@article{oai:repo.qst.go.jp:00081683, author = {Yu-Lun, Tsai and Takei, Hideyuki and Iizumi, Takashi and Okumura, Toshiyuki and Sekino, Yuta and Numajiri, Haruko and Ishikawa, Hitoshi and Sakae, Takeji and Sakurai, Hideyuki and Hideyuki, Takei and Hitoshi, Ishikawa and Takeji, Sakae and Hideyuki, Sakurai}, issue = {1}, journal = {Journal of Radiation Research}, month = {Jan}, note = {Unirradiated liver volume (ULV) preservation rate is an important factor associated with radiation-induced liverdisease (RILD) in patients with hepatocellular carcinoma (HCC) undergoing proton beam therapy (PBT). The purpose of this study is to identify the predictors for ULV preservation and quantify the capacity of proton beamsin normal liver sparing during PBT. We reviewed planning data of 92 patients with single intrahepatic HCC tumors undergoing PBT. The potential clinical and planning factors that may affect ULV preservation were involved in multiple linear regression forULVpreservation rate.The significant factorswere determined to be predictors and their influences were quantified. The median ULV preservation rate was 62.08%. All the assessed clinical factors showed significant effects on ULV preservation rate: clinical target volume (CTV), P <0.001; portal vein tumor thrombosis (PVTT), P = 0.010; left lobe tumor, P = 0.010. In contrast, none of the planning factors demonstrated significance.The coefficients of significant factors in multiple linear regression were 60.85 for intercept,−0.02 for CTV,−9.01 for PVTT and 8.31 for left lobe tumors. The capacity of proton beams to spare normal liver tissue during PBT for HCC ismainly affected by clinical factors. The baseline of theULV preservation rate is 60.85%, decreasing 0.02% with each milliliter of CTV increase and 9.01% for tumors with PVTT, and increasing 8.31% for tumors limited to the left lobe.Further clinical studies should be carried out to correlate our dosimetric findings with clinical outcomes.}, pages = {133--141}, title = {Capacity of proton beams in preserving normal liver tissue during proton beam therapy for hepatocellular carcinoma}, volume = {62}, year = {2021} }