Stereotactic body radiation therapy in hepatocellular carcinoma: Optimal treatment strategies based on liver segmentation and functional hepatic reserve

Abstract

Aim

To discuss current dosage for stereotactic body radiation therapy (SBRT) in hepatocellular carcinoma (HCC) patients and suggest alternative treatment strategies according to liver segmentation as defined by the Couinaud classification.

Background

SBRT is a safe and effective alternative treatment for HCC patients who are unable to undergo liver ablation/resection. However, the SBRT fractionation schemes and treatment planning strategies are not well established.

Materials and methods

In this article, the latest developments and key findings from research studies exploring the efficacy of SBRT fractionation schemes for treatment of HCC are reviewed. Patients’ characteristics, fractionation schemes, treatment outcomes and toxicities were compiled. Special attention was focused on SBRT fractionation approaches that take into consideration liver segmentation according to the Couinaud classification and functional hepatic reserve based on Child–Pugh (CP) liver cirrhosis classification.

Results

The most common SBRT fractionation schemes for HCC were 3[[ce:hsp sp="0.25"/]]×[[ce:hsp sp="0.25"/]]10–20[[ce:hsp sp="0.25"/]]Gy, 4–6[[ce:hsp sp="0.25"/]]×[[ce:hsp sp="0.25"/]]8–10[[ce:hsp sp="0.25"/]]Gy, and 10[[ce:hsp sp="0.25"/]]×[[ce:hsp sp="0.25"/]]5–5.5[[ce:hsp sp="0.25"/]]Gy. Based on previous SBRT studies, and in consideration of tumor size and CP classification, we proposed 3[[ce:hsp sp="0.25"/]]×[[ce:hsp sp="0.25"/]]15–25[[ce:hsp sp="0.25"/]]Gy for patients with tumor size <3[[ce:hsp sp="0.25"/]]cm and adequate liver reserve (CP-A score 5), 5[[ce:hsp sp="0.25"/]]×[[ce:hsp sp="0.25"/]]10–12[[ce:hsp sp="0.25"/]]Gy for patients with tumor sizes between 3 and 5[[ce:hsp sp="0.25"/]]cm or inadequate liver reserve (CP-A score 6), and 10[[ce:hsp sp="0.25"/]]×[[ce:hsp sp="0.25"/]]5–5.5[[ce:hsp sp="0.25"/]]Gy for patients with tumor size >5[[ce:hsp sp="0.25"/]]cm or CP-B score.

Conclusions

Treatment schemes in SBRT for HCC vary according to liver segmentation and functional hepatic reserve. Further prospective studies may be necessary to identify the optimal dose of SBRT for HCC.