Long-Term Results of Stereotactic Body Radiation Therapy for Patients With Small Hepatocellular Carcinoma Ineligible for Resection or Ablation Therapies

Abstract

To evaluate the long-term outcome of stereotactic body radiotherapy (SBRT) in patients with small hepatocellular carcinoma (HCC) who are ineligible for resection or ablation therapies. We previously published the efficacy and safety of SBRT in 65 patients with 74 HCC who were ineligible for resection or ablation therapies. The following inclusion criteria for curative SBRT were used: (i) age over 20 years; (ii) an Eastern Cooperative Oncology Group Performance Status of 0–2; (iii) Child–Turcotte–Pugh (CTP) class A or B; (iv) less than three HCC nodules, each up to 50 mm in diameter without portal venous thrombosis or extrahepatic metastases; (v) inoperability because of poor general condition or surgery refusal; and (vi) unsuitability for radiofrequency ablation because of tumor location (on the liver surface, particularly high risk of pneumothorax, or near the porta hepatis), tumor invisibility on ultrasonography, or bleeding tendencies (platelet count, ≤50,000/mL; prothrombin activity, ≤50%). Patients were treated with the prescribed dose of 48 Gy in four fractions at the isocenter. CTP scoring was used to classify 56 and 9 patients into classes A and B, respectively. Local progression was defined as irradiated tumor growth on a dynamic computed tomography follow-up. Tumor responses were assessed according to the modified Response Evaluation Criteria in Solid Tumors. Treatment-related toxicities were evaluated according to the Common Terminology Criteria for Adverse Events version 4.0. We also updated the survival and tumor control outcomes for these same patients, with 2 years’ additional follow-up. In previous study, the median follow-up period was 26 months (range, 3–60), and 29 months in survivors (range, 16–60). The 2-year overall survival and local control rates were 76.0% (95% confidence interval [CI], 65.4–86.7%) and 100% (95% CI, 100%), respectively. In this study, the median follow-up period at the time of evaluation was 41 months (range, 3–73), and 58 months in survivors (range, 24–73). The 3-year and 5-year overall survival rates were 56.3% (95% CI, 44.1–68.5%) and 40.9% (95% CI, 28.0–53.8%), respectively. The 3-year and 5-year local control rates were both 100% (95% CI, 100%). Grade 3 or higher toxicities were observed in 15 (23.1%) patients. During the 2 years of additional follow-up period, the proportion of patients who had grade 3 or higher toxicities did not increase. The incidence of grade 3 or higher toxicities was higher in CTP class B than in class A (P = 0.0127). SBRT was effective and relatively safe for patients with small HCC who were ineligible for resection or ablation therapies even during longer follow-up times.