Sentinel lymph node detection using computed tomography lymphography is accurate after neoadjuvant chemotherapy for breast cancer

For breast cancer patients who have undergone neoadjuvant chemotherapy (NAC), a sentinel lymph node biopsy (SLNB) has not been recommended until recently. This is due to the possible lymph-flow interruption caused by fibrotic changes following chemotherapy and possible increases in false-negative cases. We investigated the changes in the lymph-flow and the detection of sentinel lymph nodes (SLNs) using computed tomography (CT) lymphography before and after NAC. We enrolled 53 patients with breast cancer who had undergone CT lymphography between May 2004 and April 2006. In total, 75 examinations were performed; 44 before NAC and 31 just after NAC. The CT lymphography procedures were approved by the medical ethics committee of our university. After a comprehensive explanation, written informed consent was obtained from all the patients, prior to enrollment in the study. Differences in changes in the lymph-flow, detection of SLNs, and changes in the number of detected SLNs were examined before and after NAC. Differences in the categoric variables were analyzed using the Chi-square test or Fisher's exact test. The identification rate (90.5%) of the SLNs following NAC was higher than the one before NAC (79.5%). However, no statistically significant difference was noted. No interruptions to the lymph-flow prevented the detection of SLNs by NAC. By performing CT lymphography before and after NAC, the interruption to the lymph-flow can be checked and the site of SLNs can be identified prior to surgery. We found that SLNB is recommended for breast cancer patients with or without NAC.