Department of Biomedical Imaging and Radiological Sciences, School of Biomedical Science and Engineering, National Yang-Ming University, Taipei, Taiwan.
Int J Nanomedicine. 2012;7:723-30. doi: 10.2147/IJN.S28503. Epub 2012 Feb 13.
The purpose of this study was to evaluate the permeability of the blood-brain barrier after sonication by pulsed high-intensity focused ultrasound and to determine if such an approach increases the tumor:ipsilateral brain permeability ratio.
F98 glioma-bearing Fischer 344 rats were injected intravenously with Evans blue with or without blood-tumor barrier disruption induced by transcranial pulsed high-intensity focused ultrasound. Sonication was applied at a frequency of 1 MHz with a 5% duty cycle and a repetition frequency of 1 Hz. The permeability of the blood-brain barrier was assessed by the extravasation of Evans blue. Contrast-enhanced magnetic resonance images were used to monitor the gadolinium deposition path associated with transcranial pulsed high-intensity focused ultrasound, and the influencing size and location was also investigated. In addition, whole brain histological analysis was performed. The results were compared by two-tailed unpaired t-test.
The accumulation of Evans blue in brains and the tumor:ipsilateral brain permeability ratio of Evans blue were significantly increased after pulsed high-intensity focused ultrasound exposure. Evans blue injection followed by sonication showed an increase in the tumor:ipsilateral brain ratio of the target tumors (9.14:1) of about 2.23-fold compared with the control tumors (x4.09) on day 6 after tumor implantation. Magnetic resonance images showed that pulsed high-intensity focused ultrasound locally enhances the permeability of the blood-tumor barrier in the glioma-bearing rats.
This method could allow enhanced synergistic effects with respect to other brain tumor treatment regimens.
本研究旨在评估脉冲高强度聚焦超声（HIFU）致声击穿后血脑屏障的通透性，并确定该方法是否能增加肿瘤：同侧脑通透性比值。
F98 神经胶质瘤荷瘤 Fischer 344 大鼠静脉注射伊文思蓝，或在经颅脉冲高强度聚焦超声致血脑屏障破坏后注射。超声频率为 1MHz，占空比为 5%，重复频率为 1Hz。采用伊文思蓝渗出评估血脑屏障通透性。对比增强磁共振成像用于监测与经颅脉冲高强度聚焦超声相关的钆沉积路径，并研究其影响大小和位置。此外，还进行了全脑组织学分析。采用双尾非配对 t 检验比较结果。
脉冲高强度聚焦超声暴露后，脑内伊文思蓝蓄积和伊文思蓝的肿瘤：同侧脑通透性比值明显增加。与对照组肿瘤（x4.09）相比，在肿瘤植入后第 6 天，伊文思蓝注射后加超声处理的靶肿瘤（9.14:1）的肿瘤：同侧脑比值增加约 2.23 倍。磁共振成像显示，脉冲高强度聚焦超声局部增强了荷瘤大鼠血脑肿瘤屏障的通透性。
该方法可增强与其他脑肿瘤治疗方案的协同作用。
