多b值DWI对肝脏转移瘤化疗早期疗效评估的初步研究

Value of multiple b-value DWI imaging in prediction and early assessment of response of hepatic metastases to chemotherapy

目的探讨多b值扩散加权成像(DWI)在肝脏转移瘤化疗早期疗效评价中的应用价值。方法选择肝转移瘤患者19例33个病灶,在治疗前后分别行多b值的DWI扫描,分别拟合出各类表观扩散系数图(ADC10b图、ADC3b图、ADClow图、ADChigh图)并获得相应的ADC值。ADClow图与ADChigh图减影后得ADCperf图,获得ADCperf值;并以实体瘤疗效评价标准(RECIST)评价化疗疗效,比较治疗前后ADC值变化。结果治疗后8例15个肝转移病灶对化疗有效,11例18个肝转移病灶对化疗无效。治疗有效组在化疗前ADC值(ADC10b、ADC3b、ADChigh及ADClow)低于化疗无效组,而ADCperf值高于无效组,差异均有统计学意义(P<0.05)。化疗有效组化疗后ADC值(ADC10b、ADC3b、ADChigh及ADClow)均有明显增高,ADCperf值减低,治疗前后差异有统计学意义(P<0.05)。而化疗无效组的ADC值无明显变化(P>0.05)。结论多b值DWI作为一种无创性MRI功能成像技术可以对肝转移瘤化疗疗效作出早期评估,能协助临床制定个体化方案。

Objective To investigate the role of multiple b--value DWI in predicting response to chemother- apy in patients with hepatic metastases. Methods Multiple b--value DWI imaging were performed before and after chemotherapy for 33 hepatic metastases in 19 patients. The ADC values of ADClow, ADChigh, ADCperf, ADC3b and ADC10b maps were calculated. Lesions were classified as either responding or nonre- sponding according to RECIST. ADC values were compared with before and after chemotherapy in patients. Results 15 responding metastatic lesions in 8 patients and 18 nonresponding metastatic lesions in 11 pa- tients were evaluated. Pretherapy mean ADC （ADC10b, ADC3b, ADChigh and ADClow） in responding lesions were significantly lower and ADCperf were significantly higher than those of nonresponding lesions （P 〈0.05）. An in- crease in ADC （ADC10b, ADC3b, ADChigh and ADClow） and a decrease in ADCperf was observed in responding lesions but not in nonresponding lesions （P 〈0.05）. Conclusion Multiple h--value DWI could be a promising tool for predicting and assessing the early response of hepatic metastases to chemotherapy.