METHODS: Between 2000 and 2004, 1082 patients from several surgical teams, underwent breast lymphoscintigraphy following the protocol of a Nuclear Medicine unit. Of these, 858 patients (Group I), who had all the necessary data for the present study, were assessed. A number of 817 patients were submitted to intradermal injections: 395 (46.03%) perilesionally and 432 (50.35%) surrounding the scar. A total of 41 (4.77%) patients underwent subareolar injections. Out of the 858 patients, 422 had the lesion in the right breast and 433 in the left one, and only three patients presented bilateral lesions. The injected dose was 0.8-1.2 mCi, calculated for the day of surgery, in a total volume of 0.8 ml, distributed among four points around the lesion, breast scar or subareolar. Another specific group with 231 patients (Group II), from a single surgery team, was comparatively analyzed. Of these, 222 (96.1%) underwent SLNB with blue dye associated. The volume of blue dye was 2-4 ml and it was injected preferably according to ^99mTc-Phytate injection sites.

RESULTS: In Group I, a mean of 1.49 sentinel lymph node (SLN) per patient was found, and migration of the radiocolloid didn't occur in 17 (1.86%) patients. We also observed the presence of SLN in internal mammary chain in 16 (1.86%) patients, supraclavicular region in 9 (1.04%) patients and intramammary in 9 (1.04%) patients. In Group II, out of the 231 patients, 178 (77%) had had a previous biopsy. A mean of 1.7 SLN per patient was found in this group and 44 (19%) had conventional axillary dissection at the same cirurgical intervention. There was no radiocolloid migration and identification of blue dye in 8 (3.46%) and 35 (15.76%) patients, respectively, and SLN in the internal mammary chain was evidenced in 5 (2.16%) patients. A review of the current literature, which uses the same methodological bases but different radiotracers, shows comparable results to those obtained in this study with ^99mTc-Phytate.

CONCLUSION: A visualization of approximately 2% of internal mammary chain, regardless of the group analyzed, was compatible with the literature results described with non-deep injections. Migration indices of ^99mTc-Phytate are very high. Regardless of the group evaluated, the results obtained in the current study are at least similar to or even better than those in which other radiotracers are used. Therefore, ^99mTc-Phytate has been definitely incorporated into the practice of radioguided surgeries for SLNB as another radiotracer of excellence.