Long term outcomes of stereotactic body radiation therapy for hepatocellular carcinoma without macrovascular invasion.

ABSTRACT

BACKGROUND: Stereotactic Body Radiation Therapy (SBRT) is a non-invasive ablative treatment for hepatocellular carcinoma (HCC). This report aimed to address the limited availability of long-term outcomes after SBRT for HCC from North America. METHODS: Localized HCC patients without vascular invasion, who were ineligible for other liver-directed therapies and treated with SBRT at the University of Toronto or University of Michigan, were pooled to determine overall survival (OS), cumulative recurrence rates, and ≥ grade-3 toxicity. Multivariable analysis determined factors affecting OS and local recurrence rates. RESULTS: In 297 patients with 436 HCCs (42% > 3 cm), one-, three- and five-year OS was 77·3%, 39·0% and 24·1%, respectively. On Cox proportional hazards regression analysis, liver transplant after SBRT, Child-Pugh A liver function, alpha-fetoprotein ≤ 10 ng/ml, and Eastern Co-operative Oncology Group performance status 0 significantly improved OS (hazard ratio [HR] = 0·06, 95% confidence interval [CI- 0·02-0·25; p<0·001; HR = 0·42, 95% CI = 0·29-0·60, p<0·001; HR = 0·61, 95% CI- 0·44-0·83; p=0·002 and HR = 0·71, 95% CI = 0·51-0·97, p=0·034, respectively). Cumulative local recurrence was 6·3% (95% CI = 0.03-0.09) and 13·3% (95% CI = 0.06-0.21) at one and three years, respectively. Using Cox regression modelling, local control was significantly higher using breath-hold motion management and in HCC smaller than 3 cm (HR = 0.52, 95% CI = 0.58-0.98; p=0.042 and HR = 0.53, 95% CI = 0.26-0.98; p=0.042, respectively). Worsening of Child-Pugh score by ≥2 points three months after SBRT was seen in 15.9%. CONCLUSIONS: SBRT confers high local control and long-term survival in a substantial proportion of HCC patients unsuitable for, or refractory to standard loco-regional treatments. Liver transplant should be considered if appropriate downsizing occurs after SBRT.