The external and internal radioimmunodetection of metastatic lymph nodes in breast cancer

A radiolabeled monoclonal antibody （McAb） 6c6 was used to detect the metastatic lymph nodes of breast cancer externally and internally. In-111 was labeled to 6c6 by DTPA method. Iodogen method was used to label I-131. Hosted tumor in nude mouse model could be demonstrated by both isotopes labeled 6c6 with external gamma imaging. The radiolabeled 6c6 was injected into the web space of esch in seven women with breast cancer and one with benign breast tumor. The scans were positive in two axillae with palpable nodes and four with impalpable nodes. Pathologic examination later confirmed metastases in five of the axillae. Two axillae, one of which with palpable nodes, showed negative result, and here no tumor cells were found by pathologists.
Intraoperative metastatic lymph node detection with a hand-held gamma probe was carried out in six patients. 24 lymph nodes were measured with 17%（1/6） false negative and no false positive result （0/18）, indicating that the result detected by the hand-held gamma probe presents the real radioactivity of the tissues examined. There were 60 lymph nodes that were removed and detected again by well shape detector after operation. The false positive rate was 14%（6/42）, and the false negative rate was 11%（2/18）, indicating that the radiolabeled McAb 6c6 could specifically combine with the metastatic lymph nodes of breast cancer in vivo.