扩散加权成像对肝动脉灌注3-溴丙酮酸治疗大鼠肝癌早期疗效的评价

目的探讨扩散加权成像（DWI）对3-溴丙酮酸介入治疗大鼠肝癌模型早期疗效的评价。方法20只雄性Wistar大鼠采用瘤块种植法建立肝癌模型，种植术后10d随机分为动脉灌注3-溴丙酮酸组（A组）和生理盐水组（B组），介入术前1d和术后第3天行MRI检测肿瘤体积和表观扩散系数（ADC），术后第3天处死大鼠，病理分析肿瘤坏死率。结果14只大鼠完成介入手术（A=10，B=4）。介入术后第3天A、B组肿瘤平均体积为：482.98±103.88mm^3和255.04±148.30mm^3，A、B组肿瘤体积无统计学差异（P=0.465）；介入术后第3天A、B组肿瘤平均ADC值为（15.15±5.20）×10^-4s／mm^2和（7.57±0.53）×10^-4S／mm^2，A、B组ADC值有统计学差异（P=0.024）。肿瘤坏死率：A组7例为Ⅲ级坏死，2例为Ⅳ级坏死和1例I级坏死，B组4例均为Ⅰ级坏死，治疗后A组肿瘤平均坏死率明显高于B组（P=0.005）；肿瘤病理分级与术后ADC值呈正相关（r=0.897）。结论3一溴丙酮酸对大鼠肝癌模型有较强的抗肿瘤作用，MRI测量肿瘤治疗后早期体积变化不能反映其疗效，尽管ADC值可评估3-溴丙酮酸对大鼠肝癌介入治疗的早期疗效，但尚须进一步研究确立其诊断标准。

Efficacy of ADC in assessing early response to transarterial 3-bromopyruvate therapy of hepatoma in rats

Objective To investigate the efficacy of diffusion-weighted MR imaging in assessing early response of hepatoma to 3-bromopyruvate in Wistar rats. Methods 20 male Wistar rats were implanted with liver cancer and randomized to a group treated with arterial infusion of 3-bromopyruvate or a control group treated with saline. The tumor volume and apparent diffusion coefficient （ADC） were measured on MRI one day before and 2 days after treatment. All of the rats were then sacrificed and the proportion of tumor necrosis was calculated on histopathologic examination. Results The mean tumor volume after completed treatment of 3-bromopyruvate in 10 rats （482.98 ± 103.88 mm^3） was not significantly （P = 0.465） different from that of 4 rats in the control group （255.04 ± 148.30 mm^3）. On the third day after 3-bromopyruvate treatment, the tumor ADC values （15.15 ± 5.20 × 10^-4 s/mm^2） were significantly （P = 0.024） higher than those of the control group （7.57 ± 0.53 × 10^-4 s/mm^2）. The tumor necrosis was grade Ⅲ （7）, grade IV （2）, and grade Ⅰ （1） after 3-bromopyruvate therapy. The mean tumor necrosis rate was significantly （P = 0.005） higher than that of 4 rats in the control group with grade I necrosis. There was positive correlation between the tumor necrosis grades and ADC values （r = 0.897）. Conclusions Transarterial delivery of 3-bromopyruvate has promising anti-tumor effect, which is reflected by the early elevation of tumor ADC values in rat hepatoma model.