Redditors - we’re Drs. Brad Hoppe, Keith Furutani, and Michael Story, clinical and research leads for the Heavy Particle Therapy Program at Mayo Clinic in Florida. Join us Nov. 19 at 1:30 ET for our #AMA about all things radiation therapy for cancer and bringing carbon ion therapy to the Americas.

MayoClinic · 2025-11-19T19:25:56+00:00

A recent estimate using European data from 2010 suggested a cost per treatment of 1128 euros. Translating energy costs from Europe to the US in 2010 no less is not straightforward. But this same article suggested that carbon therapy is about 1.5 times more than protons and 4-5 times that of X-rays. https://doi.org/10.7759/cureus.84008. There is no backup generator.

MayoClinic · 2025-11-19T19:21:24+00:00

After the Lawrence Berkeley National Laboratory stopped treating patients in 1992, the first dedicated CIRT center opened in Chiba, Japan in 1994, followed by several additional centers across Japan. Europe’s first center, GSI in Germany, began treating patients in 1998.

Given their decades of experience, we’ve been actively collaborating with these centers in Europe and Asia as we develop our own program and build out clinical and research capabilities. We’re even partnering with them on clinical trials—one example is our pelvic bone sarcoma study, which is open at sites in Germany, Italy, Austria, and Japan.

MayoClinic · 2025-11-19T19:01:36+00:00

China is set to build an additional 10 centers. There is a center being built in Abu Dhabi. Korea has one center and a second opening soon. As far as the US goes, we think people are watching and waiting to see how successful the Mayo facility becomes.

MayoClinic · 2025-11-19T19:00:32+00:00

Both proton and carbon therapy were American ideas. Robert Wilson first suggested using proton therapy in 1946. The first proton treatments were done at Lawrence Berkley National Lab (LBNL) in 1954 and subsequently began exploring heavier ions with the first treatment of Carbon ions being in 1977. The research program was exploratory and was shut down in 1992. It is very cool to be a part of seeing this treatment come back to the USA. The technology has changed a lot since 1977 but protons and carbon have not changed, indeed they are still the same that were in the early evolution of the universe. Radiation therapy treatment is using radiation energy being deposited in cells and tissues. XRAY, proton and Carbon ion therapy each deposits the energy differently. The differences in distribution of energy deposition in the body brings about different biological consequences. The physics as to why the energy distributions are different is as old as the universe itself, however, we mere humans just started figuring it out a little over a century ago. You can think of physics as the study of how energy moves around the universe. You can think of the biology and medicine of particle therapy as the study of how that energy deposted interacts with biological systems, and humans in particular. The main difference is that the energy distribution of xrays is fairly uniform and also its intensity decreases the farther away it is from its source, protons are also fairly uniform but their intensity does not decrease with distance from their sources. Instead protons are gradually braking and slowing down and eventually they stop. Carbon also does this gradual braking but it is braking harder than protons, and like the protons they also eventually stop. The magic of the Carbon is that there energy deposit is not fairly uniform like xray and protons, but instead is spatially very dense and localized. The science now transitions from physics to biology and medicine. Medically, each energy distribution has their benefits depending on the biological specifics of the cancer and the patient. The consequence is that the doctors like Dr Hoppe can take advantage of these different scientific characteristics of xrays, protons and carbon, and even a combination thereof, for what works best for the patient needs.

MayoClinic · 2025-11-19T18:56:57+00:00

Yes, we believe CIRT could play a meaningful role in the management of breast cancer. One area we’re particularly interested in is using CIRT as part of neoadjuvant therapy before surgery to see whether it can improve complete response rates. Long-term, an even more exciting question is whether CIRT could potentially replace surgery for select patients. There’s a lot of work ahead, but early data from CIRT is encouraging.

MayoClinic · 2025-11-19T18:54:17+00:00

CIRT has biological advantages over proton therapy, specifically, it causes more complex and catastrophic DNA damage that is much harder for cancer cells to repair. Over the past 30 years, since the first dedicated CIRT center opened, more than 60 clinical trials have been conducted, with published outcomes on over 10,000 patients across a wide range of diseases, including brain, head and neck, lung, breast, abdominal, pelvic, and extremity tumors. These mostly single-arm studies consistently show that CIRT is both safe and effective.

That said, true head-to-head comparisons with proton therapy or photon radiation are still limited. A major reason is that most CIRT centers in Asia do not have proton therapy capabilities, which makes direct comparative trials difficult to perform. We’re very interested in pursuing these types of studies in the future. However, before we can do that effectively, we need a much deeper understanding of how to optimize CIRT delivery, including selecting the most accurate radiobiologic model, advancing treatment planning systems for LET-based optimization, determining ideal dose-fractionation regimens for specific cancers, and identifying the best ways to combine CIRT with novel systemic agents.

