Endovascular brachytherapy using liquid Beta-emitting rhenium-188 for the treatment of long-segment femoropopliteal in-stent stenosis.

PURPOSE: To evaluate the efficacy and safety of endovascular brachytherapy with liquid beta-emitting rhenium-188 (Re-188) in patients with long-segment in-stent stenosis in the femoropopliteal segment. METHODS: From July 2009 to April 2011, 90 consecutive patients (59 men; mean age 68.3±10.3 years, range 43-86) with symptomatic in-stent stenosis/occlusion (24.6-cm mean lesion length) of the femoropopliteal segment underwent angioplasty and subsequent endovascular brachytherapy. The liquid beta-emitting Re-188 was applied to the target lesion within an angioplasty balloon using a dose of 13 Gy at a depth of 2 mm into the vessel wall. Clinical and angiographic follow-up data were collected up to 2 years. The main study endpoints were the 6- and 12-month primary patency rates defined as <50% in-stent stenosis as detected by duplex ultrasound. Clinical endpoints were the cumulative rates of death, amputation, and bypass surgery, as well as improvement in the Rutherford category and the ankle-brachial index. Results were correlated with patient and lesion characteristics. RESULTS: Primary technical success was achieved in all patients, with 1 early stent thrombosis, but no other complications related to the irradiation. Eighty-eight patients reached the 6-month and 82 the 12-month examinations; the primary patency was 95.2% and 79.8%, respectively. In-stent stenosis occurred in 9 patients, while 10 patients had reocclusion of the treated segment. During follow-up, there were 2 late acute thrombotic occlusions, both after discontinuation of clopidogrel. The clinical status improved in 67.0% and 62.2% of the patients after 6 and 12 months, respectively. No patient, lesion, or procedure variables were predictive of restenosis after EVBT. CONCLUSION: EVBT with liquid beta-emitting Re-188 was safe and effective in preventing restenosis in long-segment femoropopliteal ISS.

Endovascular brachytherapy with (192)Ir and (188)Re to treat de novo and recurrent infrainguinal restenoses.

We present a review of the literature on endovascular brachytherapy (EVBT) after percutaneous transluminal angioplasty (PTA) in the femoropopliteal and tibial arteries. The pathophysiological changes induced by PTA and EVBT within the vessel wall, technical considerations regarding 192Ir and 188Re, the results of clinical trials, and the medication required before, during, and after EVBT are summarized.

A Phase II study of external-beam radiotherapy and endovascular brachytherapy with PTA and stenting for femoropopliteal artery restenosis.

PURPOSE: To assess the safety and seek evidence of efficacy of combined external-beam radiotherapy (EBRT) and endovascular brachytherapy in the treatment of stenotic vascular lesions. METHODS AND MATERIALS: Seventeen patients with high risk for restenosis of femoropopliteal arteries were enrolled in this study from February 2000 to August 2002. The external beam radiotherapy regimen consisted of 10 Gy in 5 fractions of 2 Gy, starting on Day 0. This was followed on Day 6 by angiography, stent placement, and intraluminal brachytherapy to a dose of 10 Gy at 1.2 mm from stent surface. The EBRT was continued from the same day to another 10 Gy in 2 Gy daily fractions for 5 days. RESULTS: The follow up ranged from 33 months to 60 months. At the time of analysis 15 of 17 patients were alive with patent stents. Of these, 10 were symptom-free. Two patients died of unrelated causes. CONCLUSIONS: The combination of EBRT and endovascular brachytherapy provided adequate dose distribution without any geographical miss or "candy wrapper" restenosis. No incidence of aneurysmal dilation of radiated vascular segment was observed. The treatment was feasible, well tolerated, and achieved 88% stenosis free survival.

Effects of beta(-)-emitting (188)Re balloon in stented porcine coronary arteries: an angiographic, intravascular ultrasound, and histomorphometric study.

