Lyman NTCP model analysis of radiaton-induced liver disease in hypofractionated conformal radiotherapy for primary liver carcinoma / 中华放射肿瘤学杂志

ABSTRACT

Objective To-identify the factors associated with radiation-induced liver disease (RILD) and to describe the probability of RILD using the Lyman normal tissue complication(NTCP) model for primary liver carcinoma(PLC) treated with hypofractionated conformal therapy (CRT).Methods A total of 109 PLC patients treated with hypofractionated CRT were prospectively followed according to the Child-Pugh classification for liver cirrhosis,93 patients in class A and 16 in class B.The mean dose of radi- ation to the isocenter was (53.5?5.5) Gy,fractions of (4.8?0.5) Gy,with interfraction interval of 48 hours and irradiation 3 times per week.Maximal likelihood analysis yielded the best estimates of parameters of the Lyman NTCP model for all patients;Child-Pugh A and Child-Pugh B patients,respectively.Results Of all the patients,17 developed RILD (17/109),8 in Child-Pugh A(8/93 ) and 9 in Child-Pugh B(9/ 16).By multivariate analysis,only the Child-Pugh Grade of liver cirrhosis was the independent factor (P= 0.000) associated with the developing of RILD.The best estimates of the NTCP parameters for all 109 pa- tients were n=1.1,m=0.35 and TD_(50) (1)=38.5 Gy.The n,m,TD_(50) (1) estimated from patients with Child-Pugh A was 1.1,0.28,40.5 Gy,respectively,compared with 0.7,0.43,23 Gy respectively,for patients with Child-Pugh B.Conclusions Primary liver cancer patients who possess Child-Pugh B cirrho- sis would present a significantly greater susceptibility to RILD after hypofractionated CRT than patients with Child-Pugh A cirrhosis.The predominant risk factor for developing RILD is the severity of hepatic cirrhosis in the liver of PLC patients.