I do not recommend proton beam radiation therapy to my patients.
I believe surgery is more effective than any form of radiation therapy for tumors that are confined to the prostate gland for several reasons.
One is that about 30% to 40% of tumors contain a few cells that are resistant to the doses of radiation that can be delivered safely to the prostate gland. Thus, if the prostate is removed, the patient is cured, but if it is treated with radiation, he may or may not be cured.
Second, patients treated initially with surgery who have a local recurrence can safely be treated with salvage radiation. The same is not true for patients who have had tumor recurrence after radiation. They cannot safely receive more radiation and salvage surgery is associated with a very high complication rate, because tissues do not heal well after they have received high doses of radiation.
Finally, all cancer is genetic in origin, and it is possible that the genetic alterations that caused the first cancer in the prostate gland could cause a second cancer elsewhere in the prostate. Thus, even if radiation cured the first cancer, the patient could develop a second cancer in the prostate, and there would be limited options to treat it. The patient could not safely have more radiation or surgery, and the best option would be hormonal therapy, which is not curative and which has side effects that are especially undesirable to younger men.
Keeping the above in mind, it is not possible to say that such treatment is not effective in all circumstances.
However, it is extremely expensive (often costing more than $100,000), currently available in only a few places in the United States, and, in my opinion, has little or nothing to offer over the more readily available and less expensive forms of external beam radiation therapy, such as 3-dimensional conformal radiation or intensity modulated radiation therapy (called IMRT).
All of these methods are forms of so-called “conformal” radiation that concentrate the radiation effects in and around the prostate gland, sparing, as much as possible, the rectum and bladder to avoid side effects. With proton beam radiation, the results are achieved with a beam of charged particles called protons that enter the body from the side and deposit their energy without passing out through the other side.