title: Serial intravascular ultrasound assessment of the efficacy of intracoronary gamma-radiation therapy for preventing recurrence in very long, diffuse, in-stent restenosis lesions.
abstract: BACKGROUND
  The efficacy of coronary gamma-irradiation in preventing recurrent in-stent restenosis (ISR) is well established. However, brachytherapy may be less effective in very long, diffuse ISR lesions.
  
  
  RESULTS
  We used serial intravascular ultrasound (IVUS) to study patients with long, diffuse ISR lesions (length, 36 to 80 mm) who were enrolled in (1) Long WRIST (Washington Radiation In-Stent Restenosis Trial), a double-blind, placebo-controlled trial of intracoronary gamma-irradiation (15 Gy at 2 mm from the source) and (2) high-dose (HD) Long WRIST, a registry that used a dose prescription of 18 Gy at 2 mm from the source. IVUS was performed using automated pullback (0.5 mm/s). Stent, lumen, and intimal hyperplasia were measured at 2-mm intervals. Complete postintervention and follow-up IVUS imaging was available in 30 irradiated and 34 placebo patients from Long WRIST and in 25 patients from HD Long WRIST. Stent length was longer in HD Long WRIST than in placebo or treated patients in Long WRIST (P=0.0064 and P=0.0125, respectively). Otherwise, baseline measurements were similar. At follow-up, the minimum lumen area was largest in the HD Long WRIST patients (4.0+/-1.4 mm(2)); areas were 2.9+/-1.0 mm(2) in irradiated patients in Long WRIST and 1.9+/-1.1 mm(2) in placebo patients in Long WRIST (P<0.005 for all comparisons).
  
  
  CONCLUSIONS
  - Serial IVUS analysis shows that gamma-irradiation reduces recurrent in-stent neointimal hyperplasia in long, diffuse ISR lesions; however, it is even more effective when given at a higher dose.
authors.affiliation: Intravascular Ultrasound Imaging and Cardiac Catheterization Laboratories, Cardiovascular Research Institute, Washington Hospital Center, Washington, DC 20010, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Ahmed
authors.forename: G S
authors.initials: GS
authors.lastname: Mintz
authors.forename: R
authors.initials: R
authors.lastname: Waksman
authors.forename: R
authors.initials: R
authors.lastname: Mehran
authors.forename: B
authors.initials: B
authors.lastname: Leiboff
authors.forename: A D
authors.initials: AD
authors.lastname: Pichard
authors.forename: L F
authors.initials: LF
authors.lastname: Satler
authors.forename: K M
authors.initials: KM
authors.lastname: Kent
authors.forename: N J
authors.initials: NJ
authors.lastname: Weissman
mesh_terms: D001918:Brachytherapy / Q000379:methods; D003327:Coronary Disease / Q000601:surgery; D004307:Dose-Response Relationship, Radiation; D004311:Double-Blind Method; D005720:Gamma Rays / Q000627:therapeutic use*; D006083:Graft Occlusion, Vascular / Q000145:classification / Q000175:diagnosis / Q000517:prevention & control*; D006801:Humans; D008875:Middle Aged; D009204:Myocardial Revascularization / Q000009:adverse effects / Q000379:methods; D012307:Risk Factors; D055502:Secondary Prevention; D015607:Stents / Q000009:adverse effects; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional; D014654:Vascular Patency / Q000528:radiation effects