Actually I am not going to discuss solar wind here, although there IS a relationship. Photons from the sun reach the earth at the speed of light since they are wave form energy packets (feel free to delve into this here if you want to compete with Einstein…). Protons, being much larger, take longer and interact with earth’s ionosphere leading to the lovely aurora borealis. At the level of treating the prostate of course, there isn’t much difference in the timing of when your prostate might be getting whacked with energy from a source 5 feet away!
But there is a difference in reimbursement to the institution that owns the machine. The cost of a modern IMRT machine is about $1.5-3 million. For a cyclotron that can produce protons, the cost is 50 times as much. You can read about that in the Forbes article. The problem is who will pay for such a machine, and the answer is “you” either in your taxes (medicare, medicaid) or as insurance costs borne by you and everyone else in your plan. I have previously blogged about proton therapy for prostate cancer here (which I recommend you review if you haven’t read it) If there was a difference in outcomes (cure rates, side effects), the cost differential might be worth it. With modern photon machines, there is no meaningful difference in these outcomes. The wall street journal yesterday reported that insurance companies are dropping their coverage. Hopefully patients will realize that they are not being denied excellent therapy and accept the sad fact that the many institutions who have installed proton machines have done so largely as economic marketing moves, not as a means of improving patient care. There are a few instances where protons might indeed provide some advantages in treating cancer, but the only way to recoup the cost of these machines is to treat a more common condition such as prostate cancer. I presume we could get by with a couple of them in this country and not repeat our experience with every hospital buying a robot for surgery…but that is a different argument with a different decimal point on the costs of proliferating technology.