使用多细胞球体估算宽剂量范围内碳离子束的相对生物效应值

ESTIMATION OF RBE VALUES FOR CARBON-ION BEAMS IN THE WIDE DOSE RANGE USING MULTICELLULAR SPHEROIDS.

作者信息

Matsumoto Yoshitaka, Furusawa Yoshiya, Aoki-Nakano Mizuho, Matsufuji Naruhiro, Hirayama Ryoichi, Kanai Tatsuaki, Ando Koichi, Sakurai Hideyuki

机构信息

Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan.

Proton Medical Research Center, University of Tsukuba Hospital, 2-1-1 Amakubo, Tsukuba, Ibaraki, Japan.

出版信息

Radiat Prot Dosimetry. 2019 May 1;183(1-2):45-49. doi: 10.1093/rpd/ncy269.

DOI:10.1093/rpd/ncy269

PMID:30624731

Abstract

Hypofractionated carbon-ion therapy has been applied to treatment of several tumours. In this case, relative biological effectiveness (RBE) at high dose region must be considered, however, the RBE calculated physically has been not verified biologically. In this study, spheroid technique was adopted to estimate RBE in wide dose range. Cells were irradiated with X-rays and heavy-ions with LET of 13, 35, 100 and 300 keV/μm with monolayer and spheroid condition. Surviving fractions in wide dose range (0-15 Gy) were obtained to combined monolayer with spheroid survival data. The linear-quadratic and multi-target single-hit equation fitted well in survival data at low dose, and high dose region, respectively. A multi-process equation showed best fitting for survival data in wide dose range. RBE values of heavy-ions could be estimated by combination of monolayer and spheroid data. The values converged at 1.1-1.4 and varied by LET values at high and low dose region, respectively.

摘要

大分割碳离子疗法已应用于多种肿瘤的治疗。在这种情况下，必须考虑高剂量区域的相对生物效应（RBE），然而，物理计算的RBE尚未得到生物学验证。在本研究中，采用球体技术在宽剂量范围内估算RBE。细胞在单层和球体条件下接受X射线和线能量转移（LET）分别为13、35、100和300 keV/μm的重离子照射。通过合并单层和球体存活数据，获得了宽剂量范围（0-15 Gy）内的存活分数。线性二次方程和多靶单击方程分别在低剂量和高剂量区域的存活数据中拟合良好。一个多过程方程对宽剂量范围内的存活数据拟合最佳。重离子的RBE值可以通过单层和球体数据的组合来估算。这些值在高剂量和低剂量区域分别收敛于1.1-1.4，并随LET值而变化。