, 20, or 24 Gy to a
depth of 1 mm in the artery wall. Angiography at 6 months showed a target
site late loss index of 11+/-36% in radiotherapy patients versus 55+/-30%
in controls (P:<0.0001). A low late loss index was seen in stented and
balloon-treated patients and was similar across the 16, 20, and 24 Gy
radiotherapy groups. Restenosis (>/=50%) rates were significantly lower in
radiotherapy patients at the target site (8% versus 39%; P:=0.012) and at
target site plus adjacent segments (22% versus 50%; P:=0.018). Target
lesion revascularization was needed in 5 radiotherapy patients (6%) and 6
controls (24%; P:<0.05). Stenosis adjacent to the target site and late
thrombotic events reduced the overall clinical benefit of radiotherapy.
CONCLUSIONS: beta-radiotherapy with a centered (32)P source is safe and
highly effective in inhibiting restenosis at the target site after stent
or balloon angioplasty. However, minimizing edge narrowing and late
thrombotic events must be accomplished to maximize the clinical benefit of
this modality