Evaluation of the relative biological effectiveness of spot-scanning proton irradiation in vitro.
Evaluation of the relative biological effectiveness of spot-scanning proton irradiation in vitro.
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DOI：
10.1093/jrr/rrv101
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发表时间：
2016-06
影响因子：
2
通讯作者：
Shirato H
中科院分区：
文献类型：
--
作者：
Maeda K;Yasui H;Matsuura T;Yamamori T;Suzuki M;Nagane M;Nam JM;Inanami O;Shirato H
相对生物学有效性（RBE）从固定值1.1的变化是至关重要的质子束治疗。到目前为止，研究估计RBE在多个位置相对于扩展布拉格峰（SOBP）已主要使用被动散射方法进行，有限的数据可用于点扫描光束。因此，为了研究点扫描束的RBE，使用北海道大学医院质子治疗中心的束线照射中国仓鼠成纤维细胞V79细胞。将细胞放置在六个不同的深度，包括质子束的入口和SOBP的近端和远端部分。使用集落形成测定分析存活细胞级分，并且通过使用线性二次模型拟合的曲线获得细胞存活曲线。在SOBP的中心，RBE 10和RBE 37分别为1.15和1.21。相反，远端区域显示出较高的RBE值（RBE 10为1.50，RBE 37为1.85）。这些结果与以前使用被动散射质子束进行的研究结果一致。总之，这些数据强烈表明，在治疗计划的点扫描光束以及被动散射质子束的RBE的变化应予以考虑。
Variations in relative biological effectiveness (RBE) from a fixed value of 1.1 are critical in proton beam therapy. To date, studies estimating RBE at multiple positions relative to the spread-out Bragg peak (SOBP) have been predominantly performed using passive scattering methods, and limited data are available for spot-scanning beams. Thus, to investigate the RBE of spot-scanning beams, Chinese hamster fibroblast V79 cells were irradiated using the beam line at the Hokkaido University Hospital Proton Therapy Center. Cells were placed at six different depths, including the entrance of the proton beam and the proximal and distal part of the SOBP. Surviving cell fractions were analyzed using colony formation assay, and cell survival curves were obtained by the curve fitted using a linear–quadratic model. RBE10 and RBE37 were 1.15 and 1.21 at the center of the SOBP, respectively. In contrast, the distal region showed higher RBE values (1.50 for RBE10 and 1.85 for RBE37). These results are in line with those of previous studies conducted using passive scattering proton beams. Taken together, these data strongly suggest that variations in RBE should be considered during treatment planning for spot-scanning beams as well as for passive scattering proton beams.