Carbon ion therapy for cervical cancer is used for cervical adenocarcinoma, which tends to respond less to conventional radiation, and for bulky squamous cell carcinoma of 6 cm or more. In Japan, carbon ion therapy for locally advanced cervical cancer has been covered by public health insurance since April 2022. At the 2025 ASTRO Annual Meeting, Gunma University Heavy Ion Medical Center reported a 4-year local control rate of 96% and a 4-year overall survival rate of 94% in 30 patients with locally advanced adenocarcinoma treated with carbon ions plus image-guided brachytherapy. To find out whether you are eligible and what the schedule and cost would be, send your records for a cervical cancer carbon ion therapy consultation.
Why is carbon ion therapy for cervical cancer drawing attention for adenocarcinoma?
Most cervical cancers are squamous cell carcinomas. Adenocarcinoma is less common, but it also occurs in younger women and its share is rising. For locally advanced cervical cancer (stage II and beyond) the standard treatment is radiation with cisplatin plus brachytherapy delivered from inside the uterus. Adenocarcinoma, however, tends to respond less to X-ray radiation at the same stage, so stronger treatments have been studied.
Carbon ion beams release most of their energy at a set depth (the Bragg peak), so a high dose can be given to the tumor while the rectum and bladder behind it receive less. Their biological effect is also greater than that of X-rays, so they can work even in radiation-resistant cancers. See What Is Carbon Ion Therapy? for the basics.
QST Hospital in Japan treated about 250 patients with cervical cancer using carbon ions between 1995 and 2018. Building on this experience, several Japanese centers refined the method together, and combining carbon ions with brachytherapy and chemotherapy is now well established.
What do the latest studies on cervical adenocarcinoma show?
Several human studies have been published in Japan in recent years. Patients, methods and follow-up differ, so the numbers cannot be compared directly, but the trend is clearly improving.
| Study | Patients / treatment | Main results |
|---|---|---|
| Japanese multi-institutional study (J-CROS), Cancers 2021 | 55 patients, stage IIB–IVA adenocarcinoma; carbon ions alone or with cisplatin, some with brachytherapy | 5-year overall survival 68.6%, 5-year local control 65.2%, no grade 4 toxicity |
| Japanese nationwide prospective registry (treated 2016–2020), IJROBP 2024 | 42 untreated patients, stage IIB–IVA adenocarcinoma, 4 centers | 2-year overall survival 97.5%, 2-year local control 80.9%, 2-year disease-free survival 64.3% |
| Gunma University Heavy Ion Medical Center, ASTRO 2025 | 30 patients, stage II–IVA adenocarcinoma; 16 carbon ion fractions + 3 image-guided brachytherapy sessions + weekly cisplatin | 4-year local control 96%, 4-year overall survival 94%, 4-year progression-free survival 66% |
In the most recent Gunma report, the median tumor diameter was 5.6 cm, yet the cervical tumor did not regrow over four years in almost all patients. The researchers called the combination of carbon ions and image-guided brachytherapy a promising option for locally advanced cervical adenocarcinoma and are running a trial adding an immune checkpoint inhibitor to further reduce distant recurrence.
In the 2021 multi-institutional study, patients whose tumors shrank well at 6 months had better local control and survival, so Japanese hospitals check response closely with regular MRI after treatment.
Side effects were mostly manageable. In the registry study, grade 3 rectal/sigmoid events occurred in 2 patients and a urinary event in 1; in the Gunma study, grade 3 or higher late events occurred in 2 patients (bladder bleeding, bowel obstruction). During treatment, diarrhea, frequent urination, fatigue and low white cell counts from chemotherapy can occur and are managed with medication and blood tests. See Carbon ion therapy side effects.
Who is eligible for carbon ion cancer treatment?
QST Hospital's English guide lists the following criteria for gynecological tumors. Basic information is also on our gynecologic cancer page.
| Condition | Criteria (QST Hospital English guide) | Records checked at consultation |
|---|---|---|
| Locally advanced cervical cancer | Stage II–IVA (FIGO 2008); adenocarcinoma of any size, squamous cell carcinoma 6 cm or larger | Pathology report, pelvic MRI |
| Endometrial cancer | Stage I–IVA that cannot be operated on because of complications or other reasons | Physician and gynecologist opinions |
| Gynecological melanoma | Localized melanoma of the vulva, vagina or uterus, including postoperative recurrence | Previous surgical records |
| Common conditions | No distant metastasis; no previous surgery or radiation for the same cancer | PET-CT or chest/abdominal CT |
Recurrence after radiation or surgery for cervical cancer generally falls outside these criteria, so the best time to consult is when you are first diagnosed and choosing a treatment. Stage I disease that can be treated surgically is usually not eligible either.