BACKGROUND: Restenosis within stents may be prevented by ionizing radiation from an intravascular source. METHODS AND RESULTS: A liquid beta(-) radiation ((188)Re) balloon was evaluated in a randomized and blinded porcine coronary model of stent restenosis. Group A pigs (n=17) received 0,16, 22, or 29 Gy at 0.5-mm depth, followed by stenting. Restenosis was quantified by angiography, ultrasound, and histomorphometry at 30 days. Group B (n=7) was stented first and then treated with 0 or 29 Gy with follow-up at 60 days. There was a measurable effect at 16 Gy, which improved with increasing doses. At 29 Gy, the histological stenotic area was reduced by 67% (22% versus 66% in controls, P<0.001). Radiation after stenting was equally effective; the stenotic area was reduced (21% versus 65%, P<0.001). At 16 Gy, the vessel just distal to the stent was significantly smaller than control vessels because of intimal thickening (P=0.003). Radiated vessels had distinctive histology consisting of neointimal fibrin and reduced smooth muscle cells and matrix (P<0.0001). CONCLUSIONS: (188)Re balloon brachytherapy in porcine coronary arteries results in dose-dependent and injury-independent inhibition of stent restenosis for up to 60 days. Restenosis at the borders of the irradiated zone is a potential limitation and may be related to underdosing. Brachytherapy with the (188)Re balloon appears to be safe and feasible for clinical studies.

Endovascular brachytherapy for the prevention of restenosis after femoropopliteal angioplasty. Results of the VARA Trial.

AIM: Endovascular brachytherapy (EBT) has been proposed as a method to prevent restenosis. We performed a prospective randomised multicenter study to determine its efficacy for prophylaxis of restenosis after femoropopliteal percutaneous transluminal angioplasty (PTA). METHODS: Patients with symptomatic stenotic or totally occluding lesions in the femoropopliteal artery were randomised to be treated with PTA plus EBT or PTA alone. In case of EBT, 14 Gy was applied by an 192Ir source to the vessel wall. Clinical examination, ankle-brachial pressure index (ABPI) and duplex ultrasound were planned after 6 and 12 months. The primary endpoint was significant restenosis of the treated segment at duplex ultrasound after 12 months. RESULTS: Fifty-three of the 60 patients who eventually met the inclusion criteria could be studied. After 12 months, restenosis rates were 44% (12/27) in the PTA group versus 35% (8/23) in the PTA + EBT group (c2 test, P=0.51). There was no difference in mandatory reintervention between the 2 groups. Overall, EBT resulted in an absolute risk reduction of significant restenosis of 9%, yet in patients with totally occlusive disease this reduction was 32%. CONCLUSIONS: This study suggests an effect of EBT on the occurrence of restenosis only after PTA of occluded femoropopliteal lesions. Due to a too small number of patients analysed this difference is not statistically significant.

Beta radiation and inhibition of recanalization after coil embolization of canine arteries and experimental aneurysms: how should radiation be delivered?

BACKGROUND AND PURPOSE: Beta radiation prevents recanalization after coil embolization. We sought to determine the effects of varying coil caliber, length, activity of 32P per centimeter of coil or per volume, and spatial distribution of coils on recanalization. METHODS: We studied the angiographic evolution of 81 canine maxillary, cervical, and vertebral arteries implanted with a variety of nonradioactive (n=29 arteries) or radioactive (n=52) devices. We compared 1- or 2-caliber 0.015 or 0.010 coils ion-implanted or not with 3 different activity levels (0.05 to 0.08, 0.06 to 0.12, 0.18 to 0.32 microCi/cm) of 32P and totaling 4, 8, and 16 cm in length for the same arterial volume. We also compared inhibition of recanalization by beta radiation delivered by stents, after coil occlusion proximal to or within the stent, with that delivered by coils placed within nonradioactive stents. We finally studied the angiographic evolution of canine lateral wall carotid aneurysms treated with 1 or 2 stents of various activity levels positioned inside the parent artery across the neck. Animals were killed at 4 and 12 weeks for macroscopic photography and pathological examination. RESULTS: All arteries (29 of 29) occluded with nonradioactive devices were recanalized, while 49 of 52 arteries (94%) implanted with 32P devices were occluded at 4 weeks. All aneurysms treated with stents, radioactive or not, demonstrated residual filling of the sac or of channels leading to the aneurysms at follow-up angiography at 4 weeks. CONCLUSIONS: The recanalization process found in the canine arterial occlusion model is minimally affected by coil caliber, number, and length or packing density. Beta radiation reliably inhibits this process, but thrombosis is an essential condition for the efficacy of a radioactive coil strategy.

