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Prostate Cancer

Proton Therapy for Prostate Cancer

Proton therapy is a non-surgical, non-invasive form of radiation therapy. Using pencil-beam technology, proton therapy precisely targets prostate cancer tumors while protecting healthy tissue and surrounding organs. This leads to fewer side effects during and after treatment, so you can continue enjoying life.

Thompson Proton Center is the ONLY proton therapy center in East Tennessee, allowing you to receive state-of-the-art care close to home.

About Prostate Cancer

  • Prostate cancer occurs when cells in the prostate (a gland in the male reproductive system) grow and multiply rapidly, causing damage to healthy tissue in and around the prostate.
  • Prostate cancer is the second most common cancer in men in the U.S. In fact, approximately 1 in 9 men will develop prostate cancer at some point in their life.
  • If found early enough, prostate cancer can be easily treated and cured. 

How Proton Therapy Works

Proton therapy can treat prostate cancer precisely while lowering the risk for side effects during and after treatment. 

Proton therapy uses charged particles (protons) rather than x-rays to destroy cancer cells. Protons can be focused directly on the tumor and stop at that target in the body. With extreme accuracy, proton therapy results in excellent rates of cancer control with a lower risk for side effects than other forms of radiation therapy. 

The controlled delivery and dosage of proton energy allows direct, customized targeting of the tumor, for the maximum prescribed dosage of radiation. These characteristics of proton therapy can benefit the patient:

  • Improved quality of life, during and after treatment, from greater precision in treating the tumor.
  • Lower risk of side effects and impact to bodily functions, as unnecessary radiation to nearby healthy tissue and vital organs is prevented.
  • Cancer in critical areas or close to organs and structures that could be damaged by radiation can be safely targeted and treated.
  • Patients with cancer recurrence, who have previously been treated with radiation can often safely and effectively be retreated with proton therapy to achieve local control. 

The physical properties of protons, described by the Bragg-Peak (Figure 1), and the increased conformality of pencil beam scanning to conform to the exact shape of the cancer, make it possible to spare healthy surrounding organs from exposure to unnecessary radiation. 

Proton therapy is able to deliver a more targeted dose of energy to the tumor site compared to traditional radiation therapy.
As shown here in the Bragg-Peak, proton therapy is able to deliver a more targeted dose of energy to the tumor site compared to traditional radiation therapy.
Radiation exposure for traditional radiation treatment versus proton therapy for prostate cancer patients.
Radiation Exposure in Proton Therapy vs. Traditional Radiation for Prostate Cancer Patients

Clinical Benefits of Proton Therapy in Prostate Cancer

  • 5% higher 5-year overall survival rate in intermediate risk (1)
  • Patients who received proton therapy report highest quality of life compared to surgery, x-ray, or brachytherapy patients (2)
  • 35% less radiation to the bladder and 59% less radiation to the rectum (3)
  • 42% reduction in relative risk of developing a secondary cancer (1)
  • 50% reduction in treatment-related bowel frequency and urgency at 2 years (4)
  • 21% lower risk of urinary toxicity at 2 years (5)
  • 25% lower risk of erectile dysfunction at 2 years (5)

NOTE: Sources available below. 

Download an information sheet about proton therapy for prostate cancer patients.

Learn More:

Thompson Proton Center

Frequently Asked Questions

What to Expect with Proton Therapy

Common Terms 




1.Hartsell W, Bentefour H, Dooling D,Mendenhall N. Proton Therapy Is Associated with Superior Survival and Decreased Risk of Complications Compared to IMRT for Intermediate
Risk Prostate Cancer: A Medicare/SEER Database Study.[abstract] Presented at PTCOG-NA October 25, 2017 at National Conference in Chicago. http://ptcog-na.org.
2. Bryant Research. Awareness and Impressions of Selected Prostate Cancer Treatment Options Survey. 2013.
3. Vargas C, Fryer A, Mahajan C, et al. Dose–volume comparison of proton therapy and intensity-modulated radiotherapy for prostate cancer. International Journal of Radiation Oncology • Biology • Physics. 2008;70;3;744 – 751
4. Hoppe BS, Michalski JM, Mendenhall NP, et al. Comparative effectiveness study of patient reported outcomes after proton therapy or intensity-modulated radiotherapy for prostate cancer. Cancer. 2014;120:1076-1082.
5. Pan H, Jiang J, Hoffman D, et. al. Comparative toxicities and cost of intensity-modulated radiotherapy, proton radiation, and sterotactic body radiotherapy among younger men with prostate cancer. Journal of Clinical Oncology. 2018;36;18;1823-1830.