What is proton therapy?
Proton therapy for prostate cancer is a non-invasive treatment option that involves using a focused ray of proton particles to destroy cancerous tumors. The treatment is capable of delivering precise, high doses of radiation to accurately target cancer cells without causing significant damage to healthy tissue surrounding the prostate. With proton therapy, there are usually minimal to no side effects and generally patients have excellent disease-free survival rates.
The Difference Between Proton Radiation and Standard X-ray Radiation
There is a significant difference between standard photon (X-ray) radiation treatment and proton therapy. X-ray radiation can damage healthy tissues because the physician is unable to adequately conform the irradiation pattern to the cancer. As a result, healthy tissue and organs near the prostate may receive excess radiation which can cause damage and produce side effects.
The power of protons is that higher doses of radiation can be used to control and manage cancer while significantly reducing damage to healthy tissue and vital organs. With protons, doctors can direct the radiation to the tumor with pinpoint accuracy. This means less damage to surrounding healthy organs and tissue, and the ability to deliver a higher dose of radiation to the tumor.
How is proton therapy administered?
It may vary somewhat by proton treatment center, but usually there is a pre-treatment consult. An image of the prostate is produced by a CT scan. Some centers implant two or three gold fiducials (seeds). An immobilization device is fitted to the patient during the consult, and focusing devices may be custom built to help direct the beam to the precise target.
Again, it varies by proton treatment center, but typically during treatment the proton beam is focused on the prostate gland plus a small margin around the gland. Treating this extra margin helps to kill any cancer that may have escaped the gland. This margin of safety may include part of the rectum, which is adjacent to the prostate. At most proton centers, in order to protect the anterior(inside) wall of the rectum from radiation, a small, lubricated balloon is inserted into the rectum and inflated with a small amount of water prior to each treatment. A secondary function of the balloon is to help immobilize the prostate.
An individual proton treatment session lasts about 15-20 minutes and is administered five days per week for about 8 ½ weeks (unless you qualify for the shortened treatment protocol which can be done in roughly half this time). Treatments can be done early in the morning so that the patient has the rest of the day to himself to do whatever he wants. Since treatment is painless, the patient should feel fine to exercise, walk, hike, shop, etc…
The History of Proton Therapy
Proton therapy has been around for nearly 60 years; tens of thousands of patients have been treated - mostly prostate cancer patients; it is FDA approved, reimbursed by Medicare and about 150 private insurers. Reputable medical centers in the U.S. and around the world have embraced the technology and have built, or are building proton centers. The first proposal to use high-energy protons for medical treatment was in 1946. About 10 years later, proton treatment began for patients with certain cancers. All these early treatments were done in physics laboratories. Research and laboratory applications increased rapidly over the next 30 years. However, it was not until the James M. Slater, MD Proton Therapy and Research Center at Loma Linda University Cancer Center (LLUCC) became operational that the full benefits of proton therapy were available to cancer patients of all types.
Built by U.S. Department of Energy’s Fermi National Accelerator Laboratory (Fermilab) physicists and engineers, LLUCC’s accelerator is the world's smallest variable-energy proton synchrotron. Its design delivers a beam of energy sufficient to reach the deepest tumors in patients. Proton radiation treatment is notably valuable for treating localized, isolated, solid tumors that may spread to other areas of the body.
Questions about proton therapy? Just ask.