弥散加权磁共振成像：预测乳腺癌患者新辅助化疗反应的预处理。

Diffusion-weighted MR imaging: pretreatment prediction of response to neoadjuvant chemotherapy in patients with breast cancer.

机构信息

Department of Radiology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Republic of Korea.

出版信息

Radiology. 2010 Oct;257(1):56-63. doi: 10.1148/radiol.10092021.

DOI:10.1148/radiol.10092021

PMID:20851939

Abstract

PURPOSE

To evaluate the potential of diffusion-weighted (DW) magnetic resonance (MR) imaging with an apparent diffusion coefficient (ADC) map in the prediction of response to neoadjuvant chemotherapy in patients with breast cancer.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board, which waived the informed consent requirement. Fifty-three consecutive women (mean age, 43.7 years; median age, 42.0 years; age range, 24-65 years) with 53 invasive breast cancers (mean diameter, 5.0 cm; median diameter, 4.2 cm; diameter range, 2.0-13.3 cm) who had undergone chemotherapy were included. Both DW MR imaging (b values, 0 and 750 sec/mm(2)) and dynamic contrast material-enhanced (DCE) MR imaging were performed at 1.5 T before and after chemotherapy prior to surgery. Mean time from initiation of chemotherapy to posttreatment ADC measurement was 54 days (range, 48-62 days). Average ADC for three regions of interest per tumor on ADC maps was calculated. Patients with a reduction in tumor diameter of at least 30% after chemotherapy at DCE MR imaging were defined as responders. Pretreatment ADCs and percentage increases in ADC after chemotherapy in responders and nonresponders were compared. The best pretreatment ADC cutoff with which to differentiate between responders and nonresponders was calculated with receiver operating characteristic curve analysis.

RESULTS

After chemotherapy, 36 (68%) patients were classified as responders, and 17 (32%) were classified as nonresponders. Pretreatment mean ADC ([1.036 ± 0.015] × 10(-3) mm(2)/sec [standard error]) of responders was significantly lower than that of nonresponders ([1.299 ± 0.079] × 10(-3) mm(2)/sec) (P = .004). Furthermore, mean percentage ADC increase of responders (47.9% ± 4.8) was higher than that of nonresponders (18.1% ± 4.5) (P < .001). The best pretreatment ADC cutoff with which to differentiate between responders and nonresponders was 1.17 × 10(-3) mm(2)/sec, which yielded a sensitivity of 94% (95% confidence interval [CI]: 81%, 99%) and a specificity of 71% (95% CI: 44%, 90%).

CONCLUSION

Patients with breast cancer and a low pretreatment ADC tended to respond better to chemotherapy. Prediction of response to neoadjuvant chemotherapy with DW MR imaging might help physicians individualize treatments and avoid ineffective chemotherapy.

摘要

目的

评估扩散加权（DW）磁共振成像（MR）与表观扩散系数（ADC）图在预测乳腺癌新辅助化疗反应中的潜在价值。

材料与方法

本回顾性研究经机构审查委员会批准，豁免了知情同意要求。共纳入 53 例连续接受化疗的浸润性乳腺癌女性患者（平均年龄 43.7 岁；中位年龄 42.0 岁；年龄范围 24-65 岁），共 53 个病灶（平均直径 5.0 cm；中位直径 4.2 cm；直径范围 2.0-13.3 cm）。所有患者在术前均接受了 1.5 T 下的 DW MR 成像（b 值分别为 0 和 750 sec/mm2）和动态对比增强（DCE）MR 成像检查。从化疗开始到治疗后 ADC 测量的平均时间为 54 天（范围 48-62 天）。在 ADC 图上对每个肿瘤的三个感兴趣区进行平均 ADC 计算。根据 DCE MR 成像，肿瘤直径缩小至少 30%的患者被定义为化疗有效。比较化疗有效者和无效者的肿瘤治疗前 ADC 值和化疗后 ADC 值的变化率。通过受试者工作特征曲线分析计算预测化疗有效与无效的最佳肿瘤治疗前 ADC 值截断值。

结果

化疗后，36 例（68%）患者被归类为化疗有效者，17 例（32%）为化疗无效者。化疗有效者的肿瘤治疗前平均 ADC 值[1.036±0.015]×10(-3)mm2/sec（标准误差）显著低于化疗无效者[1.299±0.079]×10(-3)mm2/sec（P=0.004）。此外，化疗有效者的平均 ADC 值变化率（47.9%±4.8）高于化疗无效者（18.1%±4.5）（P<0.001）。预测化疗有效与无效的最佳肿瘤治疗前 ADC 值截断值为 1.17×10(-3)mm2/sec，其诊断效能为敏感性 94%（95%置信区间：81%，99%），特异性 71%（95%置信区间：44%，90%）。