Williams J P, Eagleton M, Hernady E, Schell M, Illig K, Green R, Rubin P
Department of Radiation Oncology, University of Rochester Medical Center, New York, USA.
Cardiovasc Radiat Med. 1999 Jul-Sep;1(3):257-64. doi: 10.1016/s1522-1865(99)00016-5.
From the clinical oncologic experience, fractionation of the radiation dose offers a better therapeutic window, both with respect to effectiveness and unwanted side effects. Thus, we undertook a pilot study in a rodent model, using a single dose of 15 Gy compared with fractionation schedules of 5 or 10 daily applications of 3 Gy.
Using a previously described rat angioplasty model, animals were randomly assigned to one of four groups: unilateral balloon injury, sham irradiation; unilateral balloon injury, bilateral 15 Gy single dose irradiation; unilateral balloon injury, bilateral 3 Gy x 5 daily fractions; or unilateral balloon injury, bilateral 3 Gy x 10 daily fractions.
All three radiation groups demonstrated a clear inhibition of neointimal hyperplasia. We therefore offer evidence for the effectiveness of fractionated radiation as a means to inhibit vascular restenosis in a rat carotid model. However, the 3 Gy x 5 schedule was less effective than either the 3 Gy x 10 schedule or the 15 Gy single dose. This study must be repeated using longer time points to provide proof of principle.
从临床肿瘤学经验来看，辐射剂量的分次给予在有效性和不良副作用方面都提供了更好的治疗窗口。因此，我们在啮齿动物模型中开展了一项试点研究，将单次15 Gy剂量与每日3 Gy、分5次或10次给予的分次方案进行比较。
利用先前描述的大鼠血管成形术模型，将动物随机分为四组之一：单侧球囊损伤、假照射；单侧球囊损伤、双侧单次15 Gy照射；单侧球囊损伤、双侧每日3 Gy、分5次照射；或单侧球囊损伤、双侧每日3 Gy、分10次照射。
所有三个辐射组均显示出对内膜增生的明显抑制。因此，我们为分次辐射作为抑制大鼠颈动脉模型中血管再狭窄的一种手段的有效性提供了证据。然而，3 Gy×5的方案不如3 Gy×10的方案或15 Gy单次剂量有效。本研究必须使用更长的时间点重复进行以提供原理证明。
