Proton Therapy Prostate Cancer Treatment

Fight Prostate Cancer with Laser-Like Precision

California Protons’ director, Carl Rossi, MD, is internationally recognized for personally treating more than 10,000 prostate cancer patients with proton radiation therapy over the last 26 years—more than any other physician in the world.

Compared with older passive-scattering proton therapy treatment, our pencil beam scanning technology precisely delivers proton radiation treatment for prostate cancer with unmatched precision and the utmost care. It enables our physicians to attack prostate tumors, layer-by-layer, with high-dose radiation and minimize exposure to unaffected areas. This is important for prostate cancer patients who may face the risk of erectile dysfunction, decreased testosterone levels, urinary and rectal problems and gastrointestinal disorders due to radiation. The reduction of radiation-related toxicity also increases the likelihood that patients can complete treatment with fewer interruptions or delays.

Proton Therapy for Prostate
Cancer Treatment Details

What We Treat

  • Early stage prostate cancer
  • Locally advanced prostate cancer (Stage III and IV)
  • Some cases of metastatic cancer
  • Recurrent cancer

What We Do

  • Target the tumor only
  • Protect fragile healthy tissues, your rectum, bladder and bowel
  • Maintain your quality of life during treatment
  • Reduce side effects, including lowered testosterone levels, urinary and rectal problems, and gastrointestinal disorders
  • Lower the risk of secondary cancer due to radiation

SpaceOAR® Hydrogel – Spacing Organs at Risk

In an effort to minimize unnecessary radiation, unwanted side effects and potential injury to the rectum during prostate cancer therapy re-treatments and other special situations, we give patients the option of hydrogel. California Protons now offers this minimally invasive procedure to inject the hydrogel in our facility. Once in place, it typically cannot be felt and acts as a 1.3cm spacer1 to push the rectum away from the prostate. The spacer remains in place for three months before being fully absorbed and naturally cleared in your urine.

Procedural success rate2

Adverse device events2

Benefits of Proton Therapy for Prostate Cancer

Proton Beam Therapy for Prostate Cancer in San Diego

  • Our pencil beam scanning technology precisely controls protons to place the Bragg peak—the point at which they deposit their maximum energy—directly in the prostate tumor. This allows us to treat more complex tumor shapes and vary the dose within the tumor.
  • Advanced proton therapy allows doctors to more selectively deliver high-dose radiation to cancerous prostate gland cells, and reduce the dose to surrounding healthy tissues and critical organs. In some cases, this has been shown to deliver higher cure rates than X-ray radiation treatment even in some of the most challenging situations. In one study, 97 percent of 4,000 proton therapy patients had not suffered a recurrence; many of the cancer-free patients had completed treatment as long as 10 years earlier.3
  • Reduced prostate cancer treatment side effects and no effect on testosterone levels. A 2013 study found no significant changes in testosterone levels in low- and intermediate-risk prostate cancer patients.4 Another study found significantly lower radiation exposure to the rectum and bladder with proton therapy than with X-ray radiation, which has been shown to reduce the chances of developing urinary and bowel problems.5
  • Shortened prostate cancer treatment time, higher doses, lower costs and less disruption to a patient’s life with hypofractionation treatment. Multiple trials in both the U.S. and UK have shown that hypo fractionation (4 to 6 weeks of treatment) is just as effective as 8 to 9 weeks and no more toxic to healthy tissue.
  • Unlike with older technology, the treatment plan can be loaded into the computer and completed within a matter of minutes. Treatments for prostate cancer are also non-invasive and convenient so patients can get back to their daily activities quicker.

Prostate Cancer Stages
& Treatment


The stage of prostate cancer is one of the most important factors in selecting treatment. Depending on the stage, combined treatments of surgery, radial prostatectomy, brachytherapy, hormone therapy, chemotherapy and radiation therapy may be needed for some prostate tumors. Treatment options also are affected by the type of prostate cancer, age, overall health and personal preferences.

At stage I, prostate cancer is found in the prostate gland only. Radiation therapy for stage I prostate cancer is often recommended to reduce the risk of cancer spreading, especially for those with higher Gleason scores and PSA levels.

At stage II, prostate cancer is more advanced than in stage I, but has not spread outside the prostate. Stage II is divided into stages IIA (half or less of a lobe) and IIB (half or more of a lobe). At this stage of prostate cancer, both surgery and radiation therapy are treatment options. Radiation therapy may still be recommended after surgery to further reduce the risk of cancer spreading or returning.

Stage III prostate cancer has spread beyond the outer layer of the prostate and may have spread to the seminal vesicles. Surgery and radiation therapy with hormonal therapy are curative treatment options at this stage of prostate cancer. Radiation therapy may still be needed after surgery to provide additional local and distant cancer control.

Stage IV prostate cancer may have spread beyond the seminal vesicles to nearby tissue or organs, such as the bladder, rectum or lymph nodes. At this stage, treatment of the whole body with hormonal therapy or systemic therapy is the mainstay of treatment. Local therapy with surgery or radiation therapy may be needed to help control symptoms. Proton radiation treatment may be used for advanced or late-stage prostate cancer to shrink tumors or control pain.

Treatment for
Recurrent Prostate Cancer

Proton therapy is often the best way to treat recurrent tumors in areas that have previously been treated with radiation therapy.

Treating previously irradiated areas can be challenging. The healthy tissues around the recurrent tumor do not fully “forget” the previous radiation dose, and any added dose continues to increase the risk of normal tissue injury. Proton beam therapy may enable doctors to better concentrate the dose to the target and limit it elsewhere, allowing re-treatment with radiation in select patients.

Prostate Cancer Treatment Outcomes
& Long-Term Effects

Proton therapy treatment for prostate cancer at California Protons Cancer Therapy Center in San Diego may offer similar outcomes to standard X-ray radiation, while reducing long-term and potentially life-threatening side effects such as erectile dysfunction, lowered testosterone levels, urinary and rectal problems, and gastrointestinal disorders due to radiation damage to the rectum, bowel and bladder. It also offers the possibility of lower chances for secondary cancers later in life due to the reduced radiation exposure to healthy tissues and organs.

However, all cancer treatments have advantages and disadvantages. Be sure to discuss all of the potential risks, as well as treatment options for prostate cancer, with your oncologist or urologist.

I have experienced absolutely no side effects from my treatments. I coached my men’s and women’s cross-country teams throughout my treatments, without missing a single day. I’ve maintained the intimacy I value so much with my wife, JoAnn, and remain active as a father and mentor in the community.
Steve Scott
Prostate Cancer Patient

Research Studies Supporting Proton Therapy for Prostate Cancer

About Proton Therapy

Coverage Options