van den Aardweg G J, Hopewell J W, Whitehouse E M, Calvo W
CRC Normal Tissue Radiobiology Research Group, University of Oxford, Churchill Hospital, UK.
Int J Radiat Oncol Biol Phys. 1994 Jul 1;29(4):763-70. doi: 10.1016/0360-3016(94)90564-9.
The development of an experimental model of radiation-induced myelopathy in the pig which would facilitate the study of the effects of clinically relevant treatment volumes.
The effects of local spinal cord irradiation, to a standard 10 x 5 cm field, have been evaluated in mature (37-42.5 weeks) and immature (15.5-23 weeks) pigs. Irradiation was with single doses of 60Co gamma-rays at a dose-rate of 0.21-0.65 Gy/min. The incidence of paralysis was used as an endpoint.
Irradiation of mature animals resulted in the development of frank paralysis with animals showing combined parenchymal and vascular pathologic changes in their white matter. These lesions, in common with those seen in patients, had a clear evidence of an inflammatory component. The latency for paralysis was short, 7.5-16.5 weeks, but within the wide range reported for patients. However, it was shorter than that reported in other large animal models. The ED50 value (+/- SE) for paralysis was 27.02 +/- 0.36 Gy, similar to that in rats taking into account dose-rate factors. The irradiation of immature pigs only resulted in transient neurological changes after doses comparable to those used in the mature animals, ED50 value (+/- SE) 26.09 +/- 0.37 Gy. The reasons for these transient neurological symptoms are uncertain.
A reliable experimental model of radiation-induced myelopathy has been developed for mature pigs. This model is suitable for the study of clinically relevant volume effects.
建立猪辐射诱导性脊髓病的实验模型，以促进对临床相关治疗体积效应的研究。
在成熟（37 - 42.5周）和未成熟（15.5 - 23周）猪中评估了对标准10×5 cm野进行局部脊髓照射的效果。照射采用单剂量60Coγ射线，剂量率为0.21 - 0.65 Gy/min。将瘫痪发生率作为终点指标。
对成熟动物进行照射导致明显瘫痪，动物白质出现实质和血管的联合病理变化。这些病变与患者所见病变一样，有明显的炎症成分证据。瘫痪潜伏期短，为7.5 - 16.5周，但在患者报告的较宽范围内。然而，它比其他大型动物模型报告的潜伏期短。考虑剂量率因素后，瘫痪的ED50值（±标准误）为27.02 ± 0.36 Gy，与大鼠相似。对未成熟猪进行照射，在给予与成熟动物相同剂量后仅导致短暂的神经学变化，ED50值（±标准误）为26.09 ± 0.37 Gy。这些短暂神经症状的原因尚不确定。
已为成熟猪建立了可靠的辐射诱导性脊髓病实验模型。该模型适用于研究临床相关的体积效应。
