Does HCC Etiology Impact the Efficacy of Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma? An Asian Liver Radiation Therapy Group Study

Abstract

Background/Purpose

The Asian Liver Radiation Therapy Study Group has formed a large and detailed multinational database of outcomes following stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC). Here, we explored the potential impact of HCC etiology on SBRT efficacy. Tumor control probability (TCP) models were established to estimate the likelihood of local control (LC).

Methods

Data from 415 patients who were treated with SBRT for HCC were reviewed. Cox proportional hazards models were used to identify key predictors of LC. TCP models accounting for biologic effective dose (BED) and tumor diameter were generated to quantify associations between etiology and LC.

Results

Cox models demonstrated that hepatitis C virus (HCV) infection was associated with favorable LC following SBRT (HR=0.52, 95% CI 0.04–0.96, p=0.036). The 2-year LC rate for patients with HCV etiology was 88%, compared to 78% for other patients. Small tumor and high BED were also associated with favorable LC. TCP models demonstrated a 10–20% absolute increase in predicted LC across the range of SBRT doses and tumor sizes.

Conclusion

We found a novel association between HCV status and LC after SBRT for HCC that warrants further exploration. If validated in other datasets, our findings could help clinicians tailor SBRT schedules.

Graphical Abstract

Keywords:

• tumor control probability
• hepatocellular carcinoma
• stereotactic body radiation therapy
• hepatitis C virus

Abbreviations

BED, biologically effective dose; CT, computed tomography; HBV, hepatitis B virus; HCV, hepatitis C virus; HR, hazard ratio; LC, local control; MRI, magnetic resonance imaging; SBRT, stereotactic body radiation therapy; TCP, tumor control probability.

Grand Support

This work was supported by the Dong-A research fund (Grant number 2018-31-0904) and an Accuray research grant.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

Nitin Ohri reports personal fees from Merck, personal fees from AstraZeneca, personal fees from Genentech, outside the submitted work. The authors report no other conflicts of interest in this work.