33 Endovascular Brachytherapy

Endovascular Brachytherapy 659

trials. Results reported so far refer to more than 2000 patients and mainly focus on the overall therapeutic effect of vascular brachytherapy. The double blind randomised trials based on Iridium-192 brachytherapy (manual loading) have all a significant angiographic reduction in restenosis rate at 6 months follow up for lesion lengths < 50 mm. the most notable of them are the following: SCRIPPS I (single centre): restenotic native coronary arteries or saphenous venous grafts (SVG) in 55 patients from 54% to 17% (9), reduction rate of 68%; GAMMA I (multicentre): in-stent restenosis of coronary arteries in 252 patients from 56% to 34%, (3) reduction rate of 39%. WRIST (single centre): in-stent restenosis of coronary arteries and SVG in 130 patients from 58% to 19% (16), reduction rate of 67%. The clinical outcome was also significantly improved, although the difference was mostly less pronounced. Clinical outcome was measured by major adverse cardiac events (MACE), which included the need for target lesion and vessel revascularisation and myocardial infarction . Table 32.6: Results from intracoronory trials: A. Gamma, B. Beta

Study

Design

Lesion Type

Centering

Device

Dose [Gy]

Patients

Restenosis PTCA/PTCA+BT

SCRIPPS I

single center double blind muliti-center Phase III single center

in-stent +50% de-novo

no

Ir-192 seed ribbon Ir-192 seed ribbon Ir-192 seed ribbon

8-30 to EEL IVUS based 8-30 to EEL IVUS based 15 at 2 or 2.4 mm

55

3 years 48 / 15 % 6 months 56 / 34 % 6 months 58 / 19 %

GAMMA 1

in-stent

no

252

WRIST

in-stent

no

130

Table 32.6.A: Gamma Trials

Study

Design

Lesion Type

Centering

Device

Dose [Gy]

Patients

Restenosis PTCA/PTCA+BT

BETA WRIST

single center non- randomized multi-center Phase III multi-center Phase II multi-center Phase III multi-center Phase III

in-stent

yes

Y-90 Boston- Scientific Sr-90/Y-90 Novoste Y-90 Boston- Scientific

20.6 at r+1 mm

50

6 months 22 % 6 months 45 / 29 %

START

in-stent

no

16 or 20 at 2 mm

476

Dose finding Study

de-novo +28% stent PTCA only

yes

9,12,15,18 at r+1 mm

181

6 months 29/21/16/15 % 28/17/16/4 %

INHIBIT

in-stent

yes

P-32 Guidant

20 at r+1 mm 16 or 20 at 2 mm

332

9 months 52/26 % 36 / 21 % 35 / 45 %

BETA CATH

de-novo PTCA only + stent

no

Sr-90/Y-90 Novoste

504 452

Table 32.6.B: Beta Trials

For intravascular brachytherapy based on beta sources the results reported in the early experience have been less favourable. The first Geneva study proved feasiblity using the Schneider-Sauerwein- Boston Scientific System (Yttrium-90, centring balloon), but showed no apparent effectiveness in de- novo lesions (11). The multicentre Geneva dose - finding study revealed a significant reduction of