Sentinel Node Biopsy is a surgical procedure designed to determine whether cancer has spread to the nearby lymph nodes in the armpit from the primary tumor site in the breast. Lymph nodes are small, bean-shaped structures that drain lymphatic fluid and play a vital role in the body's immune system. In breast cancer, the first lymph nodes that cancer cells are likely to spread to are known as the sentinel nodes.

Purpose of Sentinel Node Biopsy:

The primary purpose of sentinel node biopsy is to accurately stage breast cancer, which is essential for determining the most appropriate treatment plan for each patient. By assessing the status of the sentinel nodes, the extent of the disease spread beyond the primary tumor can be determined. This information is crucial for making informed decisions regarding further treatment options, such as adjuvant therapy (chemotherapy, radiation therapy) and targeted therapies.

Procedure of Sentinel Node Biopsy:

• Preoperative Preparation: Before the procedure, patients undergo thorough evaluation, which may include imaging studies (such as ultrasound or PETCT) to identify the location of the primary tumor and the sentinel nodes. Patients may also receive a tracer injection, typically a radioactive substance or a blue dye, near the tumor site.

• Intraoperative Localization: During surgery, the surgeon uses a handheld probe to detect the tracer that has migrated to the sentinel nodes. The blue dye stains the sentinel nodes and helps to visualise them during surgery. These techniques help in precisely locating the nodes that are most likely to contain cancer cells.

• Sentinel Node Removal: Once the sentinel nodes are identified, they are carefully removed and sent to the pathologist for analysis.

• Pathological Examination: In most cases, frozen section evaluation of the sentinel nodes is performed under a microscope to determine whether cancer cells are present. This technique has a fairly high accuracy and takes a few minutes only. The result helps to guide the further intraoperative plan.

• Additional Lymph Node Evaluation (if necessary): In some cases, if the sentinel nodes are found to contain cancer cells, additional lymph nodes in the axilla (armpit) may be removed for further examination.

Benefits of Sentinel Node Biopsy:

• Accurate Staging: Sentinel node biopsy provides accurate staging of breast cancer, allowing clinicians to tailor treatment plans according to the extent of disease spread.

• Reduced Morbidity: Unlike traditional axillary lymph node dissection, which involves the removal of multiple lymph nodes, sentinel node biopsy targets only a few key nodes, reducing the risk of complications such as lymphedema (swelling of the arm).

• Minimally Invasive: Sentinel node biopsy is a minimally invasive procedure that can be performed as part of breast-conserving surgery (lumpectomy/wide excision) or mastectomy, minimizing the impact on the patient's overall recovery and quality of life.

• Personalized Treatment: By accurately determining the status of the sentinel nodes, clinicians can personalize treatment strategies, ensuring that patients receive the most appropriate and effective therapies for their specific situation.

Sentinel node biopsy has revolutionized the approach to lymph node evaluation in breast cancer surgery, offering accurate staging while minimizing the morbidity associated with traditional lymph node dissection.