Objective: To obtain correct location of non-palpable breast lesions, with high suspicion of malignancy and detection of SN by radiosotopic techniques.
Material and methods: Thirty-one patients whose ages ranged from 35 to 79 years, with non-palpable breast lesions detected by mammography and/or ultrasonography were studied. All the patients were diagnosed of breast cancer and treated with primary chemotherapy. All the patients underwent total axillary dissection. At 24 hours of the intervention, all patients received one dose of 37 MBq (1 mCi) of 99mTc labeled macroaggregated albumin (MAA) in the center of the lesion by ultrasonographic guide. Scintigraphic images were performed in anterior and lateral projections (in prone decubitus with hanging breast) to verify the correct location of the radiopharmaceutical. After, a study of the SN was performed by subdermal administration of an 18 MBq (0.5 mCi) dose of 99mTc labeled nanocolloid. The SN site was labeled on the skin with indelible ink. The intrasurgical site of the breast lesion and SN was performed using a gamma detector probe. Correct placement of the intralesional radiopharmaceutical, existence of disease free borders and histological study of SN were performed by the pathologist in the surgical act. The differed pathology study was performed with hematoxilin-eosin and immunohistochemistry.
Result: In 29 of the 31 lesion sites, there was good placement of the radiotracer (93.5 %). There was 1 case of contamination of the needle pathway and another that did not coincide with the lesion, due to poor placement. Location of the SN was 96 % in the axilla and 4 % in axilla and internal mammary chain. The SN was located in surgery in 28/31 patients (90 %).
Conclusion: Simultaneous radioguided location of the hidden breast lesions and sentinel node is a simple method, which is well tolerated by the patients and can be done in a single operation act.