European Organization for Nuclear Research, Geneva, Switzerland. Ludwig-Maximilians-Universität München, Munich, Germany.
Phys Med Biol. 2018 Oct 26;63(21):215014. doi: 10.1088/1361-6560/aae431.
In the context of hadrontherapy, whilst ions are capable of effectively destroying radio resistant, deep seated tumors, their treatment localization must be well assessed to ensure the sparing of surrounding healthy tissue and treatment effectiveness. Thus, range verification techniques, such as online positron-emission-tomography (PET) imaging, hold great potential in clinical practice, providing information on the in vivo beam range and consequent tumor targeting. Furthermore, [Formula: see text] emitting radioactive ions can be an asset in online PET imaging, depending on their half-life, compared to their stable counterparts. It is expected that using these radioactive ions the signal obtained by a PET apparatus during beam delivery will be greatly increased, and exhibit a better correlation to the Bragg Peak. To this end, FLUKA Monte Carlo particle transport and interaction code was used to evaluate, in terms of annihilation events at rest and dose, the figure of merit in using [Formula: see text] emitter, radioactive ion beams (RI [Formula: see text]). For this purpose, the simulation results were compared with experimental data obtained with an openPET prototype in various online PET acquisitions at the Heavy Ion Medical Accelerator in Chiba (HIMAC), in collaboration with colleagues from the National Institute of Radiological Sciences' (NIRS) Imaging Physics Team. The dosimetry performance evaluation with FLUKA benefits from its recent developments in fragmentation production models. The present work estimated that irradiations with RI [Formula: see text], produced via projectile fragmentation and their signal acquisition with state-of-the-art PET scanner, lead to nearly a factor of two more accurate definition of the signals' peak position. In addition to its more advantageous distribution shape, it was observed at least an order magnitude higher signal acquired from C and O irradiations, with respect to their stable counterparts.
在粒子疗法中,虽然离子能够有效地破坏耐辐射的深层肿瘤,但为了确保周围健康组织不受损伤并达到治疗效果,必须对其治疗定位进行精确评估。因此,在线正电子发射断层扫描(PET)成像等射程验证技术在临床实践中具有很大的潜力,可提供有关体内束流射程和随后肿瘤靶向的信息。此外,[公式:见正文]放射性离子在在线 PET 成像中具有优势,这取决于它们的半衰期,与稳定的同类物相比。预计使用这些放射性离子,PET 仪器在束流输送过程中获得的信号将大大增加,并与布拉格峰更好地相关。为此,使用 FLUKA 蒙特卡罗粒子输运和相互作用代码,根据静止时的湮没事件和剂量,评估使用[公式:见正文]发射体、放射性离子束(RI[公式:见正文])的优点。为此,将模拟结果与与 National Institute of Radiological Sciences' (NIRS) Imaging Physics Team 的同事在 Chiba 的 Heavy Ion Medical Accelerator(HIMAC)进行的各种在线 PET 采集过程中使用开放 PET 原型获得的实验数据进行了比较。FLUKA 的剂量学性能评估得益于其在碎片产生模型方面的最新发展。本工作估计,通过射弹碎裂产生的 RI[公式:见正文]照射,并使用最先进的 PET 扫描仪进行信号采集,可使信号峰值位置的定义精度提高近两倍。除了其更有利的分布形状外,与稳定的同类物相比,还观察到 C 和 O 照射产生的信号至少高一个数量级。