Endovascular irradiation--a new method to avoid recurrent stenosis after stent implantation in peripheral arteries: technique and preliminary results.

PURPOSE: A high dose rate (HDR) afterloading technique for prevention of vascular stenosis or occlusion after percutaneous transluminal arteriography and subsequent stent implantation caused by intimal hyperplasia is presented. METHODS AND MATERIALS: The frequency of recurrent stenosis or occlusion following implantation of stents into peripheral arteries is relatively high. The cause of relapse is rapid intimal hyperplasia. To prevent proliferation of the intimal layer, intravascular brachytherapy was performed in cases of recurrent vascular occlusion or severe stenosis. After recanalization by percutaneous transluminal angioplasty and stent implantation, a 9-French-ReKa catheter was placed within the lumen of the stent. This catheter served as a guide for a 5-French flexible applicator. Then after individual calculation of the isodose, 12 Gy were applied to the vessel wall. This procedure was followed by 72 h of heparinization. Follow-up by Doppler digital subtraction angiography and magnetic resonance imaging was done 3, 6, and 12 months after the procedure and later on once a year. RESULTS: Intraluminal irradiation was performed in 13 patients (nine male and four female). All patients had a clinically relevant restenosis or reocclusion in the superficial femoral artery (clinical stage according to Fontaine IIb-III). Follow-up time ranged from 3-27 months. After irradiation the stented area remained patent in all cases and there were no signs of recurrent stenosis in the treated arterial segment. CONCLUSION: With high dose rate 192Ir afterloading after percutaneous transluminal angioplasty and subsequent stent implantation restenosis or reocclusion caused by intimal hyperplasia can be prevented.

Simple look-up table of optimized dwell time intervals using a high-dose-rate remote afterloader for endovascular irradiation.

PURPOSE: This article's objective is to develop a simple methodology deliver a uniform radiation dose to the wall of a narrow peripheral artery for preventing restenosis using a high-dose-rate (HDR) 192Ir remote afterloader. METHODS AND MATERIALS: Based upon published two-dimensional data such as anisotropy factors of an HDR 192Ir source calculated from the Monte-Carlo method, arterial wall doses at a close range from an HDR source may be easily calculated using the special formula suggested in Task Group Report No. 43 published by the American Association of Physicists in Medicine. An optimization procedure was used to calculate the optimized dwell times for delivering a uniform dose along arterial walls for various arterial diameters and lengths of lesions. RESULTS: Based on lengths of the stenosis and diameters of arteries or angioplasty balloons, a set of simple look-up tables for optimal dwell time intervals of endovascular radiation treatment have been developed for the MicroSelectron HDR remote afterloader. CONCLUSION: Doses for endovascular irradiation have been accurately calculated with anisotropy factors. For delivering uniform doses along the arterial wall, a set of look-up tables listed for optimal dwell times is available for the HDR remote afterloader.

Feasibility of external beam radiation for prevention of restenosis following balloon angioplasty.

PURPOSE: Brachytherapy has been shown to inhibit neointima formation after vascular balloon injury. This study was done to test the feasibility of low dose external radiation for prevention of restenosis in a non-stented balloon injury model. MATERIALS AND METHODS: Twelve red Duroc swine underwent balloon overdilation injury of both iliac arteries. Twelve Gy was delivered to one side using a Theratron T-1000 Cobalt unit with the other side used as the control. Twelve weeks post injury arteriograms were performed. The animals were then sacrificed and iliac arteries explanted. Histomorphometric analysis of arterial cross sections was performed. RESULTS: Neointima formation was observed in all arteries. Unilateral thrombosis was noted in two animals. The mean neointimal thickness in the radiated and control arteries was 0.63 +/- 0.17 mm and 0.72 +/- 0.31 mm, respectively. The differences in minimal luminal diameter and the neointimal thickness between the two groups were not statistically significant. Complications included superficial hair loss in the radiation port in 4 animals, and 2 deaths prior to the completion date (1 of hemorrhagic enteritis possibly related to the radiation, and 1 of iliac rupture). CONCLUSION: External radiation at this low dose is not effective in preventing vascular restenosis following balloon injury in this animal model.

