18F-FDG PET/CT融合显像对乳腺癌新辅助化疗疗效的预测价值

背景与目的:既往研究表明,18F-FDG PET显像结果与肿瘤新辅助治疗后的临床或病理反应密切相关.本研究拟探讨乳腺癌新辅助化疗前后18F-FDGPET/CT融合显像与细胞凋亡间的关系,以求进一步明确PET/CT对乳腺癌新辅助化疗疗效的预测价值.方法:45例原发性乳腺癌患者细针穿刺确诊后给予新辅助化疗三个周期,新辅助化疗前后行PET/CT融合显像检查并计算肿瘤区与非肿瘤区放射性比值(tumor to non-tumor activity ratio,T/N),dTUP末端标记技术检测穿刺及手术标本的癌细胞凋亡指数(apoptotic index,AI).结果:新辅助化疗后临床疗效评价完全缓解4例(8.9%),部分缓解29例(64.4%),疾病稳定10例(22.2%),疾病进展2例(4.4%).化疗前后肿瘤平均T/N值分别为3.23±0.63、2.31±0.49(P=0.006),下降6.4%～50.8%.化疗前后AI分别为(2.81±0.76)%、(17.31±6.85)%(P＜0.001),增高1.9%～41.3%.T/N值下降率与AI变化值间存在直线相关关系(r(.)=0.850,P＜0.001).以化疗后T/N值下降≥20%为阈值,PET/CT预测肿瘤临床缓解的灵敏度、特异度分别为90.9%、83.3%,阳性、阴性预测值分别为93.8%、76.9%,准确率为92.1%.结论:18F-FDG PET/CT融合显像与乳腺癌新辅助化疗后的细胞凋亡状态密切相关,对预测化疗疗效具有一定的应用价值.

Value of fused 18F-FDG PET/CT images in predicting efficacy of neoadjuvant chemotherapy on breast cancer

BACKGROUND & OBJECTIVE: Previous studies confirmed that fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) imaging relates to clinical or pathologic responses of tumors to neoadjuvant therapy. This study was to evaluate the correlation of fused 18F-FDG PET/CT images to cell apoptosis of breast cancer after neoadjuvant chemotherapy, and explore its value in predicting the efficacy of neoadjuvant chemotherapy on breast cancer. METHODS: Forty-five patients with primary breast cancer, proven by core needle biopsy, underwent 3 cycles of neoadjuvant chemotherapy. PET/CT was performed before and after treatment, and the ratio of tumor area activity to non-tumor area activity (T/N) was calculated. The apoptosis index (AI) was determined using TUNEL technique. RESULTS: Of the 45 patients, 4(8.9%) achieved complete remission (CR), 29 (64.4%) achieved partial remission (PR), 10 (22.2%) presented stable disease (SD), and 2 (4.4%) presented progressive disease (PD) after neoadjuvant chemotherapy. The mean T/N ratio was decreased from 3.23+/-0.63 before chemotherapy to 2.31+/-0.49 after chemotherapy (P=0.006) by 6.4%-50.8%. The mean AI was increased from (2.81+/-0.76)% before chemotherapy to (17.31+/-6.85)% after chemotherapy (P<0.001) by 1.9%-41.3%. The T/N ratio reduction rate was positively correlated to AI change (r(s)=0.850, P<0.001). At a threshold of 20% decrease from baseline in T/N ratio, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET/CT in predicting clinical response were 90.9%, 83.3%, 93.8%, 76.9%, and 92.1%, respectively. CONCLUSIONS: Neoadjuvant chemotherapy might effectively induce cell apoptosis in breast cancer and inhibit the glucose uptake. Fused PET/CT imaging is closely related to cell apoptosis status of breast cancer after neoadjuvant chemotherapy, and may be applied to predict the response of breast cancer to neoadjuvant chemotherapy.