title: External beam irradiation in angioplasted arteries of hypercholesterolemic rabbits. The dose and time effect.
abstract: OBJECTIVE
  To study the dose and time effect of external beam irradiation on the morphometry of both angioplasted and nonangioplasted arteries in a hypercholesterolemic rabbit model.
  
  
  METHODS
  Eight groups of rabbit femoral arteries were studied: arteries (a) with no intervention, (b) irradiated with a 12-Gy 6 MV X-ray dose, (c) with a 18-Gy, (d) treated with balloon angioplasty, (e) dosed with 12-Gy half an hour post-angioplasty, (f) dosed with 18-Gy half an hour post-angioplasty, (g) dosed with 12-Gy 48 h post angioplasty, (g) dosed with 18-Gy 48 h post angioplasty.
  
  
  RESULTS
  External irradiation at either 12 or 18 Gy was not found to change vessel morphometry in noninjured arteries. The 12-Gy dose given soon after angioplasty further increased percentage stenosis (63% on the average), despite the preservation of the lumen cross-sectional area. Positive remodeling was not observed in arteries given 18-Gy half an hour post angioplasty to counterbalance the increased neointimal formation. Therefore, this treatment resulted in a drastic reduction in lumen area and in enhancement of percentage stenosis (84% on the average). On the contrary, the delayed irradiation of the angioplasted arteries at either 12 or 18 Gy was not found to influence any of the studied morphometric parameters 5 weeks after angioplasty.
  
  
  CONCLUSIONS
  Uniform external beam irradiation up to 18 Gy was well tolerated by intact femoral arteries. Prompt 12- or 18-Gy irradiations accentuated percentage stenosis. However the lumen cross-sectional area was preserved only at the lower dose point. Delayed irradiation at any dose did not influence the restenosis process.
authors.affiliation: Department of Medical Physics, Medical School, University of Ioannina, 451-10, Ioannina, Greece. jkalef@cc.uoi.gr
authors.forename: J
authors.initials: J
authors.lastname: Kalef-Ezra
authors.forename: L K
authors.initials: LK
authors.lastname: Michalis
authors.forename: V
authors.initials: V
authors.lastname: Malamou-Mitsi
authors.forename: P
authors.initials: P
authors.lastname: Tsekeris
authors.forename: C
authors.initials: C
authors.lastname: Katsouras
authors.forename: A
authors.initials: A
authors.lastname: Boziari
authors.forename: I
authors.initials: I
authors.lastname: Toumpoulis
authors.forename: G
authors.initials: G
authors.lastname: Bozios
authors.forename: A
authors.initials: A
authors.lastname: Charchanti
authors.forename: D A
authors.initials: DA
authors.lastname: Sideris
mesh_terms: D000800:Angioplasty, Balloon; D000818:Animals; D001157:Arterial Occlusive Diseases / Q000209:etiology; D004195:Disease Models, Animal; D004307:Dose-Response Relationship, Radiation; D005263:Femoral Artery / Q000528:radiation effects* / Q000601:surgery*; D006937:Hypercholesterolemia / Q000150:complications / Q000628:therapy*; D008297:Male; D011183:Postoperative Complications / Q000209:etiology; D011817:Rabbits; D011879:Radiotherapy Dosage; D013997:Time Factors; D016896:Treatment Outcome; D017539:Tunica Intima / Q000528:radiation effects / Q000601:surgery; D017540:Tunica Media / Q000528:radiation effects / Q000601:surgery; D014964:X-Ray Therapy