Radiolabeled Sentinel Node Biopsy: Collaborative Trial with the National Cancer Institute

Abstract

The objective of this study was to maximize the success rate of sentinel node (SN) localization in breast cancer patients with the tracer that demonstrated the highest initial success during a preliminary evaluation. Altogether, 145 patients with operable invasive breast cancer and clinically negative lymph nodes were studied. Technetium 99m (99mTc)-sulfur colloid was injected into the breast parenchyma surrounding the invasive cancer or the biopsy cavity. Variable volumes of tracer, amounts of 99mTc, and duration of time between injection and surgery were evaluated. A hand-held gamma detector was used at surgery to locate and guide resection of all radioactive sentinel nodes (SNs), including those that were extraaxillary. A conventional lymphadenectomy was then performed in all cases. Based on previous studies, unfiltered sulfur colloid provided a higher success rate of SN identification than the other tracer types. Further evaluation with 99mTc-sulfur colloid demonstrated that increased volume increased the success rate of SN identification. An injection volume of 8 ml resulted in a success rate of 98%. SNs were not exclusively located in the axilla: In 8.6% of cases SNs were removed from an internal mammary location. The overall accuracy of patients with SNs resected was 98.4%, and the false-negative rate was 4.4%. It was concluded that (1) unfiltered 99mTc-sulfur colloid at a volume of 8 ml resulted in a high success rate for SN identification; (2) a significant number of the SNs were extraaxillary in location; and (3) the accuracy of the SNs for determining whether regional metastases had occurred was high. The U.S. National Cancer Institute is funding a randomized phase III clinical trial to evaluate SN resection compared to conventional axillary lymphadenectomy in clinical node-negative breast cancer patients. Major endpoints of this trial include long-term regional control and survival.

Immunohistochemically detected tumor cells in the sentinel lymph nodes of patients with breast carcinoma

“…This heterogeneity among micrometastases will confound the interpretation of clinical trials, two of which currently aim to resolve the significance of IHC-detected micrometastases by blinding both patient and clinician to the results of IHC staining. 23,24 Some argue that IHC-detected micrometastases may not be metastases at all. Rosser 8 has suggested that manipulation of the breast either during mammography or at surgery could mechanically disperse tumor cells and that such manipulation explains the IHC-positive SLN.…”

“…Pending the results of clinical trials currently in progress, 23,24 the treatment of patients with an IHC-positive SLN will remain a matter of clinical judgment, balancing proven evidence, uncertain evidence, and the preferences of the patient. As we stand on the threshold of molecular profiling of breast carcinoma, 30,31 our understanding of this heterogeneous disease remains a tantalizing mixture of both mechanistic and biologic considerations.…”

Cytokeratin‐positive cells in sentinel lymph nodes in breast cancer are not random events

“…[25][26][27] The strength of these observations awaits the results of clinical trials currently in progress. 28,29 Until then, the clinical significance of IHC-detected cells in the SLNs of patients with breast carcinoma will remain a matter of debate.…”

Lymphoscintigraphy in the Sentinel Lymph Node Technique for Breast Tumor: Value of Early and Late Images for the Learning Curve

“…Most authors consider that the intratumoral site is unreliable because of possible tracer sequestration. The other injection modes have all provided excellent results, and no truly comparative studies have been conducted to show that one of these sites is preferable [12][13][14].…”