A prospective study of the safety and efficacy of liver stereotactic body radiotherapy in patients with and without prior liver-directed therapy

Background and purpose: To evaluate the safety and efficacy of liver stereotactic body radiotherapy (SBRT), and examine potential factors impacting outcomes including prior liver-directed therapy. Materials and methods: Patients with ECOG 0–1, Child-Pugh Class A or B, and primary hepatocellular carcinoma (HCC) or liver metastases unsuitable for surgical resection or ablation were eligible for a prospective single arm trial. SBRT was delivered with a CyberKnife system to 45 Gy in 3 fractions with a predetermined dose de-escalation scheme. Adverse events, local control, and survival were assessed. Results: A total of 30 patients were enrolled. Eleven patients (37%) had HCC and 19 (63%) patients had liver metastases. Fourteen patients (47%) had prior liver-directed therapies including nine with liver resection, seven with trans-arterial chemoembolization, and six with radiofrequency ablation. Cumulative grade 2 and 3 acute toxicity occurred in 47% and 7% of patients, respectively. Similar rates of ≥grade 2 acute toxicity were observed between patients who had prior liver-directed treatments and those who did not. At a median follow-up of 12.7 months, 1-year local control and overall survival were 81% and 62%, respectively. Prior liver-directed therapy did not affect local control or survival. Conclusions: Liver SBRT is a safe and effective treatment even in the setting of prior liver-directed surgical and ablative therapies.