乳腺癌新辅助化疗后血流动力学变化的动态增强MRI研究

Breast cancer after neoadjuvant chemotherapy: alteration of kinetic characteristics in dynamic contrast-enhanced MR imaging

目的明确乳腺癌新辅助化疗后动态增强MRI表现强化特征的变化规律。方法组织学活检证实乳腺癌并行乳腺MRI检查的病人80人,根据是否进行新辅助化疗及化疗前后是否进行乳腺MRI检查分为A、B、C三组,均按照统一动态增强MRI扫描方案进行乳腺MRI检查。在Functool诊断工作站采用感兴趣区法测量和比较时间信号强度曲线、最大增强斜率和正性增强积分在A组化疗前后变化以及B组与C组的组间差异。结果A组化疗后残存病变最大增强斜率和正性增强积分分别为242.7±109.2和305.3±110.4,显著低于化疗前500.3±152.0和490.0±130.7(t=6.192,P=0.000;t=4.544,P=0.000);C组的最大增强斜率和正性增强积分分别为330.5±192.9和350.2±119.3,显著低于B组451.9±185.2和436.6±123.7(t=2.202,P=0.032;t=2.579,P=0.013)。A组化疗后曲线类型由Ⅲ/Ⅱ型向Ⅱ/Ⅰ型转变占81.3%(13/16)。B组动态增强的时间信号强度曲线Ⅲ型为主,占48.6%(17/35),而C组时间信号强度曲线以Ⅰ型为主,占62.5%(15/24),各曲线类型在B组和C组的分布有显著差异(χ2=15.88,P=0.000,<0.001)。结论乳腺癌新辅助化疗后残存病变增强速率显著降低,血流量显著减少,时间信号强度曲线类型有由流出型向流入型转变的趋势。

Objective To investigate the alteration of kinetic enhancement of breast cancer after neoadjuvant chemotherapy （NACT） by dynamic contrast-enhanced MR imaging （DCE-MRI）. Methods Eighty patients were enrolled, 18 cases of group A had breast DCE-MRI examination before and after NACT; 35 cases of group B had breast MR examination before or without NACT; 27 cases of grope C had their breast MR examinations after finishing last course of NACT. DCE-MRI was performed on a 1.5 T MR scanner. Type of time signal intensity curve, maximum enhancement slope and positive enhancement integral valve before and after chemotherapy in group A, between group B and group C were compared separately. Results The mean value of maximum enhancement slope and positive enhancement integral after chemotherapy in group A, 242.7±109.2 and 305.3±110.4, were lower than those value before chemotherapy, 500.3±152.0 and 490.0±130.7 （t=6.192, P=0.000; t=4.544, P=0.000）. The mean value of maximum enhancement slope and positive enhancement integral in group C, 330.5±192.9 and 350.2±119.3, were also significantly lower than those in group B, 451.9±185.2 and 436.6±123.7 （t=2.202, P=0.032; t=2.579, P=0.013）. The type of curve before chemotherapy changed from Ⅲ/Ⅱ to Ⅱ/Ⅰ in 81.3% （13/16） of cases with residual disease in group A after chemotherapy. In group B, 48.6 % （17/35） of breast cancer had a type Ⅲ of time signal intensity curve, while 62.5% （15/24） of the cases in group C with breast residual disease after chemotherapy were type Ⅰ curve. Types of time signal intensity curve were different significantly between two groups （χ^2=15.88, P=0.000）. Conclusion Residual disease of breast cancer after NACT enhanced in a reduced speed and decreased blood flow. Time signal intensity curve tend to change from type Ⅲ/Ⅱ to type Ⅰ.