May 23, 2026
Heavy particle therapy — including next-generation proton beam therapy and carbon ion therapy — has the potential to transform treatment paradigms not only for rare, radioresistant cancers but also for more-common malignancies. These therapies, which will be offered in the Americas for the first time at the Mayo Clinic Comprehensive Cancer Center in Jacksonville, Florida, give patients with cancer a precision approach that allows for more-effective treatments and fewer side effects.
Laura A. Vallow, M.D., a radiation oncologist and chair of Radiation Oncology at Mayo Clinic in Florida, has been leading efforts to implement proton beam and carbon ion therapies alongside existing photon therapies for patients at Mayo Clinic. These advanced care options bring hope to patients with the most aggressive and historically treatment-resistant cancers.
"Heavy particle therapy with protons and carbon ion technology will offer patients the maximum amount of enhanced cancer-fighting benefits the technologies provide," Dr. Vallow says. "Those benefits include potential reduction in secondary cancer development, as well as improved treatment for near spinal cord tumors, adenoid cystic carcinoma, pelvic sarcoma, pediatric cancers and other forms of cancer."
A new duo of powerful heavy particles
Mayo Clinic will be the first in the Americas to provide these advanced treatments to patients. With photon therapy already offered, advanced proton beam therapy will be available in early 2027 and carbon ion therapy in early 2028. These radiation approaches, which can be personalized for each patient and type of cancer, could improve outcomes while reducing long-term effects.
Through collaboration with a global technology and engineering company headquartered in Japan and other partners, Mayo Clinic will provide treatment capabilities, including photon, proton and carbon ion therapy, that are available nowhere else in the world. These treatments offer faster, more accurate treatments with adaptive planning. All these therapies are effective for certain patients and types of cancers, and having multiple options available gives physicians more resources to address hard-to-treat cancers.
Photon therapy, which relies on high-energy X-rays, is effective for treating certain types of cancer. At Mayo Clinic, advanced capabilities limit damage to healthy tissues while focusing the maximum effective dose on the tumor — including with prone positioning and hypofractionation.
Proton treatments offer lower toxicity and potentially fewer secondary malignancies later in patients' lives. As a result, proton therapy is an ideal treatment option for pediatric tumors. Mayo Clinic in Jacksonville, Florida, will offer a special form of proton therapy called pencil beam scanning, which delivers higher doses of radiation to cancer cells while sparing healthy tissues. For the past several years, Mayo Clinic Medical Physics has worked closely with Hitachi to ensure the proton technology is best in class and can deliver next-generation particle therapy treatment.
Carbon ion therapy is a highly effective, unique tool for treating cancer. Carbon ions have a greater mass and energy than protons do and are effective at killing certain cancer cells, particularly those in historically radioresistant tumors. Carbon ions deliver a higher linear energy transfer, leading to potentially lower dosages and fewer treatments for efficacy. Carbon ion therapy may also be able to harness a patient's own immune system to fight cancer.
The latest technology, a more targeted approach
Advanced 360-degree proton gantries and carbon fixed beam enable enhanced targeting of hard-to-treat cancers. These technologies help Mayo Clinic physicians conduct integrated therapy planning and simulation in conjunction with radiation oncology treatments.
Other diagnostic and treatment modalities available in the Duan Family Building at Mayo Clinic in Jacksonville, Florida, include:
- An upright chair positioning system, which is the first of its kind in photon treatment.
- Multi-ion fixed beam room (commissioned with carbon in early 2028).
- Synchrotron accelerator that can switch between three heavy particle energies in less than 20 seconds.
- 3T MRI system.
- Photon linear accelerators for radiation therapy.
To enhance the benefits of heavy particle therapy delivery, Mayo Clinic is partnering with a software development company to create an advanced treatment planning system that works with photon, proton and carbon ion therapies. This system, which is not typically available for most patients receiving radiation therapy, reduces the radiation dose sent to healthy tissue. It also provides real-time online adaptive treatment planning — adjusting each patient's plan daily based on tumor shrinkage or shifting.
"The system offers online adaptive planning that uses daily patient imaging," Dr. Vallow says. "This information is correlated based on the contours and prior scans, and then each patient's individual treatment plan is reoptimized to precisely target the tumor as treatment progresses."
Expanding therapy options for cancer treatment
Mayo Clinic is exploring new directions for proton and carbon ion therapy research, including continued evaluation of the physics of heavy particle treatment modalities and how carbon ion therapy stimulates the immune system in ways that other particle therapies do not.
Research also is underway to expand knowledge about patient selection, such as which patients would benefit most from proton therapy, carbon ion therapy or a dual carbon-proton approach. Part of this research involves evaluation of the impact of these therapies on common cancers compared with rare cancers, and which patients with common cancers would benefit from carbon ion as a first line treatment.
"By launching these remarkable therapies, Mayo Clinic continues to innovate in clinical care and research," Dr. Vallow says. "We remain focused on delivering better patient outcomes and bringing hope to all people facing a cancer diagnosis."
For more information
Refer a patient to Mayo Clinic.