SURGICAL RESECTION AND RADIOLOCALIZATION OF THE SENTINEL LYMPH-NODE IN BREAST-CANCER USING A GAMMA-PROBE

We have recently reported on a technique of gamma probe localization o f radiolabelled lymph nodes to identify the sentinel node in malignant melanoma. In order to determine whether this technique is applicable to assist in staging breast cancer, a pilot study was begun to address two questions: (i) can the sentinel lymph node draining a breast canc er be identified for selective resection; and (ii) is the sentinel lym ph node predictive of the status of the entire axillary lymph nodes? O ne to four hours prior to axillary lymph node dissection, 22 consecuti ve patients had approximately 0.4 mCi of technetium sulfur colloid in 0.5 ml saline injected around the perimeter of the breast lesion. A ha nd-held gamma counter was used at surgery to locate the lymph node(s) receiving drainage from the breast. A sentinel lymph node was identifi ed in 18 of 22 patients. Of these 18 patients, the sentinel lymph node was positive in seven of seven patients, with pathologically verified metastatic breast cancer to at least one lymph node. In three out of seven patients, the sentinel lymph node was the only lymph node with m etastatic cancer. In this pilot study of breast cancer patients, we co nclude that: (i) radiolocalization and selective resection of sentinel lymph nodes is possible; and (ii) the sentinel lymph node appears to predict correctly the status of the remaining axilla. These data justi fy a larger clinical trial to verify the value of this technique.