Abstract P1-02-03: Our preliminary experience: Ultrasound guided localization of axillary lymph nodes using activated charcoal before neoadjuvant chemotherapy for guidance in axillary surgery in breast cancer patients
Authors: Pineiro Africa , Cosaka Maria L , Amat Mora , Colo Federico , Negri Maria L , Salinas Juliana Marulanda , Alejandra Varela , Martin Loza , Carolina Ponce , Constanzo Victoria , Nervo Adrian , Mysler Daniel C 
Published: March 2020

Abstract
The study objective is to review the rate of identification of the biopsied lymph node during surgery by placing activated charcoal in patients with node-positive breast cancer prior to neoadjuvant chemotherapy (NAC). The secondary objective is to validate the concordance of tattooed lymph node with the sentinel nodes resected during surgery at the final pathological examination. Background: The SENTINA study concluded that for cN1 breast cancer patients that had neoadjuvant chemotherapy and afterwards had two or more sentinel node localization examined, the false negative rate (FNR) was above 10%. The ACOSOG Z1071 study showed that clipping the positive lymph node and its preoperative localization reduces the false negative rate (FNR) significantly. The use of charcoal suspension for tattooing positive nodes during the biopsy is an effective and minimal invasive technique. It avoids placing a clip and posteriorly marking it with wire or radioactive seed previous to surgery, reducing the number of procedures, costs and time. When correctly placed charcoal suspension does not affect the pathological examination. Methods: This is a retrospective pilot study form January 2016 to March 2019 that enrolled 13 cancer patients aged (26 -50 years) with clinical T1-4, N 1-2, M0 in which NAC was performed. Ultrasound axillary lymph node core biopsy and tattooing with 0,3 ml of activated charcoal suspension (Mamograf ™) in positive lymph nodes was performed prior to NAC. Patients after NAC had axillary surgery. The sentinel nodes (SN) were identified as the nodes that contained blue dye and technetium-99m. During surgery both the SN, and also the tattooed lymph nodes were removed. Evaluation of the final pathological analysis concordance between the sentinel nodes and the tattooed lymph node was performed. Results: The analysis showed that surgeons were able to successfully identify the biopsied lymph node marked with activated charcoal in 11 (84,6%) cases. The final pathology results showed concordance between the sentinel nodes and the tattooed lymph in 11 cases. There were no cases in which the tattooed lymph node did not correspond to the sentinel node. In 2 (15,4%) cases charcoal wasn´t identified neither during the surgery nor during the pathological examination. No charcoal migration to other lymph nodes was identified during surgery and in all of the cases pathological examination was not affected when the final pathology was analyzed. The final pathology results in tattooed lymph nodes was of metastases in 4 cases (36,4%), post NAC nodal fibrosis in 2 cases (18,2%) and reactive adenitis in 5 cases (45,4%). Conclusion: When visualized on ultrasound, placing activated charcoal in patients with node-positive breast cancer prior to NAC, had shown to be successful and have a high identification rate during axillary surgery. This subset analysis provides preliminary information that using charcoal suspension for tattooing positive lymph nodes before NAC has a high identification rate during axillary surgery. Larger prospective studies may probe that this new technique may change clinical approach when it comes to identifying positive lymph nodes in breast cancer patients after NAC by successfully targeting and removing them with the need of fewer radiological exams and reducing surgical times as well as overall costs.
Citation Format: Africa Pineiro, Maria L Cosaka, Mora Amat, Federico Colo, Maria L Negri, Juliana Marulanda Salinas, Varela Alejandra, Loza Martin, Ponce Carolina, Victoria Constanzo, Adrian Nervo, Daniel C Mysler. Our preliminary experience: Ultrasound guided localization of axillary lymph nodes using activated charcoal before neoadjuvant chemotherapy for guidance in axillary surgery in breast cancer patients [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-02-03.