Lymphoscintigraphy

Indications:
  • melanoma- Sentinel node localization
  • breast cancer- Sentinel node localization
  • identify points of blockage in the lymphatic system
  • plan biopsy/surgery/assist with intraoperative gamma probe

Contraindications:

  • patients with clinically positive axilla
  • patients with an allergy to the radiopharmaceutical
  • patients with compete blockage of lymphatic system
  • may exclude patients with extensive previous surgery in the region of the primary tumor site
  • pregnancy should be considered


Questions asked in Patient History:
  • Are you pregnant
  • Are you breast feeding
  • Where is the primary lesion
  • Do you have any known allergies
  • What medication do you take
  • Have you have previous lymph nodes removed, if so on what side
  • Do you have a history of cancer
  • Do you have any preexisting medical conditions

  • Radionuclide: Tc-99m
  • Radiopharmaceutical: Tc-99m Sulfur Colloid, either filtered, ultra filtered, or unfiltered
  • Adult dosing: 4-6 (possible low of 1 or as high as 8) injections of 0.1 mCi per 0.1 ml, around 0.4-1 mCi
  • Pediatric dosing: 0.4-1.0 mCi
  • Method of administration:-Melanoma: 2-6 subcutaneous or intradermal injections around cancer site, surgery, or region of interest.
    -Breast lesions: 4-6 intradermal injections surrounding peri-tumoral or peri-aereolar tissue at 3-, 6-, 9-, and 12-o’clock positions around tumor site. Injections may be done under ultrasound to locate tumor. You can massage the area of injection to stimulate the lymphatic system, and then cover the injection site.
    -May include lidocaine or sedation to reduce pain of injections. Flush the injection to ensure the dose is out of the syringe.
  • Method of Localization: compartmental, phagocytosis
  • Physical Half-life: 6 hours



Patient Preparation:

What does the patient need to do prior to coming for the procedure?

Patients should follow preoperative restrictions if the procedure is performed on the same day as scheduled surgery


Side Effects:

  • The sulfur colloid can cause a burning sensation during the injection but you may use sodium bicarbonate to alter the pH for the burning sensation if the institution allows
  • Lymphedema
  • Seroma
  • Infection
  • Chronic limb adema
  • Perathesia
  • loss of dexterity
  • nerve damage
Equipment Used:
Type of Camera or Probe
Gamma Camera
Collimator used:
LEHR
Acquisition Setup:

Photopeak(s): 140 KeV

Window(s): 20%


Dynamic: View(s)
Anterior, posterior, and lateral or oblique depending on injection location
Matrix: 128x128
Time/Frame: 10sec/frame
Number of Frames: 60 frames

Statics: View(s)

Anterior, posterior, and lateral or oblique depending on injection location
Matrix: 256x256x16
Total Counts or Duration: 5 minutes

Transmission scan
Co-57 sheet source behind patient,camera over top of patient, acquire outline of patient's body for both anterior and lateral images
Scan Speed: 5 minutes per bed, # of beds depend on the patient's height, but generally about 15-20 minutes


SPECT:
180 or 90 degree configuration
Total Rotation: 180 or 360
Starting point: 0 degrees
Matrix:
Time/Azmuiths
Number of Azmuiths:

Processing:
To best see draining lymph nodes one could lower the upper threshold of the display or use other contrast enhancement methods to improve the low count areas of the image.


Procedure:
Describe the procedure from verifying the requisition to completing the scan. Include any patient instructions pre- or post- injection/scan, delays between injection and imaging, and any side effects.
-First take patient history, and ensure you have the tumor location correct to determine what type of imaging you will do and where you will inject
-Clean the area you are going to inject
-Inject peritumoral or periaerolar with the correct number of injections in a clockwise fashion
-Cover and massage injection site
-Acquire the flow, and static images
-Acquire the transmission scan
-If the SN is visualized, mark on the patient using a point source, and use a marker to mark on their skin

Normal Uptake and common varients:
Insert an image of a normal scan. Describe the normal uptake, and any normal variants visualized.
Normal uptake will be in the lymph node of the area around the tumor/area of injection, the path of lymphatic drainage is predictable to the axillary lymph nodes.
breast-nm8.jpg
This image shows the lymph nodes in the axilla visualizing as the sentinel node, which is normal uptake for the scan.

Abnormal Uptake and causes:
Insert an image of an abnormal scan. Describe the abnormal uptake, and the cause of the abnormal uptake.

F4.large.jpg

Swollen limb indicates impaired lymph drainage

http://www.ajronline.org/content/197/6/1443.abstract

Artifacts

Insert an image with an artifact, and explain what the artifact is.
DA2DB4DC2C159FF8.png
Increased uptake in the injection site and the linear star artifact.

http://flylib.com/books/en/3.98.1.164/1/




References:
"Lymphoscintigraphy." Web. <http://www.ctf.edu.tr/anabilimdallari/pdf/225/Lymphoscintigraphy.pdf>.
Shackett, Pete. Nuclear Medicine Technology: Procedures and Quick Reference. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins, 2008. Print.