Sentinel Lymph Node Biopsy (SLNB)
Norm of Sentinel Lymph Node Biopsy (SLNB)
A sentinel lymph node is defined as a lymph node that stains blue or is radioactive.
Usage of Sentinel Lymph Node Biopsy (SLNB)
Helps avoid total axillary node dissection during early breast cancer; provides staging information for operable invasive breast cancer; identifies location of sentinel node for subsequent tumor resection. Also used to help diagnose malignant melanoma, and head and neck cancer. SLNB is being studied for its usefulness in evaluating other types of solid tumors.
Description of Sentinel Lymph Node Biopsy (SLNB)
Metastasis to lymph nodes can be determined by identifying lymph flow from the tumor site to the primary lymph node via radio-guided biopsy. The sentinel lymph node is the first lymph node in the lymphatic basin to receive lymph flow from a primary tumor. Thus it will be the first node to contain metastasis and can be identified on lymphoscintigraphy by following the blue dye to the most proximal node.
Professional Considerations of Sentinel Lymph Node Biopsy (SLNB)
Consent form IS required for the biopsy portion of this procedure.
Risks
Bleeding; infection; reaction to the dye, more so when isosulfan blue is used than when methylene blue is used.
Contraindications
Sentinel lymph node biopsy for work-up of breast cancer is contraindicated in clients who have had previous breast surgery or radiation to the breast, as well as in clients who have clinically palpable nodes, locally advanced breast disease, tumors in more than one location in the breast, lymphatic problems, burns, breast reduction surgery, or breast implants.
Preparation
- 3–5 mL of isosulfan blue radioactive tracer is injected subdermally around the circumference of the tumor (for palpable masses) or peritumorally or intratumorally under the guidance of ultrasound. Alternatively, methylene blue dye has been used and has less incidence of allergic reaction.
- The site is then massaged for 5 minutes to promote migration of the tracer.
- Just before beginning the procedure, take a “time out” to verify the correct client, procedure, and site.
Procedure
- 2–6 hours after tracer injection, the area of the tumor site is scanned via lymphoscintigraphy to identify the “hot spot,” which is marked on the skin and later used for localization of tumor for excision. The remainder of the lymph node basin is examined for residual radioactivity.
Postprocedure Care
- A dry, sterile dressing is required.
- Assess vital signs and the site for bleeding.
Client and Family Teaching
- Consume only clear liquids after midnight and before the biopsy.
- A lumpectomy is usually performed immediately after the sentinel node biopsy.
- Do not lift more than 10 pounds for 48 hours after the procedure.
- Final results may take up to 1 week.
- Observe for signs of infection and report to the physician: increasing pain, redness, swelling, drainage, or temperature >101 degrees F (38.3 degrees C).
Factors That Affect Results
- Surgeon's skill and frequency of performing procedure.
- The shine-through effect of radiocolloid from the primary site may affect localization of the sentinel node.
Other Data
- In one study (Izawa et al, 2005), SLNB was found not to be useful for evaluation of penile cancer.
