Laboratori Nazionali del Sud dell'INFN, Catania, Italy.
Phys Med Biol. 2012 Sep 21;57(18):5667-78. doi: 10.1088/0031-9155/57/18/5667. Epub 2012 Aug 31.
Hadrontherapy is an emerging technique in cancer therapy that uses beams of charged particles. To meet the improved capability of hadrontherapy in matching the dose release with the cancer position, new dose-monitoring techniques need to be developed and introduced into clinical use. The measurement of the fluxes of the secondary particles produced by the hadron beam is of fundamental importance in the design of any dose-monitoring device and is eagerly needed to tune Monte Carlo simulations. We report the measurements carried out with charged secondary particles produced from the interaction of a 80 MeV/u fully stripped carbon ion beam at the INFN Laboratori Nazionali del Sud, Catania, with a poly-methyl methacrylate target. Charged secondary particles, produced at 90° with respect to the beam axis, have been tracked with a drift chamber, while their energy and time of flight have been measured by means of a LYSO scintillator. Secondary protons have been identified exploiting the energy and time-of-flight information, and their emission region has been reconstructed backtracking from the drift chamber to the target. Moreover, a position scan of the target indicates that the reconstructed emission region follows the movement of the expected Bragg peak position. Exploiting the reconstruction of the emission region, an accuracy on the Bragg peak determination in the submillimeter range has been obtained. The measured differential production rate for protons produced with E(Prod)(kin) > 83 MeV and emitted at 90° with respect to the beam line is dN(P)/(dN(C)dΩ) (E(Prod)(kin) > 83 MeV, θ = 90°) = (2.69 ± 0.08(stat) ± 0.12(sys)) × 10⁻⁴ sr⁻¹.
强子疗法是一种新兴的癌症治疗技术，它使用带电粒子束。为了满足强子疗法在将剂量释放与癌症位置匹配方面的改进能力，需要开发和引入新的剂量监测技术。在任何剂量监测设备的设计中，测量强子束产生的次级粒子的通量都至关重要，并且迫切需要调整蒙特卡罗模拟。我们报告了在 INFN Laboratori Nazionali del Sud，Catania 用 80 MeV/u 全剥离碳离子束与聚甲基丙烯酸甲酯靶相互作用产生的带电次级粒子进行的测量。带电次级粒子在与束轴成 90°的方向上产生，并用漂移室进行跟踪，同时用 LYSO 闪烁体测量它们的能量和飞行时间。利用能量和飞行时间信息识别出次级质子，并从漂移室到靶回溯重建它们的发射区域。此外，对目标的位置扫描表明，重建的发射区域跟随预期布拉格峰位置的移动。利用发射区域的重建，获得了亚毫米范围内布拉格峰确定的精度。用 E(Prod)(kin) > 83 MeV 产生并在与束线成 90°的方向上发射的质子的测量微分产额率为 dN(P)/(dN(C)dΩ) (E(Prod)(kin) > 83 MeV, θ = 90°) = (2.69 ± 0.08(stat) ± 0.12(sys)) × 10⁻⁴ sr⁻¹。
