Piersanti L, Bellini F, Bini F, Collamati F, De Lucia E, Durante M, Faccini R, Ferroni F, Fiore S, Iarocci E, La Tessa C, Marafini M, Mattei I, Patera V, Ortega P G, Sarti A, Schuy C, Sciubba A, Vanstalle M, Voena C
Laboratori Nazionali di Frascati dell'INFN, Frascati, Italy. Dipartimento di Scienze di Base e Applicate per Ingegneria, Sapienza Università di Roma, Roma, Italy.
Phys Med Biol. 2014 Apr 7;59(7):1857-72. doi: 10.1088/0031-9155/59/7/1857. Epub 2014 Mar 14.
The radiation used in hadrontherapy treatments interacts with the patient body producing secondary particles, either neutral or charged, that can be used for dose and Bragg peak monitoring and to provide a fast feedback on the treatment plans. Recent results obtained from the authors on simplified setups (mono-energetic primary beams interacting with homogeneous tissue-like target) have already indicated the correlation that exists between the flux of these secondaries coming from the target (e.g. protons and photons) and the position of the primary beam Bragg peak. In this paper, the measurements of charged particle fluxes produced by the interaction of a 220 MeV/u carbon ion beam at GSI, Darmstadt, with a polymethyl methacrylate target are reported. The emission region of protons (p), deuterons (d) and tritons (t) has been characterized using a drift chamber while the particle time-of-flight, used to compute the kinetic energy spectra, was measured with a LYSO scintillator. The energy released in the LYSO crystal was used for particle identification purposes. The measurements were repeated with the setup at 60° and 90° with respect to the primary beam direction. The accuracy on the fragments emission profile reconstruction and its relationship with the Bragg peak position have been studied. Based on the acquired experimental evidence, a method to monitor the dose profile and the position of the Bragg peak inside the target is proposed.
强子治疗中使用的辐射与患者身体相互作用，产生中性或带电的次级粒子，这些粒子可用于剂量和布拉格峰监测，并为治疗计划提供快速反馈。作者在简化设置（单能初级束与均匀组织样靶相互作用）上获得的最新结果已经表明，来自靶的这些次级粒子（例如质子和光子）的通量与初级束布拉格峰的位置之间存在相关性。本文报道了在达姆施塔特的GSI，用220 MeV/u碳离子束与聚甲基丙烯酸甲酯靶相互作用产生的带电粒子通量的测量结果。使用漂移室对质子（p）、氘核（d）和氚核（t）的发射区域进行了表征，同时用LYSO闪烁体测量了用于计算动能谱的粒子飞行时间。LYSO晶体中释放的能量用于粒子识别。在相对于初级束方向60°和90°的设置下重复测量。研究了碎片发射轮廓重建的精度及其与布拉格峰位置的关系。基于获得的实验证据，提出了一种监测靶内剂量轮廓和布拉格峰位置的方法。
