With the growing use of stereotactic body radiotherapy (SBRT), there is a need to better understand liver tolerance, much of which is based on conventionally fractionated radiation regimens. Recent data from our group (Osmundson et al. IJROBP 2015) has shown a new type of liver toxicity caused by damage to the central liver, analogous to the toxicities observed when delivering SBRT to central lung tumors. In the current study, using an expanded dataset of patients, we found that this dose relationship to the central liver was still present but only for patients treated with primary liver tumors. In addition, using dosimetric and non-dosimetric factors associated with toxicity, we were able to construct a predictive nomogram to help the radiation oncologist at the time of treatment planning when considering SBRT for these patients.  Most importantly, these data are an important step in furthering our understanding of this new entity of treatment-related morbidity upon which we hope more research is built.