The effect of radiocolloid preference on major parameters in sentinel lymph node biopsy practice in breast cancer

The possible effects of radiocolloid preference on sentinel lymph node biopsy (SLNB) were investigated.

A total of 200 patients with T1-2N0M0 breast cancer were evaluated. The first 100 patients underwent SLNB using (99m)Tc tin colloid (TC) and the next 100 using (99m)Tc nanocolloid (NC). Radiocolloid was injected intradermally at four quadrants of the periareolar region the day before surgery. All patients underwent lymphoscintigraphy 1 h after injection. All nodes having fourfold activity of the background were harvested using gamma probe.

Sentinel lymph node (SLN) identification rate by gamma probe was 98% in each group. The number of SLNs identified by lymphoscintigraphy, gamma probe and pathological evaluation was 1.39 ± 0.7, 1.70 ± 1.0 and 2.23 ± 1.70 in the TC and 2.03 ± 0.94, 2.60 ± 1.36 and 3.05 ± 1.90 in the NC group, respectively (P<.05). Metastatic SLN was found in 24 (24.4%) of 98 patients in the TC group and 41 (41.8%) of 98 patients in the NC group (P=.04). None of the patients showed dispersion to internal mammarian lymph nodes. Lymphatic vessel visualization was observed in eight (8.1%) of 98 TC patients and in 47 (47.9%) of 98 NC patients (P=.000). SLNs were the only metastatic node(s) in 54.1% of TC and 73.1% of NC patients.

The periareolar intradermal injection technique gives a high detection rate in the localization of SLNs independently from the choice of the tracer. Mean SLN numbers and lymphatic vessel visualization frequency were significantly higher using a smaller albumin Tc-99m nanocolloid as compared to a stannous fluoride Tc-99m tin colloid. The results of our study support the idea that the influence of increased number of SLNs on positive SLN frequency is critical.