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 400 IU/ml and a
radiologically compatible feature with HCC in one or more CT/MRI/angiograms

- (ii) the presence of risk factors including hepatitis B or C virus and liver
cirrhosis, a serum a-fetoprotein (AFP) level less than 400 IU/ml, and a
radiologically compatible feature with HCC in two or more CT/MRI/angiograms or
(iii) histological confirmation

- HCC patients who were not prospective suitable or refused for any other treatment,
such as surgery or local ablation therapy, or recurrent or residual tumor after other
treatments.

- Without evidence of extrahepatic metastasis

- All target tumors must be encompassable within single irradiation field (12x12 cm
maximum)

- No previous treatment to target tumors by other forms of RT

- Digestive tract not in contact with clinical target volume

- Liver function of Child-Pugh class A or B

- 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 ≥ 25,000/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

Exclusion Criteria:

- Evidence of extrahepatic metastasis

- Age < 18 years

- Liver function of Child-Pugh class C

- 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

- Diffusely infiltrating tumor which is difficult to define the gross tumor volume
accurately

- Multicentric HCCs, except for those with the following two conditions:

- (i) multinodular aggregating HCC that could be encompassed by single clinical
target volume and within single irradiation field (15x15 cm maximum)

- (ii) lesions other than targeted tumor that were judged as controlled with prior
surgery and/or local ablation therapy

- Digestive tract in contact with clinical target volume

- Pregnant or breast feeding status

- Previous history uncontrolled other malignancies within 2 years