A case of hepatocellular carcinoma initially treated by carbon ions, followed by protons for marginal recurrence with portal thrombus.

We report a case of hepatocellular carcinoma (HCC), initially treated by carbon ions, then subsequently by protons for marginal recurrence. A 52-year-old man with stage II HCC was enrolled in the clinical study for carbon ion therapy. A total dose of 52.5 GyE in 8 fractions was delivered through a right lateral port for 13 days. Dynamic CT performed 7 months after the initiation of carbon ion therapy showed a decrease in the size of the tumor. Dynamic CT performed 12 months after the therapy revealed marginal recurrence of HCC accompanied with portal vein tumor thrombus (PVTT). Proton therapy of 66 GyE in 22 fractions was delivered through posterior and right lateral ports for 33 days. Dynamic CT performed 3 months after the initiation of proton therapy showed a regression of the recurrent tumor and disappearance of the PVTT. No serious adverse effects were observed during or after these two treatments. He was free from further recurrence 27 months after the initiation of the first carbon ion therapy. Both carbon ions and protons were effective with minimal side effects.