Prompt gamma imaging of proton pencil beams at clinical dose rate
Prompt gamma imaging of proton pencil beams at clinical dose rate
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DOI：
10.1088/0031-9155/59/19/5849
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发表时间：
2014-10-07
影响因子：
3.5
通讯作者：
Stappen, F. Vander
中科院分区：
文献类型：
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作者：
Perali, I.;Celani, A.;Stappen, F. Vander
在这项工作中，我们提出了一个即时伽玛相机的实时质子束范围验证的实验结果。该检测系统采用像素化的铈掺杂的镥基闪烁晶体，耦合到硅光电倍增器阵列，由专用电子设备读出。瞬发伽马相机使用刀口狭缝准直器在闪烁探测器上产生目标中的束路径的1D投影。我们设计的探测器提供高计数统计和高的光探测效率的几个MeV的瞬发γ射线。狭缝设计有利于计数统计，并且在简单性、降低的成本和有限的占地面积方面可能是有利的。我们提出的描述实现伽马相机，以及相机本身的成像性能方面的表征的结果。我们还提出了在质子治疗中心用质子笔束照射聚甲基丙烯酸甲酯体模的实验结果。使用钨狭缝准直器，并在3-6 MeV能量范围内获得瞬发伽马射线。用在100 MeV、160 MeV和230 MeV下操作的束进行采集，在喷嘴出口处具有几nA的束电流。测得的瞬发伽马分布与模拟一致，我们分别在100、160和230 MeV下用0.5 x 10（8）、1.4 x 10（8）和3.4 x 10（8）质子实现了4 mm的位移恢复精度（2 sigma）。我们的结论是，即时伽玛配置文件的质子束在体内范围验证与开发的伽玛相机和狭缝准直器的收购是可行的，在临床条件下。相机的紧凑设计允许其集成在质子治疗室中，并且将进行进一步的研究以验证在真实的患者的治疗期间使用该检测系统。
In this work, we present experimental results of a prompt gamma camera for real-time proton beam range verification. The detection system features a pixelated Cerium doped lutetium based scintillation crystal, coupled to Silicon PhotoMultiplier arrays, read out by dedicated electronics. The prompt gamma camera uses a knife-edge slit collimator to produce a 1D projection of the beam path in the target on the scintillation detector. We designed the detector to provide high counting statistics and high photo-detection efficiency for prompt gamma rays of several MeV. The slit design favours the counting statistics and could be advantageous in terms of simplicity, reduced cost and limited footprint. We present the description of the realized gamma camera, as well as the results of the characterization of the camera itself in terms of imaging performance. We also present the results of experiments in which a polymethyl methacrylate phantom was irradiated with proton pencil beams in a proton therapy center. A tungsten slit collimator was used and prompt gamma rays were acquired in the 3-6 MeV energy range. The acquisitions were performed with the beam operated at 100 MeV, 160 MeV and 230 MeV, with beam currents at the nozzle exit of several nA. Measured prompt gamma profiles are consistent with the simulations and we reached a precision (2 sigma) in shift retrieval of 4 mm with 0.5 x 10(8), 1.4 x 10(8) and 3.4 x 10(8) protons at 100, 160 and 230 MeV, respectively. We conclude that the acquisition of prompt gamma profiles for in vivo range verification of proton beam with the developed gamma camera and a slit collimator is feasible in clinical conditions. The compact design of the camera allows its integration in a proton therapy treatment room and further studies will be undertaken to validate the use of this detection system during treatment of real patients.