Stereotactic ablative radiotherapy in the treatment of hepatocellular carcinoma >3cm.

Abstract

Stereotactic ablative radiotherapy (SABR) is a safe treatment approach for hepatocellular carcinoma (HCC) with comparable results to other local therapies. For lesions larger than 3cm, no definitive standard treatment is present and several options are available. We retrospectively review local control (LC) and survival results of SABR in patients with HCC lesions >3cm. Between 2012 and 2015, we treated 29 patients (39 lesions) having histological or radiological diagnosis of HCC and at least one lesion sized >3cm. Patients were prescribed 36-48Gy in 3-5 fractions (mainly 16Gy×3 fractions or 8Gy×5 fractions), in 3-5 consecutive days. A total of 15 lesions (52%) had complete, while 10 (34%) had partial remission; 3 (11%) had a stable disease. Mean time for CR achievement was 5.8months (range 1-17). One- and two-year actuarial LCwas 100%. Moreover, 1- and 2-year progression-free (PFS), cancer-specific and overall survival were 57.9% [standard error (SE) 0.09; 95% CI 36.9-74.2] and 41.2% (SE 0.12; 95% CI 17.7-63.5), 80.7% (SE 0.08; 95% CI 59.6-91.5) and 63.3% (SE 0.11; 95% CI 38.4-80.3), 71.7% (SE 0.08; 95% CI 51.2-84.7) and 56.2% (SE 0.10; 95% CI 33.8-73.6). On multivariate analysis, achieving a CR within the target lesion had a borderline significance with respect to PFS (HR 0.83; SE=0.014; z -1.15; p=0.095; 95% CI 0.71-7.45). Time between HCC diagnosis and SABR delivery (<vs>12months) was significantly correlated with OS (HR 16.5; SE 21.5; z=2.14; p=0.032; 95% CI 1.27-213.3) as CLIP score (score: 0-1 vs 2) (HR 5.6; SE 4.6; z=2.10; p=0.036; 95% CI 1.11-27.8). A total of 6 major toxic events (G3-G4) were recorded (20%). In 2 patients (6%), a radiation-induced liver disease was seen. In conclusion, SABR provided LC and survival rates comparable to other local therapies for patients with HCC lesion sized >3cm, with acceptable toxicity profile.