Identification of the sentinel lymph node using hemosiderin in locally advanced breast cancer / Identificação do linfonodo sentinela utilizando hemossiderina em casos de câncer de mama localmente avançado

ABSTRACT Objective: to verify the agreement rate in the identification of sentinel lymph node using an autologous marker rich in hemosiderin and 99 Technetium (Tc99) in patients with locally advanced breast cancer. Methods: clinical trial phase 1, prospective, non-randomized, of 18 patients with breast cancer and clinically negative axilla stages T2=4cm, T3 and T4. Patients were submitted to sub-areolar injection of hemosiderin 48 hours prior to sentinel biopsy surgery, and the identification rate was compared at intraoperative period to the gold standard marker Tc99. Agreement between methods was determined by Kappa index. Results: identification rate of sentinel lymph node was 88.9%, with a medium of two sentinel lymph nodes per patients. The study identified sentinel lymph nodes stained by hemosiderin in 83.3% patients (n=15), and, compared to Tc99 identification, the agreement rate was 94.4%. Conclusion: autologous marker rich in hemosiderin was effective to identify sentinel lymph nodes in locally advanced breast cancer patients.

RESUMO Objetivo: verificar a taxa de concordância na identificação do linfonodo sentinela utilizando um marcador autólogo rico em hemossiderina e o Tecnécio 99 (Tc99) em casos de câncer de mama localmente avançados. Métodos: ensaio clínico fase 1, do tipo prospectivo, não randomizado, em 18 pacientes portadoras de câncer de mama com axila clinicamente negativa em estádio T2=4cm, T3 e T4. As pacientes foram submetidas à injeção subareolar de um marcador autólogo rico em hemossiderina 48 horas antes do procedimento cirúrgico para biópsia do linfonodo sentinela, e sua taxa de identificação foi comparada, no intraoperatório, com o marcador radioativo Tc99 (padrão-ouro). A concordância entre os métodos foi estabelecida pelo índice de Kappa. Resultados: a taxa de identificação do linfonodo sentinela foi de 88,9%, com uma média de dois linfonodos sentinelas por paciente. O estudo identificou os linfonodos sentinelas corados com hemossiderina em 83,3% dos casos (n=15), quando comparados com a taxa de identificação do Tc99, tendo sido observada concordância em 94,4% dos casos estudados. Conclusão: o marcador autólogo rico em hemossiderina se mostrou eficaz na identificação do linfonodo sentinela em casos de câncer de mama localmente avançado.

Comparison between hemosiderin and Technetium-99 in sentinel lymph node biopsy in human breast cancer

PURPOSE: To assess the safety and potential equivalence of the use of hemosiderin compared to the Technetium-99 in sentinel lymph node biopsy in human breast cancer. METHODS: Non-random sample of 14 volunteer women diagnosed with breast cancer with primary tumors (T1/T2) and clinically tumor-free axilla were submitted to the identification of sentinel lymph node using hemosiderin obtained from autologous blood injected in the periareolar region 24h before surgery on an outpatient basis. Patients received preoperative subareolar intradermal injection of Technetium-99 in the immediate preoperative period. Patients were submitted to sentinel lymph node biopsy, with incision in the axillary fold guided by Gamma-Probe, dissection by planes until the identification of the point of maximum uptake of Technetium-99, identifying the marked nodes and their colors. All surgical specimens were sent for pathological and immunohistochemical study. RESULTS: The results showed no evidence of side effects and/or allergic and non-allergic reactions in patients submitted to SLNB with hemosiderin. The SLN identification rate per patient was 100%. SLNB identification rate per patient with hemosiderin was the same as that of Technetium, with a concordance rate of 100% between the methods. CONCLUSION: Hemosiderin is a safe dye that is equivalent to Technetium in breast sentinel lymph node biopsy.