MR-Guided Radiotherapy for Pancreatic Cancer vs Carbon Ion in Japan

MR-guided radiotherapy for pancreatic cancer uses MRI on the treatment table to see the day's tumor, stomach and duodenum positions, adjusts the plan on the spot, and is usually completed in about 5 sessions. In a phase 2 trial at 13 centers in the United States, Italy and Israel, 136 patients with locally advanced or borderline resectable pancreatic cancer had a 2-year survival from diagnosis of 53.6% (Radiotherapy and Oncology, 2024). Several Japanese university hospitals use this equipment (MR-Linac), making it an option worth comparing with carbon ion therapy. This guide covers how it works, who is eligible, hospitals in Japan, costs and the difference from carbon ion therapy. To ask which option may suit your case, use our pancreatic cancer radiotherapy eligibility and cost consultation.

What makes MR-guided radiotherapy different?

An MR-Linac combines a linear accelerator (Linac), which delivers radiation, with an MRI scanner in one machine. Conventional machines align the patient with CT before treatment, but CT shows the borders between the pancreas and nearby organs poorly. MRI shows soft tissue clearly, so the team can check at every session how close the stomach, duodenum and small bowel are to the tumor.

The key feature is on-table adaptive planning. Organs shift a little every day with breathing and digestion. With MR-guided radiotherapy, an MRI is taken while the patient lies on the table, and the dose distribution is recalculated for that day's bowel position. Japan's National Cancer Center Hospital states that this re-planning takes about 20 minutes. During treatment the tumor is followed on MRI, and the beam pauses automatically if the tumor moves outside the set margin.

Sparing normal organs this way allows a higher dose to the tumor. According to the same hospital, pancreatic cancer radiotherapy usually needs 28 sessions, but with this machine the course can be shortened to about 5 sessions while raising the tumor dose. The basics of radiotherapy are explained in What is carbon ion therapy?

Phase 2 trial results in 136 pancreatic cancer patients

The most cited evidence is the SMART trial. Thirteen centers in three countries, including Miami Cancer Institute in the United States, treated 136 patients with borderline resectable or locally advanced pancreatic cancer between January 2019 and January 2022. All patients had first received at least 3 months of chemotherapy without distant spread, then received a total of 50 Gy in 5 MR-guided sessions. The results were published in Radiotherapy and Oncology in 2024.

The investigators concluded that 5-session high-dose MR-guided treatment was safe with favorable long-term survival, and proposed a phase 3 trial against chemotherapy alone for locally advanced disease. The main significance is that severe effects such as bleeding or perforation were uncommon despite the high dose.

Which pancreatic cancer patients are eligible?

MR-guided radiotherapy is mainly considered in the following situations. Final eligibility is decided by the Japanese medical team after reviewing images and chemotherapy response.

• Locally advanced or borderline resectable pancreatic cancer without distant metastasis
• No distant spread after at least 3 months of chemotherapy
• Surgery judged difficult because the tumor surrounds major blood vessels
• Able to undergo MRI (check for implanted metal or a pacemaker in advance)
• Able to follow breath-hold instructions on the treatment table

Besides localized pancreatic cancer, National Cancer Center Hospital listed localized prostate cancer, lung, liver and kidney cancers up to 5 cm without metastasis, and isolated lung or liver metastases as main indications. Japanese health insurance recognizes this treatment as stereotactic radiotherapy.

Which hospitals in Japan use an MR-Linac?

According to a newsletter of the Japanese Society for Radiation Oncology (JASTRO), five MR-Linacs were operating in Japan as of September 2022, and the number has been growing gradually. The hospitals below are confirmed by official announcements.

Acceptance of international patients and waiting times differ by hospital. Japanese carbon ion facilities are listed in Treatment institutions in Japan, and we can help you decide which hospital to contact first.

Versus carbon ion therapy: sessions, duration and cost

Both treatments aim to give a high dose to inoperable pancreatic tumors while sparing nearby organs. The difference lies in how normal tissue is protected. Carbon ion therapy relies on the physical property of carbon ions stopping at a set depth (the Bragg peak). MR-guided radiotherapy uses X-rays but protects organs by checking bowel position on MRI and re-planning every session.

Japan's medical fee schedule (FY2026 revision) sets one course of stereotactic radiotherapy at 63,000 points. For patients with Japanese insurance, one point is 10 yen, or JPY 630,000, to which the co-payment rate applies. International patients without Japanese insurance are charged at a self-pay rate set by each hospital. For example, Gunma University Hospital announced that from 1 December 2025 it charges 30 yen per point to foreign nationals without Japanese public insurance. At that rate, the basic treatment points alone would be JPY 1.89 million. Planning, MRI, consultations, chemotherapy and accommodation are extra.

For carbon ion therapy, QST Hospital lists JPY 5.786 million (tax included) for international patients, and Osaka Heavy Ion Therapy Center lists JPY 4.8 million plus consumption tax for self-pay foreign patients (checked 28 October 2026). See carbon ion therapy costs in Japan and our pancreatic cancer carbon ion therapy guide.

Which treatment suits you depends on the distance between the tumor and the duodenum, the extent of vessel involvement, and the response to chemotherapy. To review both options, please use our consultation form or call +82-2-517-5117.

Records to prepare before a consultation

• Doctor's letter with diagnosis, stage and date of diagnosis
• Original contrast CT and MRI images from the last 1–2 months (DICOM on CD)
• Pathology report from the biopsy
• Chemotherapy drug names, number of cycles and changes in tumor size
• Tumor marker (CA19-9) trend and recent blood tests
• Whether you have a biliary stent, pacemaker or other implanted metal

Tips for each document are in documents for carbon ion therapy. Most Japanese hospitals ask for the same records.

Frequently asked questions

How many sessions and days does MR-guided radiotherapy take?

Pancreatic cancer is usually treated in 5 sessions, typically finished within 1–2 weeks. Each session takes longer than standard radiotherapy because of MRI imaging and re-planning.

What are the results of MR-guided radiotherapy for pancreatic cancer?

In a 13-center phase 2 trial, 2-year survival from diagnosis among 136 patients was 53.6%, and no grade 3 or higher GI side effects were definitely related to treatment.

Which is better, carbon ion or MR-guided radiotherapy?

No trial has compared them directly yet. Carbon ion therapy spares organs with the Bragg peak, and MR-guided treatment with daily re-planning. The choice is made with the medical team considering tumor location, duration and cost.

Can international patients receive it in Japan?

Some hospitals accept self-pay patients through their international patient desks. Eligibility is first checked using images and a doctor's letter.

Can I receive it if I have metal in my body?

Because MRI is taken every session, a pacemaker or certain metal devices may make it difficult. The device type and MRI compatibility are checked first.

Sources

• Chuong MD et al. SMART for borderline resectable and locally advanced pancreatic cancer: multi-center phase 2 study. Radiotherapy and Oncology 2024
• National Cancer Center Hospital (Japan): MRIdian radiotherapy (Japanese)
• JASTRO Newsletter No.146 special feature on MR-Linac (Japanese)
• Tohoku University Hospital: Elekta Unity press release (Japanese)
• ViewRay: Edogawa Hospital adopts MRIdian Linac (2021)
• Japan medical fee schedule M001-3 linear accelerator radiotherapy, FY2026 (Japanese)
• Gunma University Hospital: revised fee per point for foreign patients, effective 1 Dec 2025 (Japanese)
• QST Hospital — For patients from abroad
• Osaka Heavy Ion Therapy Center: treatment fees (Japanese)

General information based on public sources; not a substitute for diagnosis or treatment. Eligibility is decided by the treating physicians. Written by the FTH editorial team.