Intraarterial (192)Ir high-dose-rate brachytherapy for prophylaxis of restenosis after femoropopliteal percutaneous transluminal angioplasty: the prospective randomized Vienna-2-trial radiotherapy parameters and risk factors analysis.

PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

192IR endovascular brachytherapy for avoidance of intimal hyperplasia after percutaneous transluminal angioplasty and stent implantation in peripheral vessels: 6 years of experience.

PURPOSE: Percutaneous transluminal angioplasty (PTA) with or without stent implantation is the accepted standard in the therapy of occlusive arterial disease. Despite improvements in the technique and medical equipment, there is still a restenosis rate of up to 40%. A high-dose-rate afterloading technique to avoid vascular stenosis or occlusion after PTA and subsequent stent implantation caused by intimal hyperplasia is presented with long-term results. METHODS AND MATERIALS: Intravascular brachytherapy with a 10-Ci 192Ir source was performed in cases of recurrent vascular occlusion or stenosis which appeared within 6 months after a previous PTA. After recanalization by PTA and stent implantation, a 9-Fr ReKa catheter was positioned within the stent to center the applicator with its tip 2 cm below the stent. This catheter served as a guide for a 5-Fr flexible applicator. After this procedure the isodose was calculated and a 12-Gy to 3-mm source distance was applied. The procedure was followed by 72 h of heparinization. RESULTS: From May 1990 to June 1996, 28 patients (21 male and seven female) were treated with endovascular brachytherapy. All patients had a clinically relevant restenosis or reocclusion of the arteria femoralis. Follow-up time ranged from 1 to 71 months. Twenty-eight patients had a sufficient follow-up time; 25 of these patients were examined. Twenty-one patients had treated vessel segments; four patients had no flow in the treated area. Two patients moved away with unknown addresses, and one patient died without any follow-up examination. Radiation-associated side effects were not notable. CONCLUSION: Intraluminal brachytherapy with 192Ir is a safe and useful procedure to avoid endovascular hyperplasia after transluminal percutaneous angioplasty.

[Endovascular brachytherapy to prevent restenosis after angioplasty]. / Endovaskuläre Brachytherapie in der Restenoseprophylaxe nach Angioplastie und Stentimplantation: Eine Ubersicht.

Endovascular radiotherapy is the first effective prophylaxis of restenosis after percutaneous transluminal angioplasty (PTA) and stenting. The FDA recently approved two devices for the delivery of intracoronary radiation following coronary artery stenting. Published multicenter, double-blind, randomized trials of intracoronary radiation therapy report good results for preventing in-stent restenosis, while the data for the peripheral circulation are still inconclusive. Beta-emitters are easier applicable and probably also safer, whereas gamma-emitters have been more extensively evaluated clinically so far. Primary indication for endovascular brachytherapy are patients at high risk for restenosis, such as previous restenoses, in-stent hyperplasia, long stented segment, long PTA lesion, narrow residual vascular lumen and diabetes. Data from coronary circulation suggest a safety margin of at least 4 to 10 mm at both ends of the angioplastic segment to avoid edge restenosis. To prevent late thrombosis of the treated coronary segment, antiplatelet therapy with clopidogrel and aspirin are recommended for at least 6 months after PTA and for 12 months after a newly implanted stent. An established medication regimen after radiotherapy of peripheral arteries is still lacking.

The role of radiation therapy in the treatment of femoropopliteal occlusive disease.

With the success of brachytherapy in the coronary vessels as a guide, it has also shown promising initial results as an adjunct for the treatment and prevention of restenosis of femoropopliteal occlusive disease. With the rapid evolution of endovascular therapy, defining the role of brachytherapy will become even more important. The purpose of this review is to provide an overview of the role of brachytherapy in the treatment of restenosis following femoropopliteal endovascular intervention.

