Basic research to sonodynamic therapy for the brain tumor

声动力学方法已被提出用于治疗脑肿瘤。在临床应用之前，进行了研究以澄清声动力学方法是否可能在正常脑中引起组织损伤，并证明其对大鼠实验性脑肿瘤的有效性。1)在大鼠的正常脑组织中，使用或不使用Rosebengal的聚焦超声辐照诱导了局部破坏性损伤，损伤的发生与超声强度和辐照时间成正比。2)聚焦超声照射区域内的病灶在聚焦于基底节时呈离散性，组织学检查可见凝固性坏死。Rosebengal给药后，病变变大并伴有局灶性出血。3)组织损伤的机制主要是由于与超声辐照有关的热效应，因为脑温 ...更多信息 在超声辐照过程中，温度显著升高。超声辐照后，给予Rosebengal后的病变比不给予Rosebengal时的病变更大，因此病变是由空化效应和热效应诱导的，因为在给予和不给予Rosebengal的辐照之间未观察到脑温差异。4)使用Rosebengal时，伊文思蓝增强的病变比不使用Rosebengal时更大，因此表明声化学活性导致血脑屏障开放。5)超声强度为100 W/cm ^2，持续5分钟，引起破坏性损伤，1小时和24小时后的损伤相同。照射强度为24 W/cm ^2，照射5 min，2个月后未发现破坏性或脱髓鞘病变。6)在大鼠脑肿瘤的声化学效应方面，强制照射后肿瘤变为梭形或新月形，因此表明给予Rosebengal后肿瘤缩小更为显著。这些结果表明，声动力学治疗是有效的治疗脑肿瘤的大鼠。声动力学疗法是近年来发展起来的脑肿瘤治疗方法之一，也可应用于术中声动力学照射治疗残留肿瘤。少

A sonodynamic approach has been proposed for the treatment of brain tumors. Prior to clinical application, investigations were made to clarify whether or not the sonodynamic approach might induce tissue damage in the normal brain and demonstrate how effective it was on experimental brain tumor in rats. 1) In the normal brain tissue of rats, focused ultrasound irradiation with or without Rosebengal induced localized destructive lesions and the occurrence or lesions was proportional to the intensity of the ultrasound and the irradiation time. 2) The lesions which coincidentally occurred in the area irradiated with focused ultrasound, was discrete when focusing on the basal ganglia and coagulation necrosis was observed in the histological examination. After Rosebengal was administered, the lesions became larger and associated with focal hemorrhage. 3) The mechanism of tissue damage was considered to mainly be due to the heat effect relation to ultrasound irradiaton, because the brain temp … More erature increased remarkably during ultrasound irradiation. Following ultrasound irradiation, the lesions became larger with Rosebengal administration than without Rosebengal, and thus the lesions were induced with a cavitation effect as well as a heat effect, because no difference was observed in the brain temperature between irradiation with and without Rosebengal. 4) The lesions enhanced by Evans blue became larger with Rosebengal than without Rosebengal, thus suggesting an opening of the blood brain barrier due to sonochemical activity. 5) The intensity of ultrasound, which induced destructive lesions, was of 100 w/cm^2 for 5 minutes and the lesion was the same after 1 hour and 24 hours. With an irradiation intensity of 24 w/cm^2 for 5 minutes, none of the destructive or demyelinating lesions were found 2 months later. 6) In terms of the sonochemical effect to brain tumors in rats, the tumors turned into either a fusiform or a crescent after forcused irradiation, thus suggesting a reduction in the tumor which was more significant after Rosebengal administration. These results indicated that sonodynamic therapy was thus effective for the treatment of brain tumors in rats. Sonodynamic therapy is one of newly developed treatment modalities for brain tumors and it might be also applicable to residual tumors by means of intraoperative sonodynamic irradiation. Less