From the Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine.
Kyoto-Katsura Hospital.
Invest Radiol. 2021 Aug 1;56(8):501-508. doi: 10.1097/RLI.0000000000000766.
The aim of this study was to investigate the variation of apparent diffusion coefficient (ADC) values with diffusion time according to breast tumor type and prognostic biomarkers expression.
A total of 201 patients with known or suspected breast tumors were prospectively enrolled in this study, and 132 breast tumors (86 malignant and 46 benign) were analyzed. Diffusion-weighted imaging scans with 2 diffusion times were acquired on a clinical 3-T magnetic resonance imaging scanner using oscillating and pulsed diffusion-encoding gradients (effective diffusion times, 4.7 and 96.6 milliseconds) and b values of 0 and 700 s/mm2. Diagnostic performances to differentiate malignant and benign breast tumors for ADC values at short and long diffusion times (ADCshort and ADClong), ΔADC (the rate of change in ADC values with diffusion time), ADC0-1000 (ADC value from a standard protocol), and standard reading including dynamic contrast-enhanced magnetic resonance imaging (BI-RADS) were investigated. The correlations of ADCshort, ADClong, and ΔADC values with hormone receptor expression and breast cancer subtypes were also analyzed.
The ADC values were lower, and ΔADC was higher in malignant tumors compared with benign tumors. The specificity of ADC values at all diffusion times and ΔADC values for differentiating malignant and benign breast tumors was superior to that of BI-RADS (87.0%-95.7% vs 73.9%), whereas the sensitivity was inferior (87.2%-90.7% vs 100%). Lower ADCshort and ADC0-1000 in ER-positive compared with ER-negative cancers (false discovery rate [FDR]-adjusted P = 0.037 and 0.018, respectively) and lower ADCshort, ADClong, and ADC0-1000 in progesterone receptor-positive compared with progesterone receptor-negative cancers (FDR-adjusted P = 0.037, 0.036, and 0.018, respectively) were found. Ki-67-positive cancers had larger ΔADCs than Ki-67-negative cancers (FDR-adjusted P = 0.018).
The ADC values vary with different diffusion time and vary in correlation with molecular biomarkers, especially Ki-67. Those results suggest that the diffusion time, which should be reported, might be a useful parameter to consider for breast cancer management.
本研究旨在探讨根据乳腺肿瘤类型和预后生物标志物表达，表观扩散系数（ADC）值随扩散时间的变化。
本研究前瞻性纳入了 201 名已知或疑似患有乳腺肿瘤的患者，共分析了 132 个乳腺肿瘤（86 个恶性和 46 个良性）。在临床 3.0T 磁共振成像扫描仪上使用振荡和脉冲扩散编码梯度（有效扩散时间分别为 4.7 和 96.6 毫秒）和 0 和 700 s/mm2 的 b 值采集 2 个扩散时间的扩散加权成像扫描。研究了短扩散时间（ADCshort）和长扩散时间（ADClong）ADC 值、ΔADC（ADC 值随扩散时间的变化率）、ADC0-1000（标准方案的 ADC 值）和包括动态对比增强磁共振成像（BI-RADS）的标准读数的诊断性能，以区分恶性和良性乳腺肿瘤。还分析了 ADCshort、ADClong 和 ΔADC 值与激素受体表达和乳腺癌亚型的相关性。
与良性肿瘤相比，恶性肿瘤的 ADC 值较低，ΔADC 值较高。所有扩散时间的 ADC 值和 ΔADC 值区分恶性和良性乳腺肿瘤的特异性优于 BI-RADS（87.0%-95.7% vs 73.9%），而敏感性较低（87.2%-90.7% vs 100%）。与 ER 阴性癌症相比，ER 阳性癌症的 ADCshort 和 ADC0-1000 值较低（经 FDR 校正的 P 值分别为 0.037 和 0.018），与孕激素受体阴性癌症相比，孕激素受体阳性癌症的 ADCshort、ADClong 和 ADC0-1000 值较低（经 FDR 校正的 P 值分别为 0.037、0.036 和 0.018）。Ki-67 阳性癌症的 ΔADC 值大于 Ki-67 阴性癌症（经 FDR 校正的 P = 0.018）。
ADC 值随不同的扩散时间而变化，并与分子生物标志物相关，特别是 Ki-67。这些结果表明，应报告扩散时间，这可能是乳腺癌管理的一个有用参数。