Vascular brachytherapy: update on clinical trials.

The ultimate test for any emerging technology to become a standard of care depends on the outcome of the clinical trials. In the field of vascular brachytherapy, we are currently in the midst of multi-center, randomized clinical trials, and at the same time, data is being collected regarding long-term outcome of patients that enrolled early on in the pilot trials. These reports have recently reached three years of clinical and angiographic information on patients who were treated with intracoronary radiation for the prevention of restenosis. These data may give a clue to potential side effects and to the ultimate question: will dose radiation therapy be a standard of care for prevention of restenosis?

Pulsed magnetotherapy in Czechoslovakia--a review.

Pulsed magnetotherapy has been used in Czechoslovakia for more than one decade. It has been proved that this type of physical therapy is very efficient mainly in rheumatic diseases, in paediatrics (sinusitis, enuresis), and in balneological care of patients suffering from ischaemic disorders of lower extremities. Promising results have also been obtained in neurological diseases (multiple sclerosis, spastic conditions) and in ophthalmology, in degenerative diseases of the retina.

Peripheral vascular brachytherapy: an introduction.

The response of cells to ionising radiation has been extensively studied for the past 30 years. When radiation is absorbed in biological material, it can directly ionise a critical site (direct effect) or interact with other molecules to produce reactive free radicals, which can subsequently damage critical biological molecules (indirect effect). DNA is considered the critical target damaged by ionising radiation by both direct and indirect processes. Since radiotherapy had proven to be effective in the treatment of non-malignant proliferative processes, it was assumed that this adjunctive treatment would also inhibit vascular restenosis. The major difference between external and intravascular radiation is dose distribution. Intravascular delivery results in extremely high doses to the lumen with a fall-off in dose as a function of distance from the source; whereas, external beam would deliver a uniform dose over the entire volume of tissue treated. Unlike in the coronary circulation most of the peripheral vessels treated are greater than 3 mm in diameter; in fact many are 7 to 10 mm in diameter. Since beta radiation is related to lower penetration properties and more heterogeneous distribution of radiation in comparison to gamma radiation, it is therefore necessary to use a gamma radiation source because it would be difficult to irradiate the sub-intimal tissue with a beta source centred in a large vessel. Radiation can and does have the potential to destroy blood vessels. The challenge in vascular brachytherapy is to treat blood vessels to a point where restenosis is inhibited; yet the vessel is not irreparably damaged.

Assessment of cerebral hemodynamics before and after revascularization in patients with occlusive cerebrovascular disease by means of quantitative IMP-SPECT with double-injection protocol.

UNLABELLED: The purpose of this study was to validate a double-injection (DI) method with N-isopropyl-[123I]p-iodoamphetamine (IMP) to measure regional cerebral blood flow (rCBF) twice in a single session of dynamic SPECT and to elucidate a possible role of this method to identify patients with occlusive disease of major cerebral arteries, who might benefit from cerebral revascularization procedures (CR). MATERIALS AND METHODS: Fourteen patients with occlusion or severe stenosis of the internal carotid or middle cerebral artery were studied before and after CR to assess hemodynamic changes after revascularization treatment. We quantitatively measured rCBF before and after acetazolamide (ACZ) challenge along with cerebrovascular reserve capacity (CVR) with two injections of IMP in a single session of dynamic SPECT scans (DI method). The reliability and reproducibility of the DI method were validated by means of a simulation study and in eight patients who were examined without ACZ challenge to measure baseline rCBF twice. RESULTS: The analysis of simulated noisy data with realistic noise levels showed that the errors of the estimates for the first and the second rCBF and for the increase in rCBF were 2.6%, 8.1% and 10.4%, respectively. In the 8 patients examined by the DI method to measure baseline rCBF twice, the mean and the SD of percentage differences between the two consecutive measurements in rCBF were -1.3% and 5.5%, respectively. Eight out of 14 patients with occlusive disease had at least one region with a CVR less than 10%. They showed a significant increase in resting rCBF after CR, not only in the ipsilateral hemisphere (from 26.1 +/- 6.4 to 33.4 +/- 4.7) but also in the contralateral one (from 28.3 +/- 7.0 to 34.7 +/- 4.7) with a recovery of the ipsilateral CVR from 9.3 +/- 17.2 to 41.2 +/- 20.1%. The remaining six patients with good-moderate CVR did not show an increase in rCBF after CR (from 28.0 +/- 2.7 to 28.3 +/- 3.4). The three of them with a moderate CVR (10-25%) before CR showed normalization of CVR after CR. CONCLUSION: Patients with decreased rCBF and reduced CVR benefited from CR in terms of an increase in rCBF and recovery of CVR. The quantitative double-injection IMP-SPECT has the ability to identify those patients who may benefit from CR.

