Proton Beam Therapy for Hepatocellular Carcinoma after the Fontan Procedure

Background: Hepatocellular carcinoma (HCC) is more likely to occur in patients with a history of Fontan surgery, possibly due to long-term liver congestion. Proton beam therapy (PBT) may be effective for HCC that develops after Fontan surgery. Methods: Six lesions in 5 patients (3 females, 2 males) received PBT. The median age of the patients was 33 (range 21 - 42) years, and the median age at the time of the Fontan procedure was 6 (5 - 13) years. Four patients had multiple HCC at the time of PBT. The median tumor size was 57 (22 - 80) mm and 4 patients were classified as Child-Pugh B. Two patients received transcatheter arterial chemoembolization before PBT. The schedule of PBT was 66 Gy (RBE) in 10 fractions for 2 lesions, 72.6 Gy (RBE) in 22 fractions for 2 lesions, and 74 GyE (RBE) in 37 fractions for 2 lesions. Results: The median follow-up period was 31 (10 - 46) months, and the numbers of survivors, deaths from primary diseases, and deaths from other diseases were 3, 1, and 1, respectively. There were no local recurrences, one intrahepatic metastasis, one lung metastasis, and one intrathoracic metastasis. Conclusion: Although experiences on a small number of patients cannot conclude things, we believe that PBT can be a reasonable choice of radical treatment for HCC occurring after the Fontan procedure.