Department of Radiology, Korea University Anam Hospital, Korea University College of Medicine.
Department of Radiology, Korea University Guro Hospital, Korea University College of Medicine, Seoul.
Invest Radiol. 2019 May;54(5):273-281. doi: 10.1097/RLI.0000000000000538.
The aim of this study was to investigate the feasibility of using low-dose perfusion computed tomography (CT) in breast cancers for quantification of tumor vascularity and to correlate perfusion indexes with prognostic biomarkers.
This preliminary study was approved by our institutional review board. Signed informed consent was obtained from all 70 enrolled patients with invasive breast cancers. Low-dose perfusion CT was performed with the patient in the prone position using a spectral CT device set at 80 kVp and 30 mAs (1.30-1.40 mSv). Images were analyzed using commercial software applying the maximum slope algorithm. On CT perfusion maps, perfusion (mL/min per 100 mL), blood volume (mL/100 g), time-to-peak enhancement (second), and peak enhancement intensity (HU) were measured in the tumor, normal breast glandular tissues, and fat. Tumor grade, estrogen receptor (ER), human epidermal growth factor receptor 2 (HER2), and Ki67 level were evaluated using histopathology. Statistically, CT perfusion indexes of the tumor and normal glandular tissues or fat were compared using the Wilcoxon signed-rank test, and CT indexes were correlated with histological characteristics using the Mann-Whitney U or Kruskal-Wallis tests. We also correlated CT indexes with magnetic resonance imaging enhancement characteristics.
In breast cancers, perfusion, blood volume, and peak enhancement intensity values were significantly higher, and time to peak was shorter than in normal glandular tissues and fat (P < 0.001). Perfusion increased significantly in high-grade, ER-, or HER2+ cancers (P < 0.05). Time to peak decreased in ER-, HER2+, and high-grade cancers or in those with high Ki67 levels (P < 0.05). Peak enhancement intensity significantly increased in high-grade cancers (P < 0.05). HER2 overexpressing cancers showed significantly higher perfusion and shorter time to peak than luminal-type cancers (P < 0.05). Perfusion increased and time to peak decreased significantly in cancers with washout enhancement patterns on magnetic resonance imaging.
Low-dose perfusion CT in the prone position is feasible to quantify tumor vascularity in breast cancers, and CT perfusion indexes are significantly correlated with prognostic biomarkers and molecular subtypes of breast cancer.
本研究旨在探讨低剂量灌注 CT 在乳腺癌中的可行性，以定量评估肿瘤血管生成，并将灌注指标与预后生物标志物相关联。
本初步研究获得了我们机构审查委员会的批准。所有 70 名患有浸润性乳腺癌的入组患者均签署了知情同意书。采用能谱 CT 设备以 80kVp 和 30mAs（1.30-1.40mSv）对患者行俯卧位低剂量灌注 CT。采用商业软件应用最大斜率算法对图像进行分析。在 CT 灌注图上，在肿瘤、正常乳腺腺体组织和脂肪中测量灌注（mL/min/100mL）、血容量（mL/100g）、达峰时间（秒）和达峰增强强度（HU）。采用组织病理学评估肿瘤分级、雌激素受体（ER）、人表皮生长因子受体 2（HER2）和 Ki67 水平。采用 Wilcoxon 符号秩检验比较肿瘤和正常腺体组织或脂肪的 CT 灌注指标，采用 Mann-Whitney U 或 Kruskal-Wallis 检验比较 CT 指标与组织学特征的相关性。我们还将 CT 指标与磁共振增强特征进行了相关性分析。
在乳腺癌中，与正常腺体组织和脂肪相比，灌注、血容量和达峰增强强度值明显更高，达峰时间更短（P<0.001）。高级别、ER-或 HER2+癌症的灌注明显增加（P<0.05）。ER-、HER2+、高级别或 Ki67 水平高的癌症的达峰时间缩短（P<0.05）。高级别癌症的达峰增强强度明显增加（P<0.05）。HER2 过表达的癌症的灌注和达峰时间明显短于 luminal 型癌症（P<0.05）。磁共振成像呈洗脱增强模式的癌症的灌注增加，达峰时间缩短。
俯卧位低剂量灌注 CT 可用于定量评估乳腺癌的肿瘤血管生成，CT 灌注指标与乳腺癌的预后生物标志物和分子亚型显著相关。
