Development of a Rabbit Model of Radiation-Induced Sciatic Nerve Injury. Issue 4 (July 2015)

• Record Type: Journal Article
• Authors: Wan, Qi; Zeng, Qian; Li, Xinchun; Sun, Chongpeng; Zhou, Jiaxuan; Zou, Qiao; Deng, Yingshi; Niu, Daoli
• Is Part Of: Journal of computer assisted tomography. Volume 39:Issue 4(2015)
• Publication Date: 2015-07
• Subjects: Tomography -- Periodicals; Tomography -- Periodicals; Tomography; Periodicals; 616.0757
• DOI: 10.1097/RCT.0000000000000241
• Languages: English
• ISSNs: 0363-8715

Abstract

<abstract> <title> <x xml:space="preserve">Abstract</x> </title> <sec> <title>Objectives</title> <p>To develop a rabbit model of radiation-induced sciatic nerve injury (RISNI), using computed tomography (CT)–guided stereotactic radiosurgery, and assess the value of <italic>T</italic><sub>2</sub> measurements of injured nerves.</p> </sec> <sec> <title>Materials and Methods</title> <p>Twenty New Zealand rabbits were randomly divided into A (n = 5) and B (n = 15) groups. Group A rabbits underwent CT and magnetic resonance scan and were then killed for comparison of images and anatomy of sciatic nerves. One side of the sciatic nerve of group B rabbits received irradiation doses of 35, 50, or 70 Gy (n = 5 per group). Magnetic resonance imaging and functional assessments were performed before irradiation and 1, 2, 3, and 4 months thereafter.</p> </sec> <sec> <title>Result</title> <p>The thigh section of the sciatic nerve outside the pelvis could be observed by CT and magnetic resonance imaging. <italic>T</italic><sub>2</sub> values of the irradiated nerve of the 35-Gy group increased gradually, peaking at 4 months; <italic>T</italic><sub>2</sub> values of the 50-Gy group increased faster, peaking at 3 months. Significant differences between the 35-Gy and control groups were found at 3 and 4 months, and between the 50-Gy and control groups at 2, 3, and 4 months. Functional scores of the 50-Gy group declined progressively, whereas the 35-Gy group scores reached a low point at 3 months posttreatment and then recovered. Functional scores of the irradiated limbs demonstrated a negative correlation with <italic>T</italic><sub>2</sub> values (<italic>r</italic> = −0.591 and −0.595, <italic>P</italic> < 0.05). Electron microscopy revealed progressive deformation and degeneration of the irradiated nerve in the 35- and 50-Gy groups, which were more severe in the 50-Gy group.</p> </sec> <sec> <title>Conclusions</title> <p>A rabbit RISNI model can be produced using the midthigh segment of the sciatic nerve and single-fraction doses of 35 and 50 Gy. Although <italic>T</italic><sub>2</sub> values are useful for monitoring RISNI, they may not be sensitive enough to evaluate its severity.</p> </sec> </abstract>