Department of Radiology, The No. 1 Hospital of China Medical University, Shenyang, China.
J Neurosurg. 2011 Jun;114(6):1672-80. doi: 10.3171/2011.1.JNS101513. Epub 2011 Feb 25.
In this paper, the authors' aim was to use CT perfusion imaging to evaluate the early changes in tumor microcirculation following radiosurgery in rat C6 brain gliomas.
C6 glioma cells were inoculated into the right caudate nucleus of 25 Wistar rats using a stereotactic procedure. Tumor-bearing rats were randomly divided into 2 groups (tumor group and treatment group). Rats in the treatment group received maximal doses of 20 Gy delivered by the X-knife unit 16 days postimplantation. Computed tomography perfusion imaging was performed in all rats 3 weeks after tumor implantation prior to death and histopathological analysis.
Hypocellular regions and tumor edema were increased in the treatment group compared with the tumor group. Parameters of CT perfusion imaging including cerebral blood volume (CBV) and mean transit time (MTT) of the tumors as well as the permeability surface area (PSA) product in the tumor-brain districts were decreased in the treatment group compared with the tumor group (p < 0.05). Although microvascular density (MVD) in the periphery of the tumors in the treatment group was higher than that in the normal contralateral brain (p < 0.05), MVD of the tumors in the treatment group was less than that in the tumor group (p < 0.01). There was a positive correlation between cerebral blood flow (CBF) and MVD as well as CBV and MVD in the center and periphery of tumors in both groups (p < 0.05).
A decrease in the perfusion volume of rat C6 brain gliomas was observed during the acute stage following X-knife treatment, and CBF and CBV were positively correlated with MVD of rat C6 brain gliomas. Thus, CT perfusion imaging can be used to evaluate the early changes in tumor microcirculation following radiosurgery.
本研究旨在利用 CT 灌注成像评估大鼠 C6 脑胶质瘤放射外科治疗后肿瘤微循环的早期变化。
立体定向技术将 C6 胶质瘤细胞接种于 25 只 Wistar 大鼠右侧尾状核。荷瘤大鼠随机分为两组（肿瘤组和治疗组）。治疗组大鼠在植入后 16 天接受最大剂量 20 Gy 的 X-刀治疗。所有大鼠在肿瘤植入后 3 周行 CT 灌注成像检查，然后处死行病理分析。
与肿瘤组相比，治疗组肿瘤细胞减少区域和肿瘤水肿增加。与肿瘤组相比，治疗组肿瘤的 CT 灌注成像参数包括脑血容量（CBV）和平均通过时间（MTT）以及肿瘤-脑区的通透性表面积（PSA）产物均降低（p<0.05）。虽然治疗组肿瘤边缘的微血管密度（MVD）高于对侧正常脑（p<0.05），但治疗组肿瘤的 MVD 低于肿瘤组（p<0.01）。两组肿瘤中心和边缘的脑血流量（CBF）与 MVD 以及 CBV 与 MVD 之间均呈正相关（p<0.05）。
X-刀治疗后大鼠 C6 脑胶质瘤的灌注量在急性期减少，CBF 和 CBV 与大鼠 C6 脑胶质瘤的 MVD 呈正相关。因此，CT 灌注成像可用于评估放射外科治疗后肿瘤微循环的早期变化。
