Hartl Brad A, Ma Htet S W, Hansen Katherine S, Perks Julian, Kent Michael S, Fragoso Ruben C, Marcu Laura
a Department of Biomedical Engineering , University of California Davis , Davis , CA , USA.
b Department of Surgical and Radiological Sciences , University of California Davis School of Veterinary Medicine , Davis , CA , USA.
Int J Radiat Biol. 2017 Jul;93(7):676-682. doi: 10.1080/09553002.2017.1297902. Epub 2017 Mar 17.
To provide a comprehensive understanding of how the selection of radiation dose affects the temporal and spatial progression of radiation-induced necrosis in the rat model.
Necrosis was induced with a single fraction of radiation exposure, at doses ranging between 20 and 60 Gy, to the right hemisphere of 8-week-old Fischer rats from a linear accelerator. The development and progression of necrosis in the rats was monitored and quantified every other week with T1- and T2-weighted gadolinium contrast-enhanced MRI studies.
The time to onset of necrosis was found to be dose-dependent, but after the initial onset, the necrosis progression rate and total volume generated was constant across different doses ranging between 30 and 60 Gy. Radiation doses less than 30 Gy did not develop necrosis within 33 weeks after treatment, indicating a dose threshold existing between 20 and 30 Gy.
The highest dose used in this study led to the shortest time to onset of radiation-induced necrosis, while producing comparable disease progression dynamics after the onset. Therefore, for the radiation-induced necrosis rat model using a linear accelerator, the most optimum results were generated from a dose of 60 Gy.
全面了解辐射剂量的选择如何影响大鼠模型中辐射诱导坏死的时间和空间进展。
使用直线加速器对8周龄的Fischer大鼠右半球进行单次辐射暴露，剂量范围为20至60 Gy，诱导坏死。每隔一周通过T1加权和T2加权钆对比增强MRI研究监测和量化大鼠坏死的发生和进展。
发现坏死开始时间与剂量相关，但在最初发病后，坏死进展率和产生的总体积在30至60 Gy的不同剂量范围内是恒定的。小于30 Gy的辐射剂量在治疗后33周内未发生坏死，表明在20至30 Gy之间存在剂量阈值。
本研究中使用的最高剂量导致辐射诱导坏死的发病时间最短，同时在发病后产生相当的疾病进展动态。因此，对于使用直线加速器的辐射诱导坏死大鼠模型，60 Gy的剂量产生了最理想的结果。
