title: Stereotactic body radiation therapy in hepatocellular carcinoma: Optimal treatment strategies based on liver segmentation and functional hepatic reserve.
abstract: OBJECTIVE
  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.
  
  
  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 × 10-20 Gy, 4-6 × 8-10 Gy, and 10 × 5-5.5 Gy. Based on previous SBRT studies, and in consideration of tumor size and CP classification, we proposed 3 × 15-25 Gy for patients with tumor size <3 cm and adequate liver reserve (CP-A score 5), 5 × 10-12 Gy for patients with tumor sizes between 3 and 5 cm or inadequate liver reserve (CP-A score 6), and 10 × 5-5.5 Gy for patients with tumor size >5 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.
authors.affiliation: Department of Radiation Oncology, Chung-Kang Branch, Cheng-Ching General Hospital, Taichung, Taiwan.
authors.forename: Po-Ming
authors.initials: PM
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, Chung-Kang Branch, Cheng-Ching General Hospital, Taichung, Taiwan.
authors.forename: Na-Na
authors.initials: NN
authors.lastname: Chung
authors.affiliation: Department of Radiation Oncology, Chung-Kang Branch, Cheng-Ching General Hospital, Taichung, Taiwan ; Department of Healthcare Administration, Asia University, Taichung, Taiwan.
authors.forename: Wei-Chung
authors.initials: WC
authors.lastname: Hsu
authors.affiliation: Department of Radiation Oncology, Chung-Kang Branch, Cheng-Ching General Hospital, Taichung, Taiwan.
authors.forename: Feng-Ling
authors.initials: FL
authors.lastname: Chang
authors.affiliation: Department of Radiation Oncology, Chung-Kang Branch, Cheng-Ching General Hospital, Taichung, Taiwan.
authors.forename: Chin-Jyh
authors.initials: CJ
authors.lastname: Jang
authors.affiliation: Radiotherapy and Radiosurgery Department, Humanitas Cancer Center, Istituto Clinico Humanitas, Rozzano, Milano, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Scorsetti
keywords: Hepatitis B virus; Hepatocellular carcinoma; Segment; Stereotactic body radiation therapy