Sensitivity of axillary specimen x-ray to predict nodal count and positivity

Background: The number of examined axillary lymph nodes (ALN) has been proposed as an indicator of prognosis along with quality and adequacy in breast cancer surgery. The purpose of this study was to examine the utility of imaging axillary specimens with x-ray (lymphogram) to determine the number of lymph nodes. We sought to determine the sensitivity and specificity of a lymphogram in identifying nodal positivity. Methods: Patients who underwent sentinel lymph node (SLN) and axillary lymph node dissections (ALND) were prospectively accrued to this double-blinded, single-institution trial from December 2009 to January 2011. A single physician interpreted all lymphograms for the number of ALNs and positivity determined by size, spiculations, irregularities, and calcifications. Results: Twenty female (age 50.8 ± 14.3 years) patients were accrued to the study. The lymphogram located more lymph nodes compared with pathology in 11 of 16 cases (68.8%). In these 11 cases, lymphogram identified 170 nodes and the pathologist located 132 (77.6%). Of the 16 ALND specimens, 6 were from patients naive to chemotherapy and averaged 13.8 ± 6.6 nodes;10 were from neoadjuvant chemotherapy patients and had an average number of 14.9 ± 7.4 nodes. In neoadjuvant chemotherapy patients, sensitivity of the lymphogram to detect nodal positivity was 91.7% and specificity was 33.3%. Conclusions: This study demonstrated that lymphogram accurately identifies nodal count. This can be used for documentation of an adequate ALND for reimbursement. Furthermore, there may be potential value of lymphogram in intraoperative determination of nodal positivity.