The Impact of Beam Angle Configuration of Intensity Modulated Radiation Therapy on the Normal Liver in Advanced Hepatocellular Carcinoma

Abstract

Methods and Materials: We conducted a retrospective study of 163 HCC patients who were treated with conformal RT between January 2008 and December 2009. All patients underwent 4D-CT simulation and a dosee volume histogram (DVH) was generated after RT planning. RT dose was administered according to our in-house protocol of 2.0 5.0 Gy/fraction according to DVH parameters. Patients who had an elevated CP score of 2 or more without progressive disease (PD) within three months were defined as e-CP positive. Results: The objective response to RT was 63.2%, and the median overall survival (OS) was 14.5 months. There were no cases of classic radiation-induced liver disease. In total, 26 out of 144 patients without PD were e-CP positive. Pretreatment CP class, further treatment within 30 days after RT, lymph node metastasis, mean liver dose (MLD), V10 Gy, V20 Gy, V25 Gy, and V30 Gy were significantly correlated with e-CP positivity. The e-CP was developed in 13 of 106 patients (12.3%) with V30Gy of 28.1% and in 13 of 36 patients (36.1%) with > 28.1% (p Z 0.001). RT response and e-CP positivity were both significant prognostic factors for OS. Conclusion: Our data demonstrate that MLD, V10 Gy, V20 Gy, V25 Gy, and V30 Gy are independent doseevolumetric predictors for e-CP positivity in HCC patients treated with conformal RT. V30Gy should be limited to less than 28.1% to minimize the risk of e-CP. Author Disclosure: J. Yu: None. H. Park: None. D. Lim: None. W. Park: None.