RADIOBIOLOGICAL CHARACTERIZATION OF TWO THERAPEUTIC PROTON BEAMS WITH DIFFERENT INITIAL ENERGY SPECTRA USED AT THE INSTITUT CURIE PROTON THERAPY CENTER IN ORSAY
RADIOBIOLOGICAL CHARACTERIZATION OF TWO THERAPEUTIC PROTON BEAMS WITH DIFFERENT INITIAL ENERGY SPECTRA USED AT THE INSTITUT CURIE PROTON THERAPY CENTER IN ORSAY
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DOI：
10.1016/j.ijrobp.2010.09.003
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发表时间：
2011-11-15
影响因子：
7
通讯作者：
Megnin-Chanet, Frederique
中科院分区：
文献类型：
--
作者：
Calugaru, Valentin;Nauraye, Catherine;Megnin-Chanet, Frederique
目的：质子治疗中的治疗计划在整个产生的扩展布拉格峰（SOBP）中使用相对生物学效率（RBE）的通用值1.1。在这篇文章中，我们报告了奥赛居里研究所质子治疗中心用于治疗的76-和201-MeV质子束的SOBP中RBE随深度的变化。方法和材料：的RBE（相对于（137）Cs γ射线）在两个人肿瘤细胞中，使用克隆原细胞存活作为终点，的发生率的DNA双链断裂（DSBs）作为测量的脉冲场凝胶电泳没有和酶处理，以揭示集群lesions.Results：RBE诱导细胞杀伤的76 MeV的光束在SOBP的深度增加。然而，对于201 MeV的质子，它接近于（137）Cs伽马射线，并且没有显着变化。DSB和簇状病变的发生率为质子比（137）Cs γ射线，但并不依赖于质子的能量或在SOBP.Conclusions的位置：到现在为止，很少有人注意到的变化RBE与深度的SOBP作为一个函数的标称能量的初级质子束和DNA损伤的分子性质。在76 MeV SOBP的RBE增加意味着，在远端的肿瘤组织收到了更高的生物等效剂量比在近端，尽管均匀的物理剂量。这不是201 MeV能量束的情况。精确确定入射光束能量、调制和组织中深度对线性能量传递RBE关系的影响对于治疗计划至关重要。(C)2011 Elsevier Inc.
Purpose: Treatment planning in proton therapy uses a generic value for the relative biological efficiency (RBE) of 1.1 throughout the spread-out Bragg peak (SOBP) generated. In this article, we report on the variation of the RBE with depth in the SOBP of the 76- and 201-MeV proton beams used for treatment at the Institut Curie Proton Therapy Center in Orsay.Methods and Materials: The RBE (relative to (137)Cs gamma-rays) of the two modulated proton beams at three positions in the SOBP was determined in two human tumor cells using as endpoints clonogenic cell survival and the incidence of DNA double-strand breaks (DSBs) as measured by pulse-field gel electrophoresis without and with enzymatic treatment to reveal clustered lesions.Results: The RBE for induced cell killing by the 76-MeV beam increased with depth in the SOBP. However for the 201-MeV protons, it was close to that for (137)Cs gamma-rays and did not vary significantly. The incidence of DSBs and clustered lesions was higher for protons than for (137)Cs gamma-rays, but did not depend on the proton energy or the position in the SOBP.Conclusions: Until now, little attention has been paid to the variation of RBE with depth in the SOBP as a function of the nominal energy of the primary proton beam and the molecular nature of the DNA damage. The RBE increase in the 76-MeV SOBP implies that the tumor tissues at the distal end receives a higher biologically equivalent dose than at the proximal end, despite a homogeneous physical dose. This is not the case for the 201-MeV energy beam. The precise determination of the effects of incident beam energy, modulation, and depth in tissues on the linear energy transfer RBE relationship is essential for treatment planning. (C) 2011 Elsevier Inc.