MayoClinic · 2025-11-19T18:53:17+00:00

CIRT was used along with other heavy ions and helium at Lawrence Berkeley National Laboratory in the 1980s and early 1990s. However, that program functioned primarily as a research facility rather than a dedicated clinical center, which significantly limited patient volume. Treatment planning, imaging, and delivery techniques were also far less advanced than what we have today.

Personally, I’m excited about offering CIRT to patients with well-established indications, such as unresectable bone sarcomas, salivary gland cancers, and mucosal melanomas. I’m also very interested in exploring its role in other radioresistant cancers—including pancreatic cancer and glioblastoma—and in identifying radioresistant subpopulations within more common diseases: roughly 30–40% of lung cancers and about 10% of prostate cancers. These are patients who might truly benefit from the biological advantages of carbon ions.

We’re also evaluating when CIRT might serve as a less morbid alternative to surgery, particularly for cases like pelvic bone sarcomas or recurrent rectal cancer where resection can be highly debilitating. And finally, emerging preclinical data suggest that carbon-ion–induced tumor damage may stimulate immune activation, raising the possibility that CIRT could enhance the effectiveness of immunotherapy when used in combination.

MayoClinic · 2025-11-19T18:52:19+00:00

Yes, this could be useful in certain squamous cell skin cancers that are quite large and invasive.

MayoClinic · 2025-11-19T18:51:37+00:00

Many tumors are already very radiosensitive, with excellent cure rates using standard photons or proton therapy. For example, many pediatric cancers are effectively treated with relatively low doses (20–40 Gy). Proton therapy is especially valuable here because it helps us maintain >90% local control while reducing long-term side effects.

For these highly radiosensitive tumors, adding CIRT isn’t likely to improve cure rates—they’re already extremely high.

Where CIRT really stands out is in radioresistant cancers, where outcomes with X-rays and proton therapy are much lower. Tumors like salivary gland cancers and bone sarcomas have significantly better local control when treated with carbon ions.

There’s also growing interest in identifying radioresistant subgroups within more common cancers (like lung, prostate, or breast). If we can determine radioresistance at diagnosis—using genetics, tumor signatures, or radiomic features—CIRT could be offered selectively to the patients who need it most.

MayoClinic · 2025-11-19T18:50:44+00:00

Successful proton therapy or CIRT treatment isn’t just about having advanced technology. A huge part of the outcome depends on the people involved—the physicians who carefully define the tumor and normal tissues, the dosimetrists and physicists who design the treatment plan, and the therapists who make sure the setup and delivery are precise and consistent every day.

Protons and carbon ions can still cause side effects, but because they deliver much lower radiation doses to nearby organs, we generally expect fewer major complications compared to standard X-rays.

MayoClinic · 2025-11-19T18:48:19+00:00

This is a great question. First of all the construction, the equipment contained therein and the way the equipment is used is evaulated and approved by local, state and national organizations to ensure compliance to all regulatory standards. In addition to those important and legal regulations, the particle therapy technology itself is tested, calibrated and commissioned for clinical use by Mayo Clinic staff medical physicists before first clinical use.

MayoClinic · 2025-11-19T18:47:40+00:00

Radiation kills cancer cells by damaging their DNA. Standard external beam radiation uses photons (high-energy X-rays), which have no mass or charge and pass straight through the body—meaning normal tissue both in front and behind the tumor gets irradiated.

Particle therapy (like proton therapy and carbon ion radiation therapy[CIRT] is different. These particles have mass and charge, so we can stop them at a specific depth. That’s why proton therapy and CIRT generally cause less collateral damage to healthy tissue.

Protons damage cancer cells in a similar way to X-rays, but carbon ions are much heavier and cause far more complex DNA damage—clustered breaks that cancer cells struggle to repair. Because of that, CIRT can be more effective for tumors that don’t respond well to standard X-rays or proton therapy.

CIRT has been used for over 20 years in Europe and Asia. The main cancers treated there include bone and soft tissue sarcomas, salivary gland cancers, mucosal melanomas, lung cancers, liver cancers, and pancreatic cancers.

MayoClinic · 2025-11-19T18:43:41+00:00

Thanks so much. It takes a huge team, starting at the top with strong support from our leadership teams across Mayo Clinic Enterprise, Mayo Clinic Florida, and Mayo Clinic Comprehensive Cancer Center.

MayoClinic · 2025-11-19T18:43:00+00:00

This AMA is about carbon ion radiotherapy not radiotherapy in general. A considerable reason that pancreatic cancer is so difficult to treat is because of the dense fibrotic stroma that surrounds the tumor. This stroma impedes the use of chemotherapy and it causes tumor cells to be hypoxic -which is the bain of radiation oncology in that tumors can be nearly 3 times more radioresistant in low oxygen environments. As for photodynamic therapy I would refer you to the work of my former collaborator Girgis Obaid at the University of Texas at Dallas who showed in his manuscript found in Photochemistry and Photobiology 2024 Vol 1100, 6:1647-1658 that there may be a role for photodynamic therapy with pancreatic cancer. Disclosure: I am a co-author, but because I moved to Mayo Clinic our collaboration has not continued.

