Proton Therapy
质子疗法也叫质子刀，是放射治疗的一种，比普通的放射疗法更有针对性。质子作为带正电荷的粒子，以极高的速度进入人体，由于其速度快，在体内与正常组织或细胞发生作用的机会极低，当到达癌细胞的特定部位时，速度突然降低并停止，释放最大能量，发生Bragg峰（博拉格峰），将癌细胞杀死，同时有效地保护正常组织。由于质子治疗具有穿透性能强、剂量分布好、局部剂量高、旁散射少、半影小等特征，尤其对于治疗有重要组织器官包绕的肿瘤，显现出较大的优越性。质子治疗的适应症比拟广泛，对于脑部良恶性肿瘤、脊髓肿瘤、脑血管疾病、头颈部肿瘤、眼部病变、胸腹部肿瘤、儿科肿瘤以及其它疾病等均有较好的疗效。国外临床治疗数据标明，质子治疗肿瘤有效率达到95%以上，五年存活率高达80%，被高能物理界和医学界评估为疗效最好、副作用最少的治疗方法。
Doctors have developed a promising new procedure that could (1)revolutionize the way we fight cancer. Learn about proton therapy on this Moment of Science.
If you or someone you know has had cancer, then you know how frightening and painful treatment can be. But during the past few decades doctors have developed a promising new procedure called proton therapy that could revolutionize the way we fight cancer.
Proton therapy is basically a new kind of radiation treatment. Until recently, all radiation therapy used X-Rays. X-Rays are good at destroying cancer cells, but the problem is that when they pass through the body, they attack not only cancer cells but also surrounding healthy cells. So doctors have been forced to use radiation doses low enough to minimize damage to non-cancerous cells.
Proton therapy is a more accurate way of attacking cancer with radiation. Unlike X-Rays, which go through a patient and out the other side, protons penetrate only to the desired point and then stop. So cells deeper in the body than where the tumor is are not affected.
Protons also release most of their destructive energy just before they stop, so healthy cells in front of the tumor get less radiation than the cancer cells do. Proton therapy’s accuracy means that doctors can train high doses of proton radiation on (2)tumors without worrying about causing (3)collateral damage.
Proton radiation is not a miracle cure–in fact, it’s limited to treating (4)localized cancers that have not spread throughout the body. Still, it’s an important new tool for battling a deadly disease, especially for tumors deep inside the head or neck, where doing surgery would be too risky.
译文：
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。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。质子治疗可以彻底改变我们对抗癌症的方法。
质子治疗从根本上说是放射疗法的一种。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。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。
质子疗法是用辐射治疗癌症一种更为准确的方法。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。因此，在人体内比肿瘤位置更深的细胞不会受到影响。
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。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。
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。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。
Notes:
(1)revolutionize [,rev?'lju:??naiz] vt.发动革命；彻底改革；宣传革命 vi.革命化；从事革命
1.They wanted to revolutionize the whole world.
他们要在全世界发动革命。
2.But the Internet has just as much potential to revolutionize education.
不过，互联网同样具有实现教育革命的潜力。
(2)tumors n.肿瘤（tumor的复数）
(3)collateral damage [法]附带损害
The collateral damage is still considerable.
间接的损失仍然相当大。
(4)localized['l?uk?laizd] adj.局部的；地区的；小范围的 v.定位（localize的过去分词）
Their interest localized on the development of this new drug.
他们的兴趣集中在这种新药的研制开发上。 |