Blue dye versus combined blue dye—radioactive tracer technique in detection of sentinel lymph node in breast cancer

Background Sentinel lymph node biopsy in breast cancer can be used to select patients in which axillary lymph node dissection could be avoided. In this study we compared the value of two methods for identification of sentinel node (SN) using either only blue dye or combination of blue dye and radioactive tracer. Material and methods All patients were women with clinically T1−2N0M0 breast cancer. They were randomized into two groups. In Group A (50 patients) SN marking was performed only with blue dye and in Group B (100 patients) combined SN marking with blue dye and radiotracer was done. We used 2 ml of blue dye Patentblau V® (Byk Gulden). Radiotracer was Antimony sulfide marked with Tc 99m and of 0.3 mCy (11.1 MBq) activity. Application method of both contrasts was peritumoral. After SN biopsy all patients underwent mastectomy or conservative surgery with axillary lymph node dissection of levels I and II. Results In Group A mean of 1.7 SNs were identified (median 1, range 1–4). False-negative rate in this group was 3/17 (17.6%) with negative-predictive value 20/23 (86.9%), sensitivity 14/17 (82%), specificity 20/33 (60%) and accuracy 34/50 (68%). In Group B mean number of SNs excised per case was 1.6 (median 1, range 1–5). False-negative rate was 2/44 (4.5%), negative-predictive value 41/43 (95.3%), sensitivity 42/44 (95%), specificity 41/56 (73%) and accuracy 83/100 (83%). The combination technique was significantly superior to blue-dye alone technique for negative-predictive value (p=0.033) and overall accuracy (p=0.048). Conclusions The prediction of axillary lymph node status in breast cancer patients using combined technique has significantly higher accuracy than marking of SN with blue dye alone and therefore should be preferred.