Purpose: To evaluate the clinical usefulness of multislice helical CT (MSCT) for assessing breast cancer extent.
Materials and methods: MSCT was performed in 70 patients with Tis/T1 breast cancer [12 ductal carcinoma in situ (DCIS) and 58 invasive carcinoma]. The distribution pattern of contrast enhancement (CE) was classified into five categories: solitary lesion (localized area of CE), grouped lesion (satellite: localized CE with linear and/or spotty enhancement; crowded: clustered spotty enhancement), separated lesion (multifocal foci of CE), mixed lesion (grouped lesion with multifocal foci), and diffuse lesion (diffuse CE).
Results: Solitary lesion was seen in five cases of DCIS, 27 invasive carcinomas without intraductal spread (IDS), six invasive carcinomas with IDS, and one multicentric cancer. Grouped lesion was seen in six DCIS and 15 invasive carcinomas with IDS. Separated lesion was seen in one case of invasive carcinoma and fibroadenoma, and three multifocal/multicentric cancers. Mixed lesion was seen in two multicentric cancers. Diffuse lesion was seen in one case of DCIS and three invasive carcinomas. The coincident rate between MSCT pattern and histologic distribution was 85.7% (60/70). In solitary and grouped lesions, accuracy for the detection of tumor extent with a deviation of less than 2 cm in length was 91.7% (55/60).
Conclusion: MSCT is extremely accurate in the diagnosis of IDS and the multicentricity of breast cancer.