If you or someone you know has had cancer, then you know how frightening and painful treatment can be.
如果你或你认识的人得了癌症，你就会知道治疗的过程是何其的可怕和痛苦。
But during the past few decades doctors have developed apromising new procedure called proton therapy that could revolutionize the way wefight cancer.
但是在过去的几十年里医生们已经研发出一种新的有前景的治疗过程，叫做质子治疗。
Proton therapy is basically a new kind of radiation treatment.
质子治疗可以彻底改变我们对抗癌症的方法。
Until recently, allradiation therapy used X-Rays.
质子治疗从根本上说是放射疗法的一种。
X-Rays are good at destroying cancer cells, but theproblem is that when they pass through the body, they attack not only cancer cellsbut also surrounding healthy cells.
直到最近，所有的放射疗法都是采用的X射线。X射线能够摧毁癌细胞，但问题是当穿过身体时，它们不仅攻击癌细胞，也同样会攻击周围的健康细胞。
So doctors have been forced to use radiation doses low enough to minimize damage to non-cancerous cells.
所以医生们一直被迫使用较低的辐射剂量来减少对非癌细胞的伤害。
Proton therapy is a more accurate way of attacking cancer with radiation.
质子疗法是用辐射治疗癌症一种更为准确的方法。
Unlike X-Rays, which go through a patient and out the other side, protons penetrate only to the desired point and then stop.
与X射线不同的是，穿过病人身体并从身体的另一边出去时，质子只会穿透所需要的点，然后就停止。
So cells deeper in the body than where the tumor is are not affected.
因此，在人体内比肿瘤位置更深的细胞不会受到影响。
Protons also release most of their destructive energy just before they stop, sohealthy cells in front of the tumor get less radiation than the cancer cells do.
质子一停下来就会释放大部分的破坏性能量，所以肿瘤外部的健康细胞比癌细胞受到的辐射少。
Protontherapy's accuracy means that doctors can train high doses of proton radiation on tumors without worrying about causing collateral damage.
质子治疗的精确性意味着医生们可以在肿瘤的治疗上使用高剂量的质子辐射，并且不用担心会引起附带损害。
Proton radiation is not a miracle cure–in fact, it's limited to treating localizedcancers that have not spread throughout the body.
质子放射疗法其实并不是一个治疗的奇迹。它仅局限于治疗没有扩散到全身各处的局部肿瘤。
Still, it's an important new toolfor battling a deadly disease, especially for tumors deep inside the head or neck,where doing surgery would be too risky.
不过它仍然是一个对抗致命疾病的重要工具，特别是对于头部和颈部深处的肿瘤，在那里做手术太冒险了。
