title: Sentinel node biopsy by indocyanine green retention fluorescence detection for inguinal lymph node staging of anal cancer: preliminary experience.
abstract: BACKGROUND
  There is some evidence that sentinel lymph node (SLN) biopsy guided by dye injection and/or radioisotopes can improve staging of inguinal lymph nodes (LNs) in anal cancer. This study was performed to investigate the feasibility of fluorescence detection of SLN and lymphatic mapping in anal cancer.
  
  
  METHODS
  Twelve patients with anal cancer without evidence for inguinal LN involvement were included in the study. Intraoperatively, all patients received a peritumorous injection of 25 mg indocyanine green (ICG) for fluorescence imaging of the SLN with a near-infrared camera. For comparison, conventional SLN detection by technetium-(99)m-sulfur radiocolloid injection in combination with blue dye was also performed in all patients. The results of both techniques and the effect on the therapeutic regimen were analyzed.
  
  
  RESULTS
  Overall, ICG fluorescence imaging identified at least one SLN in 10 of 12 patients (detection rate, 83%). With the combination of radionuclide and blue dye, SLN were detected in 9 of 12 patients (detection rate, 75%). Metastatic involvement of the SLN was found in 2 of 10 patients versus 2 of 9 patients. Patients with metastatic involvement of the SLN received extended radiation field with inguinal boost.
  
  
  CONCLUSIONS
  ICG fluorescence imaