Isotope-guided surgery for nonpalpable breast cancer

The hook-wire technique is used to guide surgical excision of nonpalpable breast lesions. Recently, isotope has been used to guide the excision, and when sentinel node biopsy is performed during the same operation, the procedure is termed Sentinel Node and Occult Lesion Localization (SNOLL). We evaluated the use of this procedure for nonpalpable cancers in Chinese women.

Seventy-four patients underwent SNOLL before breast-conserving surgery. Intratumoral injection of sulfur colloid and lymphoscintigraphy (LSG) were performed. A gamma probe was used for resection planning and localization of the sentinel node (SN). Blue dye mapping was used in patients with negative LSG. Complete excision was defined as a tumor-free margin greater than 1 mm.

The primary breast lesion was successfully removed in 73 patients (99%). Complete excision was achieved in 61 patients (82%). Drainage to axilla was detected by LSG in 53 patients (72%). The gamma probe was more sensitive than LSG and had an 82% SN identification rate. Patients with a positive LSG had a higher chance of SN localization by gamma probe than patients with a negative LSG (100% vs. 38%, p < 0.001). In patients with a negative LSG, supplementary blue dye mapping increased the SN localization rate from 38 to 90%. The SN identification rate was 97% in the whole series.

Isotope-guided surgery was reliable, with a 99% localization rate for nonpalpable breast lesions and an 82% SN localization rate. The success rate of SN identification could be improved to 97% with the addition of blue dye mapping for patients with negative drainage on lymphoscintigraphy.