Fig. 1

a Cumulative number of centers practicing liver SBRT and number of treated lesions from 1997 to 2014. b Change of prescribed biologically effective dose (BED) for SBRT liver oligometastases from 1997 to 2014
a Cumulative number of centers practicing liver SBRT and number of treated lesions from 1997 to 2014. b Change of prescribed biologically effective dose (BED) for SBRT liver oligometastases from 1997 to 2014