Sentinel Node Biopsy in Breast Cancer Using a Gamma-detection Probe

Kim, Sung Won; Kang, Hee Joon; Chung, Ki Wook; Kim, Hee Joung; Ko, Chang Dae; Youn, Yeo Kyu; Oh, Seung Keun; Choe, Kuk Jin; Noh, Dong Young

Abstract

PURPOSE
Sentinel lymph node (SLN) biopsy has emerged as a substitute for a conventional axillary lymph node (ALN) dissection in early breast carcinomas. We evaluated SLN biopsy in breast carcinoma using a gamma-detection probe in order to identify its accuracy as a staging procedure for lymph node status.
METHODS
Fifty-one patients with breast carcinomas who underwent a SLN biopsy followed by an ALN dissection between June 1999 and January 2001 were evaluated. Tc 99m antimony trisulfide colloid was used as a tracer and SLN biopsy using a gamma-detection probe was done following breast lymphoscintigraphy. Intraoperative imprint cytology (II C) was done for each SLN. If a SLN biopsy was free of metastasis by permanent hematoxylin and eosin (H&E) staining, immun ohistochemical (IHC) staining using pan-cytokeratin was do ne to detect micrometastasis.
RESULTS
ALN metastases were identified in 21.6% of pa tients and the resection rate of SLN was 94.1%. The mean number of resected SLN was 1.8, all located at the axilla. IIC had a sensitivity of 72.7% and a spe cificity of 100%. The false-negative rate of SLN biopsy was 12.5% when SLNs were evaluated by H&E staining alone. However, the false-negative rate improved up to 0% when IHC staining was added.
CONCLUSION
SLN biopsy using a gamma-detection probe proved to be a very sensitive method to detect SLN in breast carcinoma patients. Frozen biopsy should be added to im prove the outcomes of intraoperative examination of SLN. If permanent biopsy revealed that SLN was free of tumorthe by H&E staining, IHC staining should be done to improve false-negative rate of SLN biopsy.