This phase 3 study is to evaluate the effectiveness of the comparison between radiofrequency ablation and hypofractionated proton beam radiation.

The sample size for this study was based on a non-inferiority design. Primary objective: estimate local progression-free survival (LPFS) rate in two treatments Primary endpoint: 2-year LPFS rate Expected 2-year LPFS rate in the RFA: 85% Accural time and follow up time: 24 months and 24 months, respectively. Precision for 2-year LPFS rate estimation: Allowing a difference of 15% as the non-inferiority margin, with a power of 80% and a type I error level of 5%, evaluable 68 patients are required.

Considering 5% of follow-up loss, we need 72 patients in each arm, so a total of 144 patients will be enrolled.

Inclusion Criteria:

• HCC diagnosed as (i) the presence of risk factors including hepatitis B or C virus and liver cirrhosis, a serum a-fetoprotein (AFP) level greater than 200 IU/ml and a radiologically compatible feature with HCC in one or more CT/MRI/angiograms, or (ii) the presence of risk factors including hepatitis B or C virus and liver cirrhosis, a serum a-fetoprotein (AFP) level less than 200 IU/ml, and a radiologically compatible feature with HCC in two or more CT/MRI/angiograms or (iii) histological confirmation
• HCC patients who had recurrent or residual tumor after other treatments
• without evidence of extrahepatic metastasis
• the largest diameter of tumor should be less than 3cm, and the number of tumor ≤2
• no previous treatment to target tumors by other forms of RT
• liver function of Child-Pugh class A or B7 (Child-Pugh score of ≤7)
• Age of ≥18 years
• performance status of 0 to 2 on the Eastern Cooperative Oncology Group (ECOG) score
• WBC count ≥ 2,000/mm3; hemoglobin level ≥ 7.5 g/dL; platelet count ≥ 50,000/mm3; and adequate hepatic function (total bilirubin ≤ 3.0 mg/dL; AST and ALT < 5.0× upper limit of normal; no ascites)
• no serious comorbidities other than liver cirrhosis
• written informed consent

Exclusion Criteria:

• evidence of extrahepatic metastasis
• age < 18 years
• liver function of Child-Pugh class B8-9 and C (Child-Pugh score of >7) or uncontrolled cases of active chronic hepatitis B
• previous history of other forms of RT adjacent to target tumors
• poor performance status of 3 to 4 on the Eastern Cooperative Oncology Group (ECOG) score
• pregnant or breast feeding status
• previous history uncontrolled other malignancies within 2 years