Clinical Benefits of Multidetector-Row Computed Tomography for Detecting Contralateral Breast Cancer.
Authors: Nakano S. 
Published: December 2010

Abstract
Background: It is not uncommon that the use of multidetector-row computed tomography (MDCT) for assessing the intraductal spread of breast cancer results in the detection of enhancing lesion of the contralateral breast. We retrospectively evaluated whether MDCT could contribute to the early detection of contralateral breast cancer in women with a diagnosis of breast cancer and no suspicious lesions on mammogram or ultrasonogram of the contralateral breast.Methods: MDCT has been routinely used since 2004 to assess the intraductal spread of breast cancer in women who are scheduled for breast conserving surgery at our institution. A total of 518 women with newly diagnosed unilateral breast cancer who had no allergy to contrast material and were candidates for breast conserving surgery underwent MDCT at our institution between January 2004 and April 2009. MDCT was performed using a 16-detector row MDCT scanner set for 2mm collimation, 120 kVp and 180mA. Axial images of the contralateral breast were obtained for evaluation.Results: Of the 518 women with breast cancer, previous contralateral mastectomy in 13 cases, post primary chemotherapy in 43 cases, and ipsilateral breast recurrence in 2 cases, plus one case of male breast cancer were subsequently determined to be ineligible. Thus 459 women were eligible for participation in this study. The mean age was 56.9 years.Clinical stage 0 to II of index breast cancer accounted for 95.9% of patients.There were 168 premenopausal patients and 291 postmenopausal patients. Of 459 lesions, the histological diagnosis of index cancer was ductal carcinoma in situ in 56, invasive ductal carcinoma in 363, invasive lobular carcinoma in 14, and other in 26. Among 36 women with enhancing breast lesions, there were malignant suspected lesions on mammogram and ultrasonogram in 15, and suspicious lesions on only MDCT images in 21. Targeted ultrasonography was performed in suspicious lesions identified by MDCT for cytological or pathological biopsy, and all lesions were detected by targeted ultrasonography.The maximum diameter of suspicious lesions detected only with MDCT was under 5.0 mm in 10 lesions, 5.1-10.0 mm in 9 lesions, 10.1-15.0mm in one lesion, and over 15.1 mm in one lesion. Ultrasound-guided fine needle aspiration was performed in 11 women, and a histological diagnosis was made in 17 women. We performed ultrasound-guided vacuum-assisted biopsy and incisional biopsy in 14 and 3 women, respectively. There were 6 benign and 11 malignant tumors. MDCT contributed to the diagnosis of contralateral occult breast cancer in 12 women (2.6%), including one with a suspicious lesion by fine needle aspiration and in whom breast cancer was later diagnosed at another institution.Conclusions: In this study, MDCT contributed to the diagnosis of contralateral occult breast cancer.Women with breast cancer have an increased risk of developing a second breast cancer. MDCT has a potential role in detecting contralateral breast cancer in women who are at high risk for such cancer.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5022.