Nariya Cho MD, Presenter: Nothing to Disclose

Woo Kyung Moon MD, Abstract Co-Author: Nothing to Disclose

To evaluate the role of preoperative axillary US and US-guided intervention in patients with breast cancer who are candidates for SLNB.

During last 6 months, 243 consecutive breast cancer patients with clinically negative axillary lymph node (LN) underwent SLNB. Patients with neoadjuvant chemotherapy (n=12), DCIS (n=15), previous excision of primary tumor (n=18), and failed needle localization (n=7) were excluded. A total of 191 patients (aged 24-77, median 46 years) underwent preoperative US and US-guided needle localization of the LN with the thickest cortex, followed by intra-operative SLNB using radiotracer (Tc-99m-antimony sulfur colloid 0.5mCi). The correspondence of the localized LN and SLN identified by the radiotracer was recorded. They were separately submitted to and reported by pathologists. The localized LN was classified according to the cortical thickness on US as follows: grade 1 ≤1.5mm; 1.5mm 3.5 mm with intact fatty hilum; grade 5 > 3.5 mm with a loss of fatty hilum. Positive predictive value (PPV) according to the LN grading was calculated.

No radiotracer uptake was found in 4% (7/191) of the patients. Of these technical failure cases, all localized lymph nodes classified as grades 3 to 5 at US, proved to be positive metastasis. Ninety one % (168/184) of localized lymph nodes corresponded to the SLN. Overall accuracy of the SLN status was 96%, sensitivity 85%, specificity 100%, and false negative rate 5% (7/144) for 54 patients with LN metastases. In 2 cases of false negative result, localized lymph nodes were reported positive for metastasis. The PPV of the US LN grading was as follows; grade1: 7% (3/43), grade2: 14% (11/80), grade3: 48% (23/48), grade4: 70% (7/10), and grade5: 100% (10/10).

Preoperative axillary US and US-guided intervention can detect metastatic lymph nodes which cause technical failure (7/191) or false negative (2/191) result at SLNB.

Preoperative US and US-guided intervention has potential to reduce technical failure or false negative result of SLNB by detection of LN infiltrated with tumor cells interfering uptake of radiotracer

Cho, N, Moon, W, Preoperative Axillary Ultrasound (US) and US-guided Needle Localization in Patients with Breast Cancer Undergoing Sentinel Lymph Node Biopsy (SLNB).  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5016306.html