Feasability of contrast-enhanced CT in breast conservation surgery for invasive and non-invasive breast cancer.

Abstract

e12084 Background: MRI imaging has become the standard for planning breast conservation surgery for breast cancer. However, due partly to lack of resources of a small clinic practice, we have been utilizing contrast enhanced CT facilitated with ultrasound for this purpose. The aim of this presentation is to assess the feasability of contrast-enhanced CT in breast conservation surgery. Methods: We used GE Brightspeed-8 CT, with HP Z440 workstation (for free line masking). 100 mld of Iopamidol contrast medium was injected at a rate of 3 ml/sec and image capture was done at the 60 or 180 second phase. Images were taken with the patient in a supine position. We evaluate a total of 2057 cases operated in a ten year period between 2005.1.1 to 2014.12.31, excluding cases receiving preoperative chemotherapy. 1,757 cases (85%) were invasive and 300 cases (15%) were non-invasive breast cancer cases. Results: Lesion localization by contrast-enhance CT was acceptable by predefined criteria in 72% of invasive carcinoma cases, and 89% non-invasive carcinoma cases. The breast conservation rate was 77% and 83% for invasive and non-invasive breast cancer cases, respectively. Surgical margins were positive “on ink” for 8 cases (0.6%), and positive within 5 mm (including DCIS) in 340 cases (25.1%) of the 1,357 invasive cancer cases treated with BCT. There were 7 completion total mastectomies and 3 partial mastectomies for the patients with positive margins (11/340 = 3.2%). Surgical margins were positive for 78 cases (31.3%) of the 249 DCIS cases undergoing BCT. There was 1 completion mastectomy and 2 partial mastectomies for the patients with positive margins (3/78 = 3.8%). Local recurrence rates for invasive and non-invasive breast cancer cases undergoing BCT were 2.6% (average observation period 65.0 months) and 2.8% (average observation period 64.4 months), respectively. Conclusions: Contrast-enhanced CT facilitated with ultrasound imaging is an effective and easy to implement modality for planning breast conservation surgery in invasive and non-invasive breast cancer, possibly in part due to imaging that corresponds closely to the breast position during surgery.