Development of sentinel node targeting technique in breast cancer patients

The goals of this clinical study were to develop a clinically relevant technique of targeting the sentinel lymph nodes for surgical removal in breast cancer patients and to determine the accuracy of the sentinel node for predicting whether regional metastases have occurred. One hundred fifty-seven patients with breast cancer and clinically negative lymph nodes had 0.2 to 1.0 mCi of a radiopharmaceutical injected into the breast around the primary cancer. All patients underwent completion lymphadenectomy immediately following sentinel node resection. The nodes were analyzed pathologically to determine which nodes contained metastases. A considerable variation was observed in the ability of different radiopharmaceutical agents to selectively label the sentinel node. Of those evaluated, 1 mCi technetium sulfur colloid in a volume of 8 ml provided the best labeling rate (29/29 = 100%). Of 119 patients in which a sentinel node was identified, 41 had pathologically positive nodes and in only two cases was the sentinel node not one of the pathologically positive nodes (false-negative rate 4.9%). The mean number of sentinel nodes was three. There was considerable variation in the ability of lymphoscintigraphic agents to selectively label the sentinel lymph node in breast cancer agents. Technetium sulfur colloid appears to successfully label the sentinel nodes in >90% breast cancer patients and was the best agent of the group evaluated. The pathology of the sentinel lymph node has a high accuracy for predicting whether regional lymph node metastases have occurred.