Sentinel Lymph Node Mapping in Breast Cancer: Initial Experience of a Multidisciplinary Team

Abstract

Introduction: Breast cancer is one of the leading causes of cancer-related deaths in women; it is the most frequently diagnosed cancer in women in the United States with a lifetime risk of dying of about 3.4%. Regional lymph node involvement is quite early in breast carcinoma and axillary lymph node metastasis is an important predictor of recurrence and survival, particularly in invasive ductal histology of breast carcinoma. Localization of sentinel lymph node/nodes followed by frozen section and histopathological evaluation helps to prevent unnecessary axillary nodal dissection and, hence, reduces associated post-surgical morbidity. Sentinel nodes are the first ones to receive lymph-borne metastatic cells and, hence, lymphoscintigraphy followed by biopsy is quite reliable to detect nodal metastasis, particularly at an early stage (I, II) of breast cancer. Methods: Here we will share our experience of introducing procedure, personnel training, and workflow of sentinel lymph node lymphoscintigraphy in breast cancer patients at our cancer institute to help other centers establish programs for this study. Results: Initially, 10 procedures were performed, all of which were successful in the localization of sentinel nodes and played a substantial part in the surgical planning of breast cancer. Planar lymphoscintigraphy and single-photon emission computerized tomography (SPECT)-CT images of our first patient revealed radiotracer avidity in the lymph node in the ipsilateral axilla, which was later on diagnosed as metastatic resulting in axillary nodal clearance. Conclusions: In multidisciplinary/closely-placed surgical, pathological, and hybrid imaging facility settings, lymphoscintigraphy provides a quick, accurate, and better way of nodal localization leading to correct surgical decision-making. In addition to planar imaging, SPECT-CT acquisition significantly improves the specificity of the lymphoscintigraphy procedure, which is beneficial for patients to avoid false-positive results, thus saving breast cancer patients from potential adverse effects of surgery.

Comparative aspects of targeted sentinel lymph node mapping in veterinary and human medicine: opportunities for future research

“…The sentinel lymph node (SLN) is a tumor’s primary or first draining lymph node(s). Understanding the SLN allows for decreased surgical dissection, more accurate lymph node extirpation, and better overall outcomes ( 10 , 11 ). Comparative cancers in dogs, cats, and humans tend to have similar lymphatic metastasis rates, making them a good model for comparison.…”

“…For example, dogs and cats have 8–10 mammary glands evenly distributed on their ventral abdomen, while humans have 2 mammary glands closer to the forearms. In over 90% of clinically node-negative human breast cancer patients, SLN mapping and biopsies are regarded as crucial diagnostic tests due to the large number of axillary lymph nodes ( 10 , 11 ). In dogs with mammary cancer, the SLN was determined to be the axillary or accessory axillary lymph node(s) when the tumor was in the first, second, or third mammary gland and the superficial inguinal and medial iliac lymph node(s) when the tumor was in the fourth mammary gland ( 14 ).…”

“…Interestingly, there seems to be wide variation and a lack of clear pattern for the tumors located at the fifth or inguinal mammary gland ( 14–17 ). Therefore, in companion animals, the SLN could be the axillary or superficial inguinal lymph node, depending on the location of the affected mammary gland, compared to a human patient with breast cancer where the SLN is typically the axillary lymph node ( 10 , 11 , 16 , 18 ).…”

“…Interestingly, there seems to be wide variation and a lack of clear pattern for the tumors located at the fifth or inguinal mammary gland (14)(15)(16)(17). Therefore, in companion animals, the SLN could be the axillary or superficial inguinal lymph node, depending on the location of the affected mammary gland, compared to a human patient with breast cancer where the SLN is typically the axillary lymph node (10,11,16,18). This review will focus on comparative aspects of SLN mapping as a reference for the potential inclusion of companion animals in future developmental pipelines for targeted SLN mapping agents.…”