title: Imaging of lymphatic vessels in breast cancer-related lymphedema: intradermal versus subcutaneous injection of 99mTc-immunoglobulin.
abstract: OBJECTIVE
  The disordered physiology that results from axillary lymph node clearance surgery for breast cancer and that leads to breast cancer-related lymphedema is poorly understood. Rerouting of lymph around the axilla or through new pathways in the axilla may protect women from breast cancer-related lymphedema. The aim of the study was to compare intradermal with subcutaneous injection of technetium-99m ((99m)Tc)-labeled human polyclonal IgG (HIG) with respect to lymphatic vessel imaging.
  
  
  METHODS
  Six women with breast cancer-related lymphedema underwent unilateral upper limb lymphoscintigraphy, using a web space injection of (99m)Tc-labeled HIG, after intradermal and subcutaneous injections on separate occasions. Multiple sequential images were obtained of the affected upper limb and torso over 3 hr on each occasion. Accumulation of activity in blood was quantified from venous blood samples taken from the opposite arm.
  
  
  RESULTS
  Imaging after intradermal injection clearly showed discrete lymphatic vessels in five of six patients, in contrast to imaging after subcutaneous injection, which did not show any discrete vessels in any patient. Intradermal injection resulted in more rapid visualization of cutaneous lymph rerouting than subcutaneous injection in six of six patients. Recovery of injected (99m)Tc-labeled HIG in venous blood was greater after intradermal injection in six of six patients.
  
  
  CONCLUSIONS
  In patients with breast cancer-related lymphedema, lymphatic vessels are more clearly depicted after intradermal than subcutaneous injection as a result of direct access of radiotracer to dermal lymphatics. This finding has implications for imaging lymphatic vessel regeneration and lymph rerouting.
authors.affiliation: Cambridge Breast Unit, Addenbrooke's Hospital, Cambridge, UK.
authors.forename: Susan
authors.initials: S
authors.lastname: O'Mahony
authors.forename: Chandra K
authors.initials: CK
authors.lastname: Solanki
authors.forename: Robert W
authors.initials: RW
authors.lastname: Barber
authors.forename: Peter S
authors.initials: PS
authors.lastname: Mortimer
authors.forename: Arnie D
authors.initials: AD
authors.lastname: Purushotham
authors.forename: A Michael
authors.initials: AM
authors.lastname: Peters
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000150:complications*; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000008:administration & dosage; D007279:Injections, Subcutaneous; D042601:Lymphatic Vessels / Q000000981:diagnostic imaging*; D008209:Lymphedema / Q000000981:diagnostic imaging* / Q000209:etiology*; D008875:Middle Aged; D011877:Radionuclide Imaging; D013667:Technetium / Q000008:administration & dosage
chemical_list: D007136:Immunoglobulins; C065376:technetium Tc 99m immunoglobulin; D013667:Technetium