How long do treatment and the stay in Japan take?
QST Hospital's guide for patients from abroad lists about 5 weeks for uterine cancer. Depending on the hospital and patient, 20 carbon ion fractions (5 weeks) or 16 fractions plus 3 image-guided brachytherapy sessions (about 6 weeks) are used.
| Step | What happens | Expected time |
|---|---|---|
| 1. Record review | Records sent through a coordinator; the hospital decides eligibility | Before travel |
| 2. First visit / preparation | Examination, immobilization device, planning CT and MRI | A few days |
| 3. Treatment planning | Physicians design the beam plan (QST allows 1–2 weeks) | About 1–2 weeks |
| 4. Carbon ion irradiation | Once a day on weekdays, to the pelvic nodes and tumor | About 4–5 weeks |
| 5. Brachytherapy / chemotherapy | Depending on the hospital, 3 brachytherapy sessions and weekly cisplatin (based on age and organ function) | During/after irradiation |
| 6. After returning home | Regular MRI and visits with your local and Japanese hospitals | Several years |
With chemotherapy, blood tests are frequent and hospitalization may be recommended. Plan your companion's schedule and accommodation in advance. Compare contact points in 7 carbon ion therapy hospitals in Japan and see Japanese Institutions.
Carbon ion therapy cost and documents to prepare
Patients from abroad are not covered by Japanese public insurance and pay self-pay fees set by each hospital. QST Hospital lists carbon ion radiotherapy for patients from abroad at 5.786 million yen (tax included); other costs such as hospitalization, consultations and tests are charged at 33 yen per medical fee point, and coordinator fees are not included (QST Hospital guide for patients from abroad, accessed 21 October 2026). Brachytherapy and chemotherapy are charged separately. For total costs including stay and interpreting, see carbon ion therapy cost comparison.
Find out whether carbon ion therapy in Japan is possible for your stage and histology, and the expected total cost, through our consultation (+82-2-517-5117).
For cervical cancer, the following records speed up the eligibility review.
- Referral letter / medical summary: diagnosis, FIGO stage, treatment history (English translation required)
- Pathology report: histology such as adenocarcinoma or squamous cell carcinoma
- Imaging CD (DICOM): pelvic MRI within 1–2 months, PET-CT or chest/abdominal CT for metastasis
- Blood tests: kidney function (for chemotherapy decisions), hemoglobin
- Previous treatment: drug names, cycles and dates if you already had chemotherapy
- Current symptoms: bleeding, pain, urinary or bowel symptoms, medications
FAQ
Is carbon ion therapy for cervical cancer covered by insurance in Japan?
Since April 2022, carbon ion therapy for locally advanced cervical cancer has been covered by Japanese public insurance. Patients from abroad do not use Japanese insurance and pay the hospital's self-pay fee (QST Hospital: 5.786 million yen, tax included).
Can squamous cell carcinoma be treated with carbon ions?
Under QST Hospital's criteria, stage II–IVA squamous cell carcinoma of 6 cm or more is eligible. QST reports a 5-year local control rate of 70% for squamous cell tumors larger than 6 cm.
If I receive carbon ion therapy, do I still need chemotherapy?
Japanese hospitals now usually add weekly cisplatin when age and organ function allow. In QST data, adenocarcinoma patients who received cisplatin had a 2-year overall survival of 88%. Physicians decide based on blood tests and your condition.
What about pregnancy and ovarian function after treatment?
Pelvic radiation, including carbon ions, affects ovarian and uterine function. Menopausal symptoms can occur, and hormone management can be discussed at follow-up visits.
Related articles
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- Kumazawa T, et al. Carbon-ion radiotherapy with image-guided brachytherapy for locally advanced cervical adenocarcinoma. ASTRO 2025 Annual Meeting (Gunma University)
- Carbon-ion radiotherapy for adenocarcinoma of the uterine cervix: multicenter prospective registry-based study in Japan (2016–2020). Int J Radiat Oncol Biol Phys 2024
- Okonogi N, et al. Multi-institutional retrospective analysis of carbon-ion radiotherapy for locally advanced adenocarcinoma of the uterine cervix. Cancers 2021;13:2713
- QST Hospital — Gynecological tumors (indications for carbon ion radiotherapy)
- QST Hospital — Carbon ion radiotherapy for patients from abroad (fees and application)
- Kubo N, et al. Impact of COVID-19 pandemic on carbon-ion radiation therapy in Japan: national registry study. Int J Part Ther 2024;14:100634
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.