Intracoronary radiation therapy using a novel beta emitter for in-stent restenosis Tungsten WRIST.
BACKGROUND
Intracoronary beta-radiation therapy reduces in-stent restenosis (ISR). We aimed to determine the safety and feasibility of intracoronary radiation therapy (IRT) utilizing tungsten (188W), a beta emitter.


METHODS
A total of 30 patients with angiographic evidence of ISR in a previously treated native coronary artery underwent percutaneous coronary intervention (PCI; balloon angioplasty, ablation by atherectomy, or laser angioplasty). After the intervention, a noncentered delivery catheter with a side guide 0.014-in. wire carrying a tungsten (188W) coil, with an active length of 33 mm, was inserted. Patients were randomized to a radiation dose of 18, 22, or 25 Gy at 2 mm from the center of the source. Aspirin and Plavix, at 300 mg loading dose, were administered prior to intervention. Plavix 75 mg/day was prescribed for 6 months after the procedure.


RESULTS
At 6 months follow-up, the overall binary angiographic restenosis rate was 18.8%. Target vessel revascularization (TVR) was 23% and target lesion revascularization related major adverse cardiac events (TLR-MACE) was 13.3%, without any intergroup differences. A comparison with the original Washington Radiation for In-stent restenosis Trial (WRIST) radiation cohort utilizing an 192Iridium source (prescription dose 15 Gy at 2 mm from the source) showed similar TVR and TLR-MACE rates of 30% and 18%, respectively. The TVR and TLR-MACE rates in the WRIST placebo cohort were 70% and 66%, respectively.


CONCLUSIONS
Vascular brachytherapy with tungsten (188W) is feasible and safe. The 6-month clinical outcomes are similar to the original WRIST radiation group.
Dilcher
Christian
C
Division of Cardiology, Washington Hospital Center, Washington, DC, USA.
Satler
Lowell F
LF
Pichard
Augusto D
AD
Kent
Kenneth M
KM
Porrazzo
Michael
M
Chan
Rosanna
R
Torguson
Rebecca
R
Canos
Daniel A
DA
Waksman
Ron
R
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage; D001241:Aspirin / Q000008:administration & dosage; D001610:Beta Particles / Q000009:adverse effects / Q000627:therapeutic use; D001918:Brachytherapy / Q000379:methods*; D000077144:Clopidogrel; D015331:Cohort Studies; D017023:Coronary Angiography / Q000379:methods; D004307:Dose-Response Relationship, Radiation; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006083:Graft Occlusion, Vascular / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization / Q000379:methods; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage; D011868:Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D015607:Stents; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D016896:Treatment Outcome; D014414:Tungsten / Q000009:adverse effects / Q000627:therapeutic use*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D010975:Platelet Aggregation Inhibitors; D011868:Radioisotopes; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin; D014414:Tungsten