Blasting tumors with high-energy protons has become an increasingly popular and effective way of fighting cancer. Unlike the X rays normally used to fry the cancerous cells, proton beams can be tuned so that they deliver most of their energy to a specific target, without damaging the healthy tissue nearby. But the equipment required for proton therapy, which includes a particle accelerator, can take up an entire building and cost as much as $100 million. Now University of Wisconsin, Madison physicist Thomas Mackie says his company, TomoTherapy, is developing an effective, but smaller and less expensive proton generator in collaboration with scientists at Lawrence Livermore National Lab and the University of California, Davis. This new beam generator would use a di-electric wall accelerator, which uses powerful electric fields to speed up protons in short distances. Best of all, it could fit in today’s radiation treatment rooms, and would cost only about $20 million. Mackie guesses that clinical trials are still 5 years away.—Gregory Mone
(Image credit: Lawrence Livermore National Laboratory, TomoTherapy, and University of California, Davis)

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