Carbon Ion Therapy vs Surgery for Liver Cancer: 2025 Japan Results

Many patients ask whether carbon ion therapy instead of liver cancer surgery is a reasonable choice. Three Japanese studies published in 2025 help answer that question. In a multicenter analysis of 1,063 patients with hepatocellular carcinoma (HCC), people treated with a carbon ion therapy machine and people who had liver resection had similar recurrence-free survival (Hepatology Communications, 2025). This article summarizes the three studies, who is eligible, the schedule, and costs for international patients. To find out whether your test results could be reviewed for carbon ion cancer treatment, please use our eligibility and cost consultation.

How does a carbon ion therapy machine treat liver cancer?

A carbon ion therapy machine accelerates carbon nuclei to near the speed of light and aims them at the tumor. Carbon ion beams release most of their energy at a set depth and then stop (the Bragg peak). The tumor receives a strong dose while the normal liver and bowel behind it receive little. This matters in the liver, where recovery depends on how much healthy tissue remains.

QST Hospital in Chiba, Japan, has treated HCC with carbon ions since the 1990s. Early trials shortened the course from 15 sessions to 4 and even 2, and 4 sessions is now a standard schedule. According to QST Hospital's English page, 133 patients treated from 1997 to 2001 had a 3-year local control rate of 90.3%, with no grade 4 or higher toxicity and no treatment-related deaths. See What is carbon ion therapy? for how the machine works.

Since April 2022, carbon ion therapy for HCC 4 cm or larger has been covered by Japan's public health insurance, which reflects the evidence behind it. International patients without Japanese insurance are treated on a self-pay basis.

Multicenter study: 947 surgery vs 116 carbon ion patients

The largest study appeared in Hepatology Communications in 2025. Among patients treated for early HCC in Japan from 2010 to 2022, 116 received carbon ion therapy and 947 had liver resection. Because the groups differed in age and liver function, the researchers balanced them statistically (inverse probability of treatment weighting, IPTW).

Unadjusted survival looked slightly better with surgery, but the gap disappeared after balancing. The authors explained that younger and fitter patients tended to receive surgery. They concluded that carbon ion therapy may achieve outcomes comparable to surgery in well-selected patients with early HCC.

Can resectable liver cancer be treated with carbon ions?

Kanagawa Cancer Center studied patients judged resectable who chose carbon ion therapy themselves (JGH Open, 2025). Among patients with a single, newly diagnosed HCC without major vessel invasion, 23 received carbon ion therapy and 41 had resection. Carbon ion therapy was 60 Gy(RBE) in 4 or 12 sessions, all as outpatients.

Local control after carbon ion therapy was 77.0% at both 3 and 5 years. There were no grade 4 events, and the most common effect was mild skin redness (22%). The authors concluded the treatment was safe and may give results comparable to resection.

Liver cancer over 4 cm: results of a 4-day course

Yamagata University studied HCC 4 cm or larger, the size covered by Japanese insurance (Journal of Clinical Medicine, 2025). Thirty-eight patients received carbon ion therapy and 13 had resection. Carbon ion therapy was 60 Gy(RBE) once daily on 4 consecutive days, and all 38 completed it.

Overall survival with carbon ions was 97.4% at 1 year and 94.7% at 2 years, not significantly different from resection (100%). In patients under 80, 2-year local control was 92.3%. Side effects were mostly grade 1 or 2 liver enzyme changes, fatigue and skin redness. One patient had a grade 3 bile duct narrowing that was treated with an endoscopic stent. The authors concluded carbon ion therapy may be as effective as resection in patients under 80.

For tumors over 10 cm, see carbon ion therapy for large liver cancer.

Who is suitable, schedule and cost

QST Hospital describes good candidates as patients whose cancer is confined to the liver, usually with 3 or fewer lesions, when surgery or radiofrequency ablation is difficult due to location, liver function or other illness. Tumors very close to the bowel may be better treated another way. All three studies included patients with Child-Pugh A or B liver function. Criteria are summarized on our liver cancer eligibility page.

International patients first have a record review, an initial visit, a fixation device and a planning CT, then start treatment 1–2 weeks later. Compare hospitals in carbon ion therapy cost and our Japanese institutions guide.

Whether surgery or carbon ion therapy fits you depends on tumor location and liver function. Send us your records via contact or call +82-2-517-5117, and we will explain which hospitals could review your case and how to prepare.

Documents to prepare

• Referral letter: diagnosis, tumor size and number, past treatment (embolization, ablation, surgery)
• Contrast CT or MRI from the last 1–2 months (DICOM on CD)
• Liver blood tests (albumin, bilirubin, platelets, prothrombin time) and tumor markers (AFP, PIVKA-II)
• Hepatitis virus test results and medication list
• Your surgeon's opinion on resectability, if available

See documents checklist for tips.

FAQ

Are results similar if I choose carbon ion therapy instead of liver surgery?

In a Japanese multicenter study (1,063 patients) and the Kanagawa and Yamagata studies, well-selected HCC patients had statistically similar recurrence and survival with carbon ions and surgery. Japanese doctors decide based on tumor location, liver function and age.

How long does carbon ion cancer treatment for the liver take?

Often 4 sessions on 4 consecutive days. Tumors near the bowel may need 12 sessions over about 3 weeks; QST Hospital lists 2 days to 3 weeks.

How common are side effects?

Mostly mild skin redness, fatigue and liver test changes. Grade 3 or higher events were around 4% and were managed with procedures such as endoscopy.

Can older patients receive it?

No general anesthesia or incision is needed, so older patients can be considered. Results were especially good under age 80; for those 80 and over, doctors compare options.

What does it cost for international patients?

QST Hospital charges 5.786 million yen (tax incl.) plus hospital and test fees; Osaka HIMAK charges foreign self-pay patients 4.8 million yen plus tax (checked 28 Oct 2026). Travel, stay and interpreting are extra.

Sources

• Hepatology Communications (2025) — Carbon-ion radiotherapy achieves outcomes equivalent to surgical resection for HCC
• JGH Open (2025) — CIRT vs surgical resection for solitary, potentially resectable HCC (Kanagawa Cancer Center)
• Journal of Clinical Medicine (2025) — CIRT vs hepatectomy for HCC ≥4 cm (Yamagata University)
• QST Hospital — Liver cancer indications
• QST Hospital — For patients from abroad (fees)
• Osaka Heavy Ion Therapy Center — Treatment fees

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.