When considering cancer treatment, side effects and outcomes are of major concern. A non-invasive treatment, proton therapy has become a trusted method for accurately targeting tumors and minimizing damage to healthy tissues, thus having a positive impact on reduced side effects and improved quality of life.


For more information on Tennessee’s first proton therapy facility, click here.


Proton therapy is an advanced form of radiation therapy that uses a single beam of high-energy protons to treat various forms of cancer. Just as with conventional radiation therapy, protons treat tumors by directing radiation into the tumor site where doses of radiation destroy cancerous cells.


However, unlike conventional radiation therapy, in which x-ray beams deposit their energy into the healthy tissue before and after the tumor site, physicians can control the timing and dosage of energy from protons, which allows the maximum energy deposited directly into the tumor, reducing damage to nearby healthy tissue and thus limiting negative side effects.

Unlike proton therapy, conventional radiation therapy uses x-rays which enter and exits the body, potentially causing damage to the healthy tissue that surrounds the tumor being treated. However, at the Provision Center for Proton Therapy, our pencil beam scanning capabilities allow our oncologists to target treatment to a specific area, giving a high-energy dose of protons that enter the tumor with accuracy and stop in their tracks, limiting collateral damage to healthy tissues. As a result, the important organs and tissues surrounding the cancer are better protected from unnecessary radiation, thus minimizing or completely avoiding treatment induced side effects, such as nerve damage with resulting neurologic disfunction, as well as avoiding other complications such as breathing difficulties, nausea, impotence, secondary cancers and others.

Both standard X-rays/conventional radiation therapy and proton therapy attack tumors by preventing cancer cells from dividing and growing. The difference between the two therapies is that protons can precisely target the tumor, allowing patients to receive higher, more effective doses, and reducing damage to healthy tissue near the tumor. The chart below shows how protons eliminate radiation to the brain stem and X-rays do not.


When referencing the chart below, imagine that the Y axis (radiation dose) is the surface of a patient’s skin and the area between the dotted lines is is a tumor. The goal of treatment is to deliver the proper dose of radiation to the tumor while limiting the dose received by the surrounding healthy tissue. The sloping grey area shows how X-rays deliver a dose. To deposit the proper amount of energy into the tumor, X-rays must irradiate much of the healthy tissue in front of it, and they continue to penetrate through the tumor and irradiate much of the healthy tissue behind it. Protons deliver their dose in a very different way. As the orange area shows, they enter the patient at a low dose, then, at a precise depth, they deliver a large burst of energy. Immediately after this burst, they stop completely. To treat the entire tumor, additional protons are sent in at lower doses. In this way, protons completely irradiate the tumor while limiting the dose to the nearby healthy tissue. The areas shaded in grey show the additional dose delivered to healthy tissue by X-rays compared with protons. Proton treatment delivers a dose in a more accurate, more efficient way and spares more of the surrounding healthy tissue.


Although it is similar to conventional radiation therapy, protons are more precise, the proton beam is fine-tuned with millimeters of accuracy to deliver maximum energy within a controlled range of the tumor. Proton treatment can also be combined with radiation, chemotherapy and biological treatments, depending on the cancer type to provide better outcomes and less tissue damage. Also, Proton treatment greatly improves pediatric outcomes.

How it Works

When doses of protons (positively charged parts of an atom) enter a tumor, they deposit most of their energy at a specific target, destroying cancerous cells and preserving surrounding healthy tissue. This differs from conventional radiation therapy because a less significant dose of protons enter the body, therefore reducing damage to surrounding health tissue and critical organs. This results in a smaller chance for side effects and secondary cancers.

Provision Proton Therapy Center’s treatment rooms use pencil beam and uniform scanning, which further increases the precision of radiation, reducing overall treatment time and allowing the tumor to be directly targeted with aggressive doses of radiation.

How do I know if it’s for me?

A non-invasive treatment, proton therapy is best used to treat individuals with a localized tumor, in which the cancer has not spread to other parts of the body, and in situations in which tumors cannot be removed surgically. Proton therapy may be combined with other treatment options, depending on the specific details of your case.

To find out whether proton therapy is right for you, please contact us for more information on how to get started.