肝癌适形放疗后放射性肝病的剂量体积直方图分析

Dose-volume histogram analysis on radiation-induced liver disease (RILD) after conformal radiotherapy for primary liver carcinoma

目的放射性肝病(RILD)是原发性肝癌(PLC)大分割三维适形放射治疗(3DCRT)后最严重的并发症。然而,放射性肝病尚无有效的预测因素。本研究旨在探讨影响肝硬化Child-Pugh A级PLC患者大分割3DCRT后RILD的剂量学因素。方法2000年8月至2007年6月采用8MVX线直线加速器对114例肝硬化Child-Pugh A级PLC患者放疗符合入组条件进入本研究,其中男104例,女10例,中位年龄45岁(23～79岁)。B超或CT提示有门脉癌栓者22例,GTV为(378.3±308.1)cm3,分割剂量4～6Gy(中位4.6Gy),每周3次,隔日1次。肿瘤剂量40～68Gy(中位53Gy),总疗程3～6周(中位4周)。38例患者放疗前接受过经动脉化疗栓塞术(TACE)治疗,所有病人均有包括DVH图在内的完整的剂量学数据。结果所有患者3DCRT治疗后中位随访期19个月(1～79个月),发生RILD9例,发生率为7.9%(9/114)。单因素分析发现GTV和V5、V10、V15、V20、V25、V30、V35、V40与RILD相关;多因素分析发现GTV和V20是独立影响因素(P=0.015和0.003)。V20=48.5%作为耐受剂量,预测RILD准确度达0.763,敏感度为0.889,特异度为0.752。结论对于行3DCRT治疗后的肝硬化Child-PughA级的PLC患者,V20是预测RILD有独特意义的影响因素。

Objective Radiation-induced liver disease （RILD） has been considered as the most severe complication in liver irradiation. However, RILD does not have effective predictors. This study was to identify dosimetric predictors for RILD in primary liver carcinoma （PLC） patients with Child-Pugh grade A cirrhosis after being treated with hypofractionated conformal radiotherapy （CRT）. Methods Between August 2000 and June 2007 ,a total of 114 eligible patients were included. The median age was 45 years （23 - 79 years）. Portal vein thrombosis （PVT） was detected in 22 patients. The mean gross tumor volume （GTV） was （378.3 ± 308. 1） cm^3. A median dose of 53 Gy （40 -68 Gy） was delivered to the PLC by hypofractionated CRT （three fractions per week） with a median fraction size of 4. 6 Gy （4 -6 Gy）. Thirty-eight patients had previously received transcatheter arterial chemoembolization. All patients had intact treatment planning data, including liver dose-volume histograms before treatment. Results Patients were followed up for 1-79 months （ median 19 months） after completion of the irradiation. RILD was diagnosed in 9 （7. 9% ） patients. Univariate analyses revealed that GTV and the percent of normal liver volume exceeding 5-40 Gy （V5-40） were related to the risk of developing RILD. Multivariate analyses showed that only GTV （P = 0. 015 ） and V20 （P = 0. 003） were independent predictors. When using V20 = 48.5% as tolerated dose to predict RILD, the accuracy, sensitivity and specificity was 76. 3% ,88.9% and 75.2% ,respectively. Conclusions V20 is a unique significant dosimetric predictor to evaluate RILD risks for PLC patients with Child-Pugh grade A cirrhosis after hypofractionated CRT.