Radio-guided sentinel lymph node biopsy using periareolar injection technique for patients with early breast cancer

Sentinel lymph node (LN) biopsy has been widely adopted in the axillary staging of clinical node-negative breast cancer patients. This study aimed to evaluate the accuracy of radio-guided sentinel LN (SLN) biopsy (SLNB) using the periareolar injection technique for predicting the histopathologic status of axillary LNs in early breast cancer patients.

Between November 2003 and November 2004 in the National Taiwan University Hospital, radio-guided SLNB using the periareolar injection technique was consecutively performed in 213 female patients with early breast cancer (stage T1 and T2) but without clinically palpable axillary LN and previous chemotherapy. Two mCi of filtered (0.22 microm) (99m)Tc-sulfur colloid were injected in the afternoon 1 day before surgery (2-day protocol) or 1 mCi of the same radiopharmaceutical was injected on the morning of the surgery (1-day protocol). During surgery, a handheld gamma probe was used to identify the LNs with radioactivity in the axilla. A node was deemed a SLN if its radioactivity was >10% of the hottest node. All the SLNs identified were removed for histology.

Radioactive SLN was identified at surgery in 207 patients. The SLN identification rate was 97.2% (207/213). Of these 207 patients, 163 patients had received both SLNB and axillary LN dissection. Among these 163 patients, 77 patients had LN metastases and four had negative SLN but positive non-SLN. The false-negative rate of SLNB for the detection of axillary LN metastases was 5.2% (4/77). There were no statistical differences between false-negative and SLN positive groups for all factors.

Our study suggests that SLNB with periareolar injection of radiocolloid provides valuable information on the axillary nodal status in patients with early breast cancer.