Stereotactic Body Radiotherapy For Liver Metastasis Of Colorectal Cancer

Background:The most common metastatic lesion in the liver is from colorectal cancer(CRC).In this study,we observed the efficacy and side effects of stereotactic body radiation therapy(SBRT)in the treatment of colorectal liver metastasis(CRLM),so as to prepare for further clinical study.Methods:Patients suffered with CRLM treated in Shanghai East Hospital with SBRT were enrolled.The medium radiation dose for liver metastasis was 50Gy(36-50Gy).Cone beam computed tomography(CBCT)was used for each patient every day to ensure treatment accuracy.Regular blood tests,computed tomography(CT)or magnetic resonance imaging(MRI)were needed until the disease progression or patients dead.Kaplan-Meier analysis was used to calculate overall survival(OS),progression free survival(PFS)and local control(LC).Log-rank was used for univariate analysis,Cox regression analysis was used to analyze the independent prognostic factors of OS,PFS and LC.Toxicity was estimated by Common Terminology Criteria for Adverse Events 5.0(CTCAE 5.0).Results:35 patients with 53 liver metastasis were enrolled.The median follow-up time was 9.83 months(1.8-42.3 months).The medium diameter of the treated liver metastasis was 2.22cm(1.08-6.52cm)and medium volume was 4.9cm3(0.4-148.1 cm3).14 patients dead at the end of the study.The 1-year and 2-year OS rates were 61.4%and 41.3%.11 patients developed disease progression,and the 1-year and 2-year PFS rates were 44.9%and 10%,respectively.Complete response(CR)was achieved in 4(7.5%)lesions,partial response(PR)in 10(18.9%),stable disease(SD)in 28(52.8%),and progressive disease(PD)in 11(20.8%)lesions.The 1-year and 2-year local control rates were 71.1%and 62.2%,respectively.Gross tumor volume(p=0.032)was an independent prognostic factor for OS,while gross tumor volume(p=0.02)and other organ metastases(p=0.026)were independent predictors for LC.The toxicity and side effects of SBRT treatment were mainly limited to grade 1-2.1 patient suffered Grade 3 anemia(Hemoglobin<8.0g/dL)after SBRT.2 patients appeared grade 3 white blood cell decreased,1 case of patient dead for hepatic coma 1 year after SBRT therapy,which was considered to be related to tumor progression.Conclusion:SBRT was a safe and effective local therapy for CRLM with mild and tolerable toxicities.