Pokrajac B, Pötter R, Maca T, Fellner C, Mittlböck M, Ahmadi R, Seitz W, Minar E
Department of Radiotherapy and Radiobiology, University of Vienna, General Hospital of Vienna, Vienna, Austria.
Int J Radiat Oncol Biol Phys. 2000 Nov 1;48(4):923-31. doi: 10.1016/s0360-3016(00)00716-1.
The aim of the Vienna-2-trial was to compare the restenosis rate of femoropopliteal arteries after percutaneous transluminal angioplasty (PTA) with or without intraarterial high-dose-rate (HDR) brachytherapy (BT) using an (192)Ir source.
A prospective, randomized trial was conducted from 11/96 to 8/98. A total of 113 patients (63 men, 50 women), with a mean age of 71 years (range, 43-89 years) were included. Inclusion criteria were (1) claudication or critical limb ischemia, (2) de-novo stenosis of 5 cm or more, (3) restenosis after former PTA of any length, and (4) no stent implantation. Patients were randomized after successful PTA for BT vs. no further treatment. A well-balanced patient distribution was achieved for the criteria used for stratification, as there were "de-novo stenosis vs. restenosis after former PTA," "stenosis vs. occlusion," "claudication vs. critical limb ischemia" and above these for "diabetes vs. nondiabetes." PTA length was not well balanced between the treatment arms: a PTA length of 4-10 cm was seen in 19 patients in the PTA alone group and in 11 patients in the PTA+BT group, whereas a PTA length of greater than 10 cm was seen in 35 patients and 42 patients, respectively. A dose of 12 Gy was prescribed in 3-mm distance from the source axis. According to AAPM recommendations, the dose was 6.8 Gy in 5-mm distance (vessel radius + 2 mm). Primary endpoint of the study was femoropopliteal patency after 6 months.
PTA and additional BT were feasible and well tolerated by all 57 pts in this treatment arm. No acute, subacute, and late adverse side effects related to BT were seen after a mean follow up of 12 months (6-24 months) in 107 patients (PTA n = 54; PTA+ BT n = 53). Crude restenosis rate at 6 months was in the PTA arm 54% vs. 28% in the PTA + BT arm (chi(2) test; p < 0.013). Actuarial estimate of the patency rate was at 6 months 45% vs. 72% (p < 0.004). Comparison of restenosis rates for the different subgroups with risk factors (restenosis after former PTA, occlusion and PTA length >10 cm) showed significant decrease of the restenosis rate, if BT was added. Significant reduction was not achieved in diabetes patients.
BT after femoropopliteal PTA is feasible and a safe therapeutic option. No BT related morbidity was observed. A significant reduction of the restenosis rate was obtained in the PTA+BT arm. Subgroup analysis showed significant decrease of restenosis rate in the subgroups with restenosis after former PTA, occlusion and PTA length of greater than 10 cm. With dose escalation and reduction of dose variation by a centering device a further significant decrease of restenosis rate can be expected.
维也纳-2试验的目的是比较经皮腔内血管成形术（PTA）后，股腘动脉再狭窄率在使用或不使用（192）铱源进行动脉内高剂量率（HDR）近距离放射治疗（BT）情况下的差异。
于1996年11月至1998年8月进行了一项前瞻性随机试验。共纳入113例患者（63例男性，50例女性），平均年龄71岁（范围43 - 89岁）。纳入标准为：（1）间歇性跛行或严重肢体缺血；（2）新发狭窄5厘米或更长；（3）既往任何长度的PTA术后再狭窄；（4）未植入支架。患者在PTA成功后随机分为接受BT组和不再接受进一步治疗组。对于用于分层的标准，实现了患者分布的良好平衡，分层标准包括“新发狭窄与既往PTA术后再狭窄”、“狭窄与闭塞”、“间歇性跛行与严重肢体缺血”，以及在此之上的“糖尿病与非糖尿病”。治疗组间PTA长度分布不均衡：单纯PTA组19例患者的PTA长度为4 - 10厘米，PTA + BT组11例患者的PTA长度为4 - 10厘米，而PTA长度大于10厘米的患者在单纯PTA组为35例，在PTA + BT组为42例。在距源轴3毫米处规定剂量为12 Gy。根据美国医学物理学家协会（AAPM）的建议，在5毫米距离（血管半径 + 2毫米）处剂量为6.8 Gy。该研究的主要终点是6个月后股腘动脉通畅情况。
在该治疗组的所有57例患者中，PTA及附加BT操作可行且耐受性良好。在107例患者（PTA组n = 54；PTA + BT组n = 53）平均随访12个月（6 - 24个月）后，未观察到与BT相关的急性、亚急性和晚期不良副作用。6个月时，单纯PTA组的粗再狭窄率为54%，而PTA + BT组为28%（卡方检验；p < 0.013）。6个月时通畅率的精算估计分别为45%和72%（p < 0.004）。对具有危险因素（既往PTA术后再狭窄、闭塞和PTA长度 > 10厘米）的不同亚组的再狭窄率进行比较，结果显示添加BT后再狭窄率显著降低。糖尿病患者未实现显著降低。
股腘动脉PTA后进行BT是可行且安全的治疗选择。未观察到与BT相关的发病率。PTA + BT组的再狭窄率显著降低。亚组分析显示，在既往PTA术后再狭窄、闭塞和PTA长度大于10厘米的亚组中，再狭窄率显著降低。随着剂量增加以及通过中心装置减少剂量变化，预计再狭窄率可进一步显著降低。
