by Susan Hardy
We can always kill cancer cells, says medical physicist Sha Chang. Always. It doesn’t matter where the tumor is.
The problem, of course, is that what kills the tumor can also kill the patient. Chang has spent 15 years trying to perfect external-beam radiation therapy—changing dosages, adjusting the angle of the beam—and she knows all too well that she’ll never get it right. The radiation will always damage healthy tissue.
That’s why she has another plan—one based on a discovery scientists made 50 years ago. There’s a way to deliver a high dose of radiation via thin x-ray microbeams, harming so little of the surrounding tissue that the body would barely notice. No one’s been doing this because no one had equipment that could produce the microbeams. Now, Chang and her colleagues have built a machine that can do it—and that they think may one day replace the radiation we use to destroy cancer.