title: The impact of nodal tumour burden on lymphoscintigraphic imaging in patients with melanomas.
abstract: OBJECTIVE
  To retrospectively study the influence of nodal tumour burden on lymphoscintigraphic imaging in 509 consecutive patients with melanomas.
  
  
  METHODS
  Bidirectional lymphatic drainage, the clear depiction of an afferent lymphatic vessel, time to depiction of the first sentinel lymph node (SLN) and number of depicted and excised nodes were recorded. Nodal tumour load was classified as SLN-negative, SLN micrometastases or macrometastases.
  
  
  RESULTS
  In the overall population, using multivariate regression analysis, a short SLN depiction time was significantly associated with the depiction of a greater number of radioactive nodes, a short distance between the primary tumour site and the nodal basin, younger age and lower nodal tumour burden. The proportion of patients with clear depiction of an afferent lymphatic vessel depended on the nodal tumour load (46% in SLN-negative patients, 57% in SLN positive patients, and 69% in patients with macrometastases; P = 0.009). Macrometastasis was significantly associated with delayed depiction of the first radioactive node and a greater number of depicted hotspots. In patients with clinically nonsuspicious nodes, i.e. the classical target group for SLN biopsy, clear depiction of an afferent vessel was significantly associated with a higher number of SLNs during dynamic acquisition, SLN micrometastasis and a higher overall number of metastatic lymph nodes after SLN biopsy plus completion lymphadenectomy. The excision of more than two SLNs did not increase the metastasis detection rate. In patients with bidirectional or tridirectional lymphatic drainage, the SLN positivity rates for the first, second and third basin were 25.4%, 11.7% and 0.0 %, respectively (P = 0.002).
  
  
  CONCLUSIONS
  In patients with clinically nonsuspicious lymph nodes, clear depiction of an afferent lymph vessel may be a sign of micrometastasis. Macrometastasis is associated with prominent afferent vessels, delayed depiction of the first radioactive node and a higher number of depicted hotspots.
authors.affiliation: Department of Dermatology, Venereology and Allergology, Georg August University of Göttingen, Robert-Koch-Str 40, 37075, Göttingen, Germany, lkre@med.uni-goettingen.de.
authors.forename: Lutz
authors.initials: L
authors.lastname: Kretschmer
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Bertsch
authors.forename: Pawel
authors.initials: P
authors.lastname: Bardzik
authors.forename: Johannes
authors.initials: J
authors.lastname: Meller
authors.forename: Simin
authors.initials: S
authors.lastname: Hellriegel
authors.forename: Kai-Martin
authors.initials: KM
authors.lastname: Thoms
authors.forename: Michael Peter
authors.initials: MP
authors.lastname: Schön
authors.forename: Carsten Oliver
authors.initials: CO
authors.lastname: Sahlmann
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging / Q000473:pathology; D061305:Lymphoscintigraphy; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000473:pathology; D008875:Middle Aged; D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin; D047368:Tumor Burden
chemical_list: D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin; C083602:technetium Tc 99m nanocolloid