title: Localizing the sentinel node in cutaneous melanoma: gamma probe detection versus blue dye.
abstract: BACKGROUND
  Sentinel node (SN) biopsy can be used to select patients with melanoma for therapeutic lymphadenectomy. We investigated the value of two methods to locate the SN: patent blue dye (PBD) and gamma probe detection of 99mTc-nanocolloid.
  
  
  METHODS
  One hundred ten patients with cutaneous melanoma were studied. Lymphoscintigraphy with 99mTc-nanocolloid was performed to determine the position of the SN. Before operation, PBD was injected at the same site as the radiopharmaceutical. When a blue node was identified intraoperatively, its radioactivity level was measured with the probe. In the absence of blue coloration, the probe was used to trace the SN.
  
  
  RESULTS
  Scintigrams visualized a total of 219 SNs in 141 basins. Eight SNs were not explored. One SN was not found. The remaining 210 and 27 additional intraoperatively identified SNs were excised. From the total of 237 removed SNs, 200 (84%) were found using PBD only. All 37 nodes that were not found with the PBD were localized with the probe so that the probe combined with PBD identified 99.5% of all SNs. In 23 patients the SN contained tumor. In three patients the SN was false-negative for metastasis.
  
  
  CONCLUSIONS
  The gamma probe together with PBD can identify more SNs (99.5%) than lymphatic mapping with PBD alone (84%).
authors.affiliation: Department of Surgery, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Ziekenhuis, Amsterdam, The Netherlands.
authors.forename: B A
authors.initials: BA
authors.lastname: Kapteijn
authors.forename: O E
authors.initials: OE
authors.lastname: Nieweg
authors.forename: I
authors.initials: I
authors.lastname: Liem
authors.forename: W J
authors.initials: WJ
authors.lastname: Mooi
authors.forename: A J
authors.initials: AJ
authors.lastname: Balm
authors.forename: S H
authors.initials: SH
authors.lastname: Muller
authors.forename: J L
authors.initials: JL
authors.lastname: Peterse
authors.forename: R A
authors.initials: RA
authors.lastname: Valdés Olmos
authors.forename: C A
authors.initials: CA
authors.lastname: Hoefnagel
authors.forename: B B
authors.initials: BB
authors.lastname: Kroon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004396:Coloring Agents; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008297:Male; D008545:Melanoma / Q000473:pathology*; D008875:Middle Aged; D011877:Radionuclide Imaging; D012394:Rosaniline Dyes; D012878:Skin Neoplasms / Q000473:pathology*; D013668:Technetium Tc 99m Aggregated Albumin
chemical_list: D004396:Coloring Agents; D012394:Rosaniline Dyes; D013668:Technetium Tc 99m Aggregated Albumin; C083602:technetium Tc 99m nanocolloid; C008769:sulfan blue