What is Proton Therapy?

Advanced Cancer Treatment Using Proton Radiation Treatment

Proton therapy is a type of radiation treatment that uses protons (subatomic particles) instead of X-rays to treat cancerous and non-cancerous conditions. It can target tumors with great precision, reducing damage to healthy nearby tissue and reducing the risk of secondary cancers caused by radiation exposure.

Benefits of proton therapy

  • Proton therapy is the most precise form of radiation treatment available today. The accuracy of protons enables doctors to treat tumors with a substantially lower total radiation dose to surrounding healthy tissue. Because proton therapy minimizes radiation exposure to healthy tissues, patients are better able to tolerate their treatments and are less likely to have treatment-related problems.
  • Protons stop where the tumor stops. Conventional X-ray treatment beams penetrate well beyond the tumor and can deliver unnecessary and potentially harmful radiation to surrounding tissues and structures. Protons can be controlled to conform precisely to the shape of the tumor and to release most of their energy within the tumor. The beam stops at the tumor’s edge, which helps preserve normal tissue.
  • Proton therapy may allow you to receive higher, more effective doses of radiation. Since proton therapy does not penetrate surrounding tissues, you may be able to receive a higher dose directly to the tumor which often allows for the shortening of your overall treatment period.
  • Scientific research has shown that proton beam therapy is as effective as conventional X-ray radiotherapy but causes less toxicity to vital organs and a reduced rate of secondary cancers. As we get better at curing cancer and people are living longer after treatment, there is cause for concern about long-term side effects. A 2016 study in The Lancet Oncology found that proton therapy has similar cure rates with fewer side effects and long-term toxicity than X-ray radiation.
  • Studies published in peer-reviewed medical journals have demonstrated the safety and effectiveness of proton therapy for a broad range of tumor sites. Proton therapy is best suited for solid tumors that are localized (i.e., have not spread), located near sensitive heathy tissue, and require high doses of radiation. Proton therapy can treat these tumors in a number of ways:
  • In combination with chemotherapy
  • Preoperatively (often with chemotherapy) in an attempt to shrink tumors to make surgery more feasible

Read more about the conditions that can be treated by proton therapy.

  • Proton is recognized as the preferred form of radiation therapy for many pediatric cancers. Because children’s bodies are still growing, they are extremely sensitive to the harmful effects of radiation. Proton therapy precisely targets the tumor while minimizing radiation to healthy, developing tissue and organs.

Is proton therapy a new cancer treatment?

Carl Rossi, MD, medical director of Scripps Proton Therapy Center in San Diego, explains the history of proton therapy.

Advanced imaging devices in one location

Scripps Proton Therapy Center not only offers the latest generation of technology in particle beam radiation therapy; it has the most advanced imaging devices available and is the first center in the nation to place those tools within the treatment location itself. This results in greater convenience for the patient because it allows the medical team to perform all treatment planning at one site.

Learn more by reviewing a glossary of terms related to proton therapy.