The influence of radioisotope vehicle on breast sentinel node detection

Aim To assess the relationship between carrier molecule size and time elapsing between marker injection and sentinel node(s) biopsy in patients with breast cancer. Material The study performed on 122 women, in whom the sentinel node(s) was identified according to the procedure described below. In Group I (n = 72 patients), SN identification was done with radioisotope marker of 400–3000 nm molecule size (tin colloid). In Group II (n = 50 patients) radioisotope marker of <100 nm molecule size (colloidal albumin) was used. Methods All the patients of both groups received the markers with a single-point, intradermal, periareolar injection. Four hours after the injection (Group I – surgery in the next day) or immediately before the surgery (in this same day) (Group II), stationary lymphoscintigraphy was performed. Results Mean numbers of sentinel nodes identified with the radioisotope method in Groups I and II were 1.22 and 1.48, respectively. The difference was statistically significant (p < 0.01). Conclusions There is a relationship between the radioisotope marker molecule size and the injection-to-intra-operative evaluation time. Administration of small molecule size radioisotope marker several hours prior to the planned surgery appears to be the optimum procedure in this method of SN identification in patients with breast cancer.