Brightness analysis in contrast-enhanced ultrasound using sonazoid for breast cancer.

Abstract

e22113 Background: We evaluated the contrast effects of Sonazoid in tumor tissue according to brightness intensity, in cases pathologically diagnosed with breast cancer. Methods: Six cases of ductal carcinoma in situ (DCIS) and seven cases of invasive ductal carcinoma (IDC) diagnosed with needle or Mammotome biopsy between September and December 2012 were examined. The mean ages of the DCIS and IDC cases were 51.7 ± 11.8 years and 62.5 ± 15.7 years respectively. In the IDC cases, tumor diameter was 6-10 mm in three cases, 11-20 mm in three cases and over 50 mm in one case. Two IDC cases were of the luminal A subtype, three cases were luminal B and two cases were triple negative. The ultrasound equipment used was HI VISION ASCENDUS (Hitachi Medical Corporation). The contrast agent, Sonazoid, was administered intravenously at 0.01ml/kg, and for approximately 50 seconds, the tumor sections were fixated and underwent imaging. Sonazoid brightness in the tumor was digitized and a time intensity curve was created based on brightness intensity and time changes. Early and peak contrast brightness was then compared in order to objectively examine changes in contrast effects. Results: Peak brightness was 1.6 ± 0.3 times and 4.8 ± 3.2 times the early brightness in DCIS and IDC cases respectively, indicating a more significant increase in IDC cases (P < 0.05). Comparison according to subtype in IDC cases also revealed a strong increasing trend in triple negative cases, with results showing that peak brightness compared to early brightness was 9.1 times greater in triple negative cases, 2.7 times greater in luminal A cases and 3.3 times greater in luminal B cases. Classification of IDC cases according to nuclear grade (NG) found that peak brightness was 6.2 times greater than early brightness in NG3 cases, 5.7 times greater in NG2 cases and 1.7 times greater in NG1 cases. Conclusions: Brightness intensity, when digitized and analyzed, could be applied to the differential diagnosis of DCIS and IDC. Brightness intensity may also exhibit correlations with subtypes and NG, suggesting that it could be applied to malignancy grading, as well as the prediction of effects of drug therapy and effect measurement.