Background: The purpose of this study was to determine the feasibility of both lymphatic mapping and probe-guided primary tumor excision by use of intralesional tracer administration in clinically occult breast cancer.
Methods: Sixty patients with a clinically occult breast lesion were prospectively included. Lymphoscintigraphy was performed after intratumoral injection of 99mTc-labeled nanocolloid guided by ultrasound or stereotaxis. A catheter over a localization wire was inserted for intraoperative blue dye administration by using the same imaging techniques. After sentinel node identification, the gamma-ray detection probe was used for radio-guided wide local excision in patients who underwent breast-conserving therapy.
Results: A sentinel node was visualized on the scintigrams in 56 patients (93%) and could be identified intraoperatively in 58 patients (97%). A sentinel node contained tumor in 10 (17%) of these patients. Extra-axillary sentinel nodes were visualized in 43%, were collected in 38%, and contained metastasis in 7% of the patients. Complete excision of the primary tumor could be accomplished in 39 (87%) of 45 patients.
Conclusions: Both sentinel node biopsy and probe-guided excision of a nonpalpable breast cancer is feasible with the aid of intralesional tracer administration. Sentinel node metastasis was found in 17% of the patients. A remarkably high percentage of extra-axillary drainage (43%) was observed.