Temporal change in liver function after stereotactic body radiation therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) often develops in the setting of chronic liver disease, making preservation of hepatic function central to treatment decisions. Despite this, the temporal change on liver function caused by stereotactic body radiation therapy (SBRT), particularly using objective measures such as the albumin-bilirubin (ALBI) score, remains poorly defined. This retrospective study aimed to measure temporal changes in liver function in patients with HCC treated with SBRT. Comparable data was also obtained from patients treated with microwave ablation (MWA), a liver-directed therapy with negligible impact on hepatic function, acting as a control cohort for estimating changes attributable to underlying cirrhosis rather than treatment.

A total of 126 patients with HCC were included, 72 in the SBRT and 54 in the control cohorts respectively. Biochemical data was extracted before and at 3, 6 and 12 months post-treatment for calculation of albumin-bilirubin (ALBI) and Child-Pugh (CP) scores. Clinical and dosimetric data was obtained for assessment of factors associated with change in liver function following SBRT.

Baseline liver function was similar between the SBRT and control cohorts (ALBI score, -2.30 vs. -2.27, P=0.68). The median lesion size was significantly larger in the SBRT group (37 vs. 20 mm, P<0.01). The control group showed a trend towards a decline in ALBI scores, but did not reach statistical significance at 12 months (P=0.11). In contrast, the SBRT group exhibited a gradual and statistically significant decline in ALBI scores from 3 months (P=0.01) through to 12 months post-treatment (P<0.01). Factors significantly correlated with changes in ALBI at 6 months included tumour lesion size (P=0.01), planning target volume (PTV) size (P<0.01), mean liver dose (MLD) (P=0.05), and multifocality (P=0.03).

Liver function as measured by ALBI score gradually declines following SBRT for HCC, with larger lesion size associated with greater change. However, this change is only significant in a minority of our cohort with added contributions from non-treatment-related factors including co-existing cirrhosis.