Lymphoscintigraphy and gamma probe tracing in detecting breast cancer lymph node involvement: Can they replace axillary lymph node dissection?

Background: Axillary lymph node status is the most important pathological d eterminant of prognosis in early breast cancer. However, axillary lymph nod e dissection (ALND) performed for pathological assessment is not without co sts and morbidity. Recently, radioisotope-guided sentinel node biopsy (SNB) has been proposed as a promising technique for staging breast cancer patie nts. Aim of the study: In this study we report our experience (76 patients) in r adioguided sentinel node (SN) biopsy in breast cancer, The study was divide d into two phases: the first represents our learning curve, necessary to es tablish our guidelines for its use In clinical practice, while the second p hase was aimed at assessing the feasibility of SN localization using preope rative lymphoscintigraphy and intraoperative gamma probe (GP) detection. Methods: All patients underwent lymphoscintigraphy (LS) up to two hours aft er tracer delivery (Tc-99m-micro-nanocolloid, four i.d. injections of 200 m u Ci/200 mu L around the primary lesion) 24 hours before surgery and GP tra cing during surgery, Subsequently ALND was performed for pathological asses sment. Results: SNs were identified in 73/76 patients using LS and in 72/76 using GP. In one case the SN was detected by GP alone while in two cases GP was n ot able to locate the SN although it had been identified by means of LS, Th irty-three of these 73 patients had axillary node involvement, In 31/33 cas es the SN was the only positive node, No positive nodes were found in the r emaining 40 ALNDs where SNs were identified. Thus, according to our experie nce 40/73 ALNDs could have been avoided. SNB seems to be a very interesting technique but further experience in lymph node radioisotope tracing is nee ded.