奥野 敏隆¹, 毛利 衣子², 東 貞之², 内田 浩也²

Toshitaka OKUNO¹, Kinuko MORI², Sadayuki AZUMA², Hiroya UCHIDA²

¹西神戸医療センター外科, ²西神戸医療センター臨床検査技術部

¹Department of Surgery, Nishi-Kobe Medical Center, ²Department of Clinical Laboratory, Nishi-Kobe Medical Center

キーワード : breast cancer, Doppler ultrasound, pulsatility index, resistance index

超音波ドプラ法で得られるpulsatility index (PI), resistance index (RI)の乳癌と良性乳腺腫瘤の鑑別診断における有用性を検討した. 乳腺腫瘤474例に対して超音波ドプラ法を行い, 289腫瘤 (乳癌184例, 良性乳腺腫瘤105例)に対して血流波形分析が可能であった. 腫瘤の大きさは乳癌2.4±1.0 (平均±標準偏差)cm, 良性腫瘤が2.3±1.6 cmであった. 乳癌と良性腫瘤の大きさに有意差を認めなかった. PIは乳癌1.73±0.55, 良性腫瘤1.15±0.36であった. RIは乳癌0.80±0.10, 良性腫瘤0.68±0.10であった. PI, RIともに乳癌において良性腫瘤よりも有意に大きい値を示した. ROC曲線 (receiver operator characteristic curve)を用いた解析では, 最適なcutoff値としてPIでは1.3, RIでは0.74が得られた. しかし両グループでオーバーラップする部分が大きく, 各々の症例を確定的に癌か良性かの判別が可能なものではなかった. しかし, Bモード超音波診断と相補的に用いることで臨床的に有用と考える.

We evaluated the usefulness of the pulsatility and resistance indices derived from pulsed Doppler ultrasound data in differentiating malignant and benign breast tumors. We used Doppler ultrasound to examine 474 patients with breast tumors and analyzed the arterial waveform of 289 tumors, of which 184 were malignant and 105 were benign. The malignant breast tumors averaged 2.4賊1.0 (mean賊SD) cm in diameter; and the benign tumors averaged 2.3賊1.6 cm in diameter. Difference in the size of the tumors in the malignant and benign tumor groups was not statistically significant. The pulsatility indices of breast cancers and benign tumors averaged 1.73賊0.55 and 1.15賊0.36, respectively, and the resistance indices of breast cancers and benign tumors averaged 0.80賊0.10 and 0.68賊0.10, respectively. Both the pulsatility and resistance indices of the breast cancer group were significantly larger than those of the benign tumor group. We used the receiver operator characteristic curve to determine the most appropriate cutoff values for discriminating breast cancers from benign tumors: They were 1.3 on the pulsalility index and 0.74 on the resistance index. Because of the considerable overlap in the ranges of the pulsatility and resistance indices, individual values were not reliable for differentiation in individual cases. When used in conjunction with grayscale imaging, however, these values may prove to be helpful diagnostic parameters.