Lymph Nodes & Vessels

• what types of examinations of the lymphatic system are there?

  • Dynamic Lymphoscintigraphy (DLS)
  • Quantitative DLS
  • Sentinel lymph nodes scintigraphy
• what is dynamic lymphoscintigraphy?

  diagnostic method used in NM that enables visualization of lymph nodes
• what Rf is used in dynamic lymphoscintigraphy?

  99mTc nanocol; dose = 100-120 MBq

  Intradermally using 2 insulin syringes (2 doses)
• how is a patient prepped for dynamic lymphoscintigraphy?

  1. Stop the use of venatic drugs before the test
  2. At the department, the patient puts on bandages, stockings and pieces of clothing that restrict the movement of lymph through the limbs
  3. Limbs must not be cold or hot
  4. Barefoot during examination
• what is the procedure for dynamic lymphoscintigraphy?

  1. Intradermal injection of RF between finger 1-2, and finger 4-5 on leg or arm
  2. Use of leap collimator
  3. Dynamic recording is performed immediately
  4. Position detectors from above with centering on the pelvic area (15images/120sec)
  5. Two static images are taken immediately after the end of the dynamic study and injection site (2images/60sec)
  6. Whole body limb scan is performed
  7. Exercise (80-90min after injection)
  8. Another whole body limb scan is performed
  9. Two static images are taken
  10. SPECT/CT if needed
• indications for dynamic lymphoscintigraphy?

  • Evaluation of lymphatic drainage integrity
  • Quantification of lymph flow
  • Identification of patients at high risk of developing lymphedema after dissection of axillary lymph nodes
  • Evaluation of the effect of lymphedema therapy
  • Assessment of lymph leakage in atypical cases
• Difference between dynamic quantitative scintigraphy and dynamic qualitative scintigraphy?

  Quantitative: It is used to estimate the transport time and assess the course of lymphatic vessels

  Qualitative: We evaluate the intensity of the displayed lymph node
• what is a sentinel lymph node?

  first lymph node or set of lymph nodes with direct lymphatic drainage from the primary tumor.
• what is the role of a sentinel lymph node?

  know the organs which will be primarily reached by the metastasizing cancer cells from the primary tumor.
• what Rf is used in sentinel lymph node scintigraphy?

  99m-Tc colloid
• Sentinel lymph node scintigraphy procedure?

  1. Injection of Rf in location of tumor
  2. Patient positioning at gamma camera
  3. Dynamic lymphoscintigraphy displays the site of injection around the tumor and the flow of lymph to target the SLNs
  4. YELLOW ARROW indicates the 6 injections around the tumor, RED ARROW indicates the sentinel lymph node
  5. After 2 hours sentinel lymph nodes denote the position on the skin
  6. Before surgery: application of ‘Patten-blau’ (marking solution)
  7. Measurement of removed SLN (after 20 hours)
• indications for sentinel lymph node scintigraphy?

  detecting sentinel lymph node in malignant melanoma and cancers
• advantages of preoperative sentinel lymph node mapping and SPECT/CT?

  • Exact anatomical location of SNs
  • Greater number of SNs than on planar images
  • Deep SNs or close to the injection site
  • Lymphatic drainage to unusual locations
  • Visualization of bilateral SNs
• Hybrid tracers contain both radioactive and fluorescent label (eg. indocyanine green (ICG) + 99mTc-nanocolloid)