RESEARCH

Full list of author information is available at the end of the articleChild-Pugh score (CP score), Dosimetric parameter, The deterioration of hepatic function Background Hepatocellular carcinoma (HCC), which is one of the most common malignant carcinomas worldwide, is a fatal disease that might cause death with severe compli-cation if treated improperly [1,2]. Although a surgical resection is considered the treatment of choice, many patients are either inoperable or the tumor is unresect-able at the time of diagnosis. In these cases, transarterial chemoembolization (TACE), percutaneous ethanol injec-tion (PEI), and radiofrequency ablation (RFA) have been used [3-5]. In contrast, radiotherapy (RT) had not been widely used for the treatment of HCC because of the low dose of radiation tolerable for the entire liver, which was not effective for tumor control [6,7]. However, recently reported studies showed that partial volume irradiation of the liver is feasible and a useful tool for the treatment of HCC within an acceptable range of hepatic toxicity [8-11]. In the use of RT for the treatment of HCC, radiation-induced hepatic toxicity (RIHT) is considered a significan