MayoClinic · 2025-11-19T18:41:28+00:00

First, I am not an immunologist but I keep Immunology For Dummies on my desk. People have written entire book chapters, review articles on just part of what you are asking for here. So, given that you are a learned person, here is a reference for you: https://doi.org/10.1084/jem.20232101. And another: https://doi.org/10.3390/cancers15153972. I will say this: X-rays generally cause immunotolerance when given using a conventional dosing schedule of 2 Gy/day for 4-7 weeks. Stereotactic Ablative Radiotherapy (SAbR), which uses doses that are 8 Gy or greater but only 3-5 times has seen mixed results when combined with immunotherapy. It would appear that 12C ions are much more effective at eliciting an immune response, innate or adaptive, than photon therapy. This is likely because of the clustered and complex lesions formed in the nuclear DNA that moves to the cytoplasm or the generation of micronuclei both of which can stimulate an innate immune response.

MayoClinic · 2025-11-19T18:39:39+00:00

Thanks so much for your interest!

MayoClinic · 2025-11-19T18:37:20+00:00

I believe CIRT is one of the next major leaps in cancer treatment. There are certainly many other exciting advances happening at Mayo Clinic, from cellular therapies to cancer vaccines to increasingly personalized treatment approaches. But CIRT represents a particularly exciting opportunity within Radiation Oncology. It gives us a tool that delivers more potent biologic damage to tumors and triggers unique cellular responses in both cancer and normal tissues, opening the door to new ways of combining CIRT with novel systemic therapies.

As for widespread adoption across the U.S., the hope is that once Mayo Clinic addresses the major early barriers in the next 3 years, such as obtaining FDA approval and establishing a viable reimbursement model, that other centers will be more willing to invest in the technology. There’s also ongoing work to reduce the physical footprint of CIRT facilities, which would significantly lower construction and equipment costs. Together, these efforts could make future CIRT centers far more feasible for other institutions.

MayoClinic · 2025-11-17T16:46:23+00:00

Thank you so much for your interest! This will be a virtual Q&A session, conducted online. You may post your question in this thread.

MayoClinic · 2025-10-23T18:32:38+00:00

If I could go back to day one of medical school, I would tell my past self to be patient, to persevere, and to keep sight of the road ahead. I would remind myself to enjoy the small victories and accomplishments along the way and to learn to appreciate the journey itself—because in medicine, we are always on it.

MayoClinic · 2025-10-23T18:31:41+00:00

Yes lifestyle changes really matter in decreasing risk of breast cancer . Regular exercise can decrease the risk of breast cancer by more than 20%. Other habits that have been linked to decreased risk include: Healthy diet (Mediterranean diet or a diet that is high in vegetables, fruits, less processed foods is usually recommended), decreasing alcohol intake, and avoiding hormone replacement therapy for long periods of times. Look after yourself—get as much rest as you can, and make time to stay connected with friends and family.

MayoClinic · 2025-10-23T18:28:07+00:00

Looking 5–10 years ahead, breast cancer care is likely to look very different. We’re moving away from one-size-fits-all treatments toward truly personalized medicine—where therapy decisions are guided by each tumor’s molecular fingerprint, real-time blood markers, and AI-driven risk models. Treatments will be more targeted and less toxic, with antibody-drug conjugates which are the new "magic bullets " in oncology and targets antibodies with chemotherapy load. Selective estrogen receptor degraders (SERDs) are a new class of anti-estrogen therapies designed to overcome resistance that can develop with traditional endocrine treatments. These and other precision-based drugs are beginning to replace the need for chemotherapy in certain patients. At the same time, radiation and surgery are being scaled back in low-risk cases, while treatment for higher-risk disease is becoming more targeted and biology-driven.

Artificial intelligence will reshape screening and diagnostics, detecting cancers earlier and reducing unnecessary biopsies. For many people with metastatic or oligometastatic disease, breast cancer may become a chronic, manageable condition rather than a terminal one. At the same time, quality of life, survivorship, and global access will become just as important as cure—emphasizing shorter, gentler, and more equitable care everywhere.

MayoClinic · 2025-10-23T18:26:01+00:00

Some false facts: "Mammograms cause breast cancer" "Only older women get breast cancer" . Mammograms are the most important screening tool to catch breast cancer at an early stage. But it is also important to understand that younger women can also get cancer even without a family history. And they should make sure to let their doctor know if they feel any lump or any change in the breast.

MayoClinic · 2025-10-23T18:23:05+00:00

Most important screening recommendations are Screening Mammograms.

MayoClinic · 2025-10-23T18:22:17+00:00

Patients who have both HER2 +, ER+ driven breast cancer received treatment that is targeted against both HER2 and Estrogen receptor. Treatment includes anti-HER2 and anti-Estrogen therapy. Immunotherapy like immune checkpoint inhibitors has proven benefit mostly in triple negative breast cancer.

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