浅谈医用轻离子束设备的发展

Discussion on the Performance Characteristics of Medical Light Ion Beam Equipment

重离子和质子都属于"粒子治疗"。质子治疗其实就是"轻离子治疗",利用较轻质量的离子,如重氢、氦、锂来治疗算"轻离子治疗";重离子治疗就是利用质量较重又适合肿瘤治疗的离子来进行治疗,如碳、氮、氧均算"重离子治疗"。医用轻离子束治疗设备庞大,包括加速器和束流传输系统、旋转机架(或固定机架)、治疗头、图像引导系统、治疗控制系统、治疗计划系统、患者虚拟定位系统等。所谓质子治疗,就是将失掉电子的氢原子原子核,利用回旋加速器或者同步加速器加速到光速约70%,将原子核快速的穿透到人体内部,到达指定部位,通过能量守恒原理将速度突然降低并停止,释放出最大能量,产生"布拉格峰",将癌细胞杀死,同时有效地保护周围正常组织,且副作用小。例如当肿瘤直接与重要器官相邻时,质子治疗能有效地治疗肿瘤部位,并尽可能的减小伤害这些重要器官或部位的功能,这在常规辐射治疗中是不可能的。

Both heavy ions and protons belong to"particle therapy",and proton therapy is actually"light ion therapy".The use of lighter weight ions,such as heavy hydrogen,helium,and lithium,is called"light ion therapy".Heavy ion therapy is to use heavy ions which are suitable for tumor treatment.For example,carbon,nitrogen and oxygen are regarded as"heavy ion therapy".Medical light ion beam treatment equipment is huge,including accelerator and beam transmission system,rotating frame(or fixed frame),treatment head,image guidance system,treatment control system,treatment planning system,patient virtual positioning system,etc.The so-called proton therapy is to accelerate the hydrogen atomic nucleus that loses electrons to about 70%of the speed of light by using cyclotron or synchrotron,penetrate into the human body at this extremely fast speed,reach the specific part where the cancer cells are,suddenly reduce and stop,release the maximum energy,generate"Bragg peak",kill the cancer cells,and effectively protect the surrounding areas Normal tissue with little side effect.For example,when the tumor is directly adjacent to important organs or structures such as spinal cord,optic nerve,heart,etc.,proton therapy can still effectively treat the tumor while protecting the function of these important organs or structures,which is impossible in conventional radiation therapy.