A comparison of carbon ion radiotherapy and transarterial chemoembolization treatment outcomes for single hepatocellular carcinoma: a propensity score matching study

BACKGROUND: We compared clinical outcomes of carbon ion radiotherapy and transarterial chemoembolization in the treatment of hepatocellular carcinoma. METHODS: Data of 477 patients with hepatocellular carcinoma who had undergone carbon ion radiotherapy or transarterial chemoembolization between April 2007 and September 2016 were retrospectively reviewed. Treatment naïve patients with single HCC, who underwent carbon ion radiotherapy or transarterial chemoembolization as a primary treatment were included. Clinical outcomes of the treatments were compared after utilizing propensity score matching. RESULTS: Of 124 patients who received carbon ion radiotherapy and 353 patients who received transarterial chemoembolization, 31 and 23 patients met our inclusion criteria, respectively. After utilizing propensity score matching, 17 matched pairs of patients from each treatment group were analyzed. The median follow-up durations after carbon ion radiotherapy and transarterial chemoembolization were 43 and 32 months, respectively. The 3-year overall survival, local control, and progression-free survival rates in the carbon ion radiotherapy versus transarterial chemoembolization groups were 88% versus 58% (p < 0.05), 80% versus 26% (p < 0.01), and 51% versus 15% (p < 0.05), respectively. CONCLUSIONS: Carbon ion radiotherapy showed more favorable clinical outcomes than did transarterial chemoembolization for patients with single hepatocellular carcinoma after matching patient characteristics utilizing propensity score matching. Further studies with larger patient numbers are required to confirm our results. TRIAL REGISTRATION: UMIN000036455: date of registration 22 March 2019, retrospectively registered.