Abstract: Objective To analyze the prediction value of indocyanine green 15-minute clearance rate (ICG R15) for radiation-induced liver damage (RILD) in patients with primary hepatocellular carcinoma (HCC) undergoing stereotactic body radiotherapy (SBRT). Methods From October 1st, 2016 to August 31st, 2017, 150 patients with HCC employing SBRT were enrolled in this prospective study. The ICG R15 values were measured 1 week before treatment, and biochemical parameters were measured at least 1 year after SBRT. RILD was diagnosed according to the published criteria. The relationship between the ICG R15 and RILD were analyzed in these 150 patients. Results Typical RILD occurred in 14 patients (93.3%), and atypical RILD occurred in 1 patient (6.7%). ICG R15 in Child-Pugh B patients (34.275±16.544%) was significantly higher than that in Child-Pugh A patients (8.936±11.134 %). ICG R15 cut-off value was defined as 11.3% by the receiver operating characteristic curve, whose corresponding sensitivity and specificity were 0.667 and 0.778, respectively. RILD occurred in 5 patients when ICG R15 was less than 11.3% and 10 patients when ICG R15 was more than 11.3% (P=0.001). Multivariate analysis showed that only ICG R15 before radiotherapy showed statistical significance in predicting RILD (RR 9.578, 95%CI: 2.278~40.264). Conclusion ICG R15 value is an effective predictor of RILD in patients with HCC after SBRT.

Key words: Primary hepatocellular carcinoma, Indocyanine green 15 min clearance rate, Radiation-induced liver damage, Stereotactic body radiotherapy