Stereotactic Body Radiation Therapy For 45 Patients with Inoperable Hepatic Metastasis

Abstract

This study was conducted to evaluate the feasibility and safety of stereotactic body radiotherapy (SBRT) for inoperable hepatic metastases(HMs). From May 2007 to November 2014, 45 patients (male:female=20:25) with inoperable HMs were enrolled, and median age was 58 (range:25-83) years old. Median KPS was 80. The main primary disease were colorectal cancer (31.1%), breast cancer(20%), and lung cancer(13.3%). 21 cases (46.7%) had extrahepatic metastases. 52 lesions were treated, with median GTV of 10.1ml (0.3-175.2ml) and PTV of 29.8ml (5.0-209.6ml). Bellyband was used to reduce respiratory tumor motion. CT images were fused with MRI to be contoured. Image-guided Radiation Therapy (IGRT) was used during each fraction. Dose regimens were 45 Gy in 3 fractions, 60 Gy in 10 to 15 fractions, and for lesions adjacent to vital organs such as gastrointestinal tract and porta hepatis, 60 Gy in 20 fractions was delivered. Six large volume lesions were contracted 3mm to get boost regions with doses boosting to 66 or 75Gy. Median doses of PTV and BED were 60 Gy (40-60 Gy) and 90 Gy(60-132 Gy). Survival analysis was assessed with Kaplan–Meier method. Toxicities were assessed by CTCAE version 4.0. Median follow-up time was 23.5 months (m). CR and PR rates were 82.1% and 17.9%, respectively. The 1-year LC, DFS, OS and 2-year OS were 94.1%, 26.7%, 91.1% and 54%, respectively. Median intrahepatic progress-free-survival, PFS, OS were 11.5m (95%CI:2.9-20.2), 10.2m (95%CI:0.6-19.7) and 26.0m (95%CI:21.4-30.6), respectively. Primary tumor types (p=0.016) and extrahepatic metastases (p=0.023) were progostic factors of OS. 6 cases died of new intrahepatic metastases, abnormal liver function , and local failure. No Grade 3 toxicities were seen. SBRT was an efficient and safe treatment for inoperable hepatic metastases, dose regimens should be adjusted appropriately considering the location of lesions.