Gamma probe and ultrasonographically-guided fine-needle aspiration biopsy of sentinel lymph nodes in breast cancer patients

Aim The purpose of the present study was to evaluate the usefulness of gamma probe and ultrasonographically-guided fine-needle aspiration biopsy (FNAB) in the pre-operative detection of sentinel node (SN) metastasis in breast cancer patients. Methods Sentinel node biopsy (SNB) was performed in patients with stage I or II breast cancer with clinically negative nodes using dye and radio-isotope. Axillas of 60 patients in whom a hot spot was detected by gamma probe were examined by ultrasonography. Pre-operative diagnosis of SN metastasis by gamma probe and ultrasonographically-guided FNAB was compared with the histological results of SN. Results The sensitivity, specificity and overall accuracy of ultrasonography in the diagnosis of SN metastasis were 50.0%, 92.1% and 76.7%, respectively. SNs were visualized by ultrasonography in 29 of 60 patients. Of 14 patients with positive results by ultrasonography, four had positive and two had negative cytology. The combination of ultrasonography and ultrasonographically-guided FNAB for visualized nodes had a sensitivity of 78.5%, specificity of 93.3% and overall accuracy of 86.2%. Blind FNAB in the hot spot was not useful in the detection of SN metastasis in patients whose SNs failed to be detected by ultrasonography. Conclusions Gamma probe and ultrasonographically-guided FNAB is a potentially useful method for pre-operative detection of SN metastasis. In patients with positive SNs, SNB is not indicated and complete axillary lymph-node dissection can be performed as a primary procedure.