Method for Uniform Performance of 

Sentinel Lymph Node (SLN) Biopsy/Dissection 

at Lexington Medical Center

Approved 1 April 2003

After several years of the various surgeons trying various protocols, Dr. Hood from Radiology had a multidisciplinary meeting which resulted in the below consensus protocol, approved by our hospital's Cancer Committee on the above date. This pertains to breast cases; melanoma cases are handled similarly (except that, melanomas can be midline & great care is taken to look for sentinel nodes on both right and left when the skin tumor is midline). [what OUR pathology exam is like]

[back to breast index]

I.    Patient Selection:

The technique is generally not indicated in the following situations:

a.    Primary tumor > 5 cm diameter

b.    Multifocal tumor

c.    Patient with breast implants or prior disfigurement

d.    Very obese patients

e.    Suspicious palpable axillary lymph nodes

*Please note, these are not absolute contraindications, and the final decision is left to the referring surgeon.  

II.    Patient Preparation:

None.  However, it is agreed that the patient will be scheduled in such a manner that the nuclear medicine department personnel have a full 90 minutes for the examination from the time of the injections to the end of imaging.  

III.    Method of Injection:

1. Patient information sheet completed which indicates the site of injection, the volume and dose injected, the time of injection, the radiologist who injected, and the quadrant of the primary tumor (UOQ, UIQ, LOQ, or LIQ).  A copy of this info sheet must accompany patient to OR.

2. Patient placed in supine position with arm at 90 degrees abduction (to replicate position in OR).

3. Minimum of personnel in area; maximize privacy for patient.

4. Subareolar method of radiopharmaceutical injection: The injection site is always the same regardless of tumor location.  No local anesthetic is used.  The areola is cleaned well with alcohol pads.

5. Four syringes are used, each with 0.2 mCi of filtered 99m-Tc SC for a total administered dose not to exceed 0.8 mCi; each syringe should contain no more than 0.4ml of NS such that total injected volume does not exceed 1.6 ml.  Each infection is made obliquely toward the nipple at a shallow angle to the skin to deliver the liquid bolus into the subareolar tissue at the 12, 3, 6, and 9 o'clock positions.  The injections should be shallow but not raise a visible wheal on the areola.  The puncture sites should be chosen immediately peripheral to the areola with the needle pointed centrally toward the nipple; the areola itself should not be punctured.  The entire amount should be slowly injected over a 15 second period to minimize patient discomfort.  The syringes should not be "tested" to clear the hub of any air prior to injection!  It is better to inject a little air into the skin than to spray radioactive liquid into the local environment.

6. Immediately after the injection a small Tegaderm patch or similar bandage is placed over the areola.  Shielding of the injection site should not be necessary with this approach.

7. After the bandage is placed and the syringe and needles properly discarded the patient is instructed to gently massage or knead her breast, or this may be performed by the technologist if necessary.  The gentle kneading of the breast should continue for at least 2-3 minutes, preferably for 5 minutes, and should not include direct manipulation of the nipple or the periareolar tissues close to the injection site.  

IV.    Imaging:

1. LFOV camera placed as close as possible to covered breast

2. LEAP collimator

3. 256 x 256 matrix

4. 1.2 zoom

   Images acquired immediately and every 30 minutes until sentinel node in axillary area is noted or 90 minute period allotted for test is exhausted.  The images consist of both emission and transmission scans. 

5. The emission scans are acquired in AP and LAT projections for 5 minute counts; the transmission scans are obtained concurrently (with the flood source placed) for 2 min counts.  Thus, four images are obtained for each 30-minute period.

   Note: The AP images are obtained with the arm remaining in 90 degrees of abduction; the LAT images are obtained with the arm fully extended above head.

6. Each set of four images for each time is filmed separately using a 4 on 1 format.  These should be labeled with the appropriate times.

7. Once sentinel node is identified, the AP and LAT images are studied to determine where to mark the skin site closest to the sentinel node.  A small mark should be made with a Sharpie.  If more than one node shows up at the same time, both should be marked.  It is important that the patient's arm be positioned at 90 degrees of abduction before marking the skin site.  If the sentinel node is not identified on the images at the 90 minute mark, then this is noted on the information sheet accompanying the patient to the operating room.

8. Regardless of outcome according to (g), the properly labeled films and the completed patient info sheet should accompany the patient to the OR.

Lymp node status: pathologist to be careful...may need IHC, too...to discern benign epithelial rests or nodal nevi from true metastases.

(posted 2 April 2003; addition 5 March 2007)