High dose rate endovascular brachytherapy in aorto-iliac lesion for the prevention of restenosis.

This study examined the applicability of endovascular brachytherapy to larger del arteries such as the abdominal aorta and iliac artery. Endovascular brachytherapy using an Ir-192 HDR source was administered 11 times to nine patients who had undergone percutaneous transluminal angioplasty (PTA) between 1995 and 1999. The follow-up lasted 13 to 55 months after treatment (median, 24 months). Eight of the 11 lesions have been controlled so far. Although one case developed thrombus inside the stent five months later, recanalization was achieved by means of retreatment. One patient who underwent low-dose irradiation (6 Gy) without stent implantation showed restenosis five months after treatment. We used a centering catheter that did not block the blood stream for exact centering of the radiation source in larger vessels such as the abdominal aorta. Although endovascular brachytherapy is a promising and safe procedure, careful follow-up is needed to detect untoward reactions such as thrombosis.

Endovascular brachytherapy in peripheral arteries.

Increasing knowledge about the pathophysiology of the process leading to restenosis has given the rationale to investigate the potential role of radiation in the prevention of restenosis. Compared to the rapidly increasing experience in the coronary circulation, there is until now only a limited number of studies concerning the use of brachytherapy (BT) in the peripheral circulation. The-Vienna 2-Trial was the first randomized study to demonstrate the efficacy of endovascular BT for prophylaxis of restenosis after femoropopliteal percutaneous transluminal angioplasty. The cumulative patency rates at 12 months of follow-up were 63.6% in the PTA + BT-group and 35.3% in the PTA-group (p < 0.005), and the significant improvement in patency was also maintained after two years. The results of two ongoing randomized, double-blinded multicenter trials (PARIS; Vienna 3) have to be awaited before definitive recommendations can be given. The rather high incidence of late thrombotic occlusion after long-segment femoropopliteal stenting and endovascular BT requires optimization of the antithrombotic regimen.

[Use of radiotherapy in cardiovascular disease. Radiophysical basis, current results, indications and perspectives]. / La curiethérapie en pathologie cardiovasculaire. Bases radiophysiques, résultats actuels, indications et perspectives.

Restenosis is the main limitation of percutaneous angioplasty, especially in vessels of small diameters such as the coronary arteries, the femoro-popliteal and tibial-peroneal arteries and the arterio-venous dialysis grafts. The extensive use of tents has not entirely prevented its occurrence, whereas treating in-stent restenosis gives even more uncertain results. Endovascular radiotherapy has emerged over the past few years as a promising approach to both prevent and cure it. The analogy between the tumour-like cellular proliferations observed in post-angioplasty restenosis and tumour processes prompted pioneering works to study the effect of ionizing radiations in animal models of arterial restenosis. The demonstrated feasibility, tolerance and efficacy of this approach lead to test this strategy in humans. The results of 3 recently presented randomized double-blind trials in the treatment of coronary in-stent restenosis have been so promising that endovascular brachytherapy might now be considered the treatment of choice in this indication. Other randomized trials are currently carried out to test whether endovascular brachytherapy may prevent restenosis in coronary and femoro-popliteal arteries as well as in hemodialysis shunts. In the present review, we describe the basics of the biological effects of ionizing radiations, the technical modalities to deliver endovascular radiations, our current knowledge about their effects on the vascular wall and the restenosis mechanisms, and the results of the first clinical studies. Finally, we address the remaining problems in the use of endovascular curietherapy and question the promises and challenges of its clinical application.