A narrow microbeam is more effective for tumor growth suppression than a wide microbeam: an in vivo study using implanted human glioma cells.
A narrow microbeam is more effective for tumor growth suppression than a wide microbeam: an in vivo study using implanted human glioma cells.
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DOI：
10.1107/s090904951101185x
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发表时间：
2011-07
影响因子：
2.5
通讯作者：
Kohmura E
中科院分区：
文献类型：
--
作者：
Uyama A;Kondoh T;Nariyama N;Umetani K;Fukumoto M;Shinohara K;Kohmura E
对于微束放射治疗，窄微束比宽微束更有效。微束放射治疗和最近提出的微束放射治疗治疗脑肿瘤的杀瘤机制尚不清楚。此外，在波束几何形状的各种参数中，改变波束宽度的影响是未知的。在这项研究中，使用两种不同宽度的微束对植入小鼠体内的人脑胶质瘤细胞的肿瘤生长抑制进行了实验评估：传统的窄束（20 µm宽，100 µm中心距）和宽束（100 µm宽，500 µm中心距）。 比较肿瘤生长率，并对急性细胞死亡进行组织学研究。在交叉平面照射的情况下，20 µm微束照射后第4 - 28天肿瘤生长受到显著抑制，而100 µm微束照射后第4 - 18天肿瘤生长受到抑制，但不显著。 TUNEL染色的免疫组织化学显示，在照射后24和72小时，无论是微束TUNEL阳性细胞没有增加。 发现20 μm微束比100 μm微束更具有杀肿瘤作用，并且该作用与凋亡细胞死亡无关。 潜在的机制可能是功能性组织退化，而不是光束路径中的直接细胞损伤。
A narrow microbeam is shown to be more effective than a wide microbeam for microbeam radiation therapy. The tumoricidal mechanisms of microbeam radiation therapy, and the more recently proposed minibeam radiation therapy, for the treatment of brain tumors are as yet unclear. Moreover, from among the various parameters of beam geometry the impact of changing the beam width is unknown. In this study, suppression of tumor growth in human glioma cells implanted in mice was evaluated experimentally using microbeams of two different widths: a conventional narrow beam (20 µm width, 100 µm center-to-center distance) and a wide beam (100 µm width, 500 µm center-to-center distance). The tumor growth ratio was compared and acute cell death was studied histologically. With cross-planar irradiation, tumor growth was significantly suppressed between days 4 and 28 after 20 µm microbeam irradiation, whereas tumor growth was suppressed, and not significantly so, only between days 4 and 18 after 100 µm microbeam irradiation. Immunohistochemistry using TUNEL staining showed no increase in TUNEL-positive cells with either microbeam at 24 and 72 h post-irradiation. The 20 µm microbeam was found to be more tumoricidal than the 100 µm microbeam, and the effect was not related to apoptotic cell death. The underlying mechanism may be functional tissue deterioration rather than direct cellular damage in the beam path.