Proton beam therapy and prostate cancer
- Prostate cancer is the most commonly diagnosed cancer in men.
- Radiation therapy is an excellent treatment option for men with prostate cancer.
- Proton beam therapy is becomingly increasingly used for prostate cancer but the benefits are not clear.
What is proton beam therapy?
Proton beam therapy is a form of radiation therapy known as external beam radiation therapy. Proton radiation therapy is becoming increasingly used to treat cancers across the United States as the number of cancer centers offering this technology has greatly increased over the past several decades. Dr. James Brooks, Chief Urologic Oncology at Stanford Medicine says:
Read More“proton beam therapy is a relatively new form of radiation that’s marketed heavily.” Proton radiation, as the name implies, uses protons that are sped up extremely fast and then precisely delivered to the tumor. When these particles reach the tumor, they deliver energy to the DNA causing damage that kills the tumor cells.
This is similar to the more commonly used photon form of radiation therapy but has several potential advantages over photon radiation treatments. The main theoretical advantage of proton radiation is that less radiation dose is given to normal healthy tissue around the tumor compared with photon radiation treatments. The reason why is deep in physics and beyond the scope of this article, but it is related to the physical properties of a proton compared to the light nature of a photon. Suffice it to say protons can be used to effectively treat cancer and in some scenarios (like treating kids) may have advantages over photon-based treatments.
Is proton beam better for prostate cancer?What is most important to know is that radiation therapy is an excellent treatment choice for prostate cancer of all stages regardless of if it is with photons or protons. Radiation is extremely effective and often can be delivered with minimal side effects. Radiation treatment and surgery are both equally effective treatments for prostate cancer.
Currently, there is no high-quality evidence or data to suggest proton radiation treatment is better than the more traditional photon-based radiation treatments. Certainly, there appears to be no advantage in curing the cancer as traditional radiation treatment has excellent cure rates, and using protons would not be expected to increase this rate.
The theoretical advantage of proton therapy for treating prostate cancer is to reduce side effects. Again, there is no great data to suggest using proton radiation for prostate cancer reduces side effects. This may be because traditional photon radiation for prostate cancer has significantly advanced over the same time. There are many new techniques, such as stereotactic body radiotherapy (SBRT) and advanced radiation delivery mechanisms that use photons that have significantly reduced the side effects of this form of treatment. New procedures such as rectal spacer placement have also decreased the side effect burden of traditional photon-based radiation treatments.
There are a few important things to note about proton therapy for prostate cancer. Although the advantages of proton therapy for prostate cancer are debatable it is still a commonly used and very effective form of treatment for prostate cancer. There is also significant debate among radiation oncologists on who is the best candidate for proton therapy and when to use protons in treating prostate cancer. Given the debate around proton therapy for prostate cancer, you should get an opinion from a center that uses protons to better understand if it is right for you.
What to expect when getting treated?
Whether you are being treated with protons or photons the process and expectations are very similar. Radiation will typically be delivered every day Monday-Friday with the weekends off to rest. The radiation is delivered from the outside of the body and is entirely non-invasive. During the treatment, you will not see anything, feel anything, or notice anything at all. Each day you will travel to the radiation center and lay flat on a table with a custom mold (like a small bean bag) designed specifically for your body and placed around your hips The mold is made to keep you from moving while the radiation treatment is being delivered. Once the treatment is complete you can go about your daily activity as normal without restrictions.
The treatment time will vary depending on what type of radiation treatment you are having. Traditional radiation using photons is very quick and may only require 10-15 minutes each day. More sophisticated radiation techniques like SBRT or protons may require more time each day to complete treatment. Many factors determine how long treatment may last but typically is never longer than 30 minutes each day.
The take-home message.
When diagnosed with prostate cancer there are many excellent treatment options including radiation therapy. The most common type of radiation used is external beam radiation with photons. Recently, more patients are being treated using external beam radiation with protons but the advantages of this form of treatment are debated. Whether you choose photon or proton-based radiation treatment you should expect good outcomes as both forms of radiation are excellent treatment options for prostate cancer. If you are considering proton-based radiation, we have a simple recommendation- get an opinion at a center that offers protons and a center that does not offer protons. Currently, there are many more options with traditional photon-based radiation treatments compared with protons so it is important to understand your options and the risks and benefits of both approaches.