What is proton therapy?

Proton therapy is a type of radiation treatment. Radiation therapy is used to treat many types of cancer, including prostate cancer. It can be used as the primary therapy, but is often combined with other treatments.

In conventional radiation, high-energy X-rays are used to target and destroy cancer cells in the prostate. But as the X-rays pass through your body, they can damage healthy tissue. This can expose nearby organs, such as the bladder and rectum, to complications. However, most modern facilities offer a more refined version of conventional radiation therapy called intensity modulated radiation therapy (IMRT), which is designed to cause less damage to surrounding tissues.

In proton therapy, radiation is delivered in proton beams. The key difference is that proton beams stop once they’ve delivered their energy to the target. This allows more precise targeting of cancer cells while delivering less radiation to healthy tissue.

Anyone who can have radiation therapy can have proton therapy. It can be used as primary treatment for early-stage prostate cancer or as part of a total treatment plan for prostate cancer.

Which treatment you should have isn’t as simple as comparing proton therapy to chemotherapy, surgery, or hormone treatments. Each serves a specific purpose.

Your treatment will depend, in large part, on how aggressive the cancer is and its stage at diagnosis. Other considerations are previous treatments, age, and other health conditions that might make certain treatments intolerable. Proton therapy is also more expensive, may not be covered by insurance, is not widely available, and has not yet been studied in larger trials comparing it to other types of radiation. Your doctor will look at the total picture when recommending treatment.

Radiation therapy

Proton therapy is just as effective as conventional radiation therapy. It’s less likely to damage other organs and produces fewer side effects. It also causes fewer side effects than chemotherapy or hormone therapy. It can be used as a first-line therapy or in conjunction with other treatments.


If the cancer hasn’t spread outside the prostate, surgery is a common choice because it may cure the cancer. This surgery can be performed abdominally, laparoscopically, or through the perinea.

Normal activities can be resumed within a few weeks. Side effects can include urinary incontinence and sexual dysfunction.

Hormone therapy

Hormone therapy can reduce male hormones that fuel prostate cancer. It’s usually used when cancer has spread outside the prostate or when prostate cancer returns after you’ve had other treatments. It’s also an option if you’re at high risk of recurrence or to shrink the tumor prior to radiation.

Side effects of hormone therapy include sexual dysfunction, shrinkage of testicles and penis, and loss of muscle mass.


Chemotherapy is not a standard treatment for early-stage prostate cancer. It might be an option if the cancer has spread outside the prostate and hormone treatment isn’t working. It’s unlikely to cure prostate cancer, but it can help slow progression. Among the potential side effects are fatigue, nausea, and hair loss.

Proton therapy facilities are growing in number, but the treatment is still not available everywhere. Your doctor can let you know if there’s a proton treatment center near you. If there is, there are a few things to think about in advance.

Treatment usually means going in five days a week for four to eight weeks, so you’ll want to clear your calendar. Although the actual treatment only takes a few minutes, you should probably block 45 minutes to an hour for the whole procedure.

Before you start treatment, you’ll have an initial consultation so the radiation team can get set up for future visits. Using a series of images and other data, they’ll determine exactly how you’ll need to be positioned during therapy. It may involve the use of customized immobilization devices. This can be an involved procedure, but it’s necessary to ensure that protons are delivered precisely to improve your outlook.

No other preparation is necessary.

Since delivering the protons to the cancer cells is the goal of therapy, a lot of time is spent on positioning your body and adjusting the equipment before each session.

You’ll have to remain perfectly still while the proton beam is delivered, but it will only take one to three minutes or so. It’s noninvasive and you won’t feel anything. You’ll be able to leave right away and resume your normal activities.

There are usually fewer side effects from proton therapy than there are from conventional radiation therapy. That’s because there’s less damage to healthy tissue around the tumor.

Side effects may include fatigue and skin redness or soreness at the treatment site. You may also have issues with incontinence or gastrointestinal side effects. Erectile dysfunction is another risk of radiation treatment. However, about 94 percent of men who have used proton therapy to treat prostate cancer report that they’re still sexually active after treatment.

Most people tolerate proton therapy very well, with little to no recovery time.

If you’ve been through first-line treatment, but still have cancer, your doctor will adjust your treatment accordingly.

After surgery, radiation, or chemotherapy, you may be told that you’re cancer free. But you’ll still need to be monitored for recurrence. If you’ve been taking hormone therapy, you may need to continue to do so.

Periodic PSA testing can help gauge effectiveness of hormone therapy. The pattern of PSA levels can also help monitor for recurrence.

The process of recovery is different for everyone. Much depends on the stage at diagnosis and the extent of treatment. Your age and general health also play a role. Your doctor will take all these factors into consideration to give you an idea of what to expect, including:

  • the schedule for follow-up exams and tests
  • how to deal with short- and long-term side effects
  • diet and other lifestyle recommendations
  • signs and symptoms of recurrence

Proton therapy is a newer treatment for prostate cancer with potentially fewer side effects, but it’s more expensive and not as easily available. Ask your doctor if proton therapy is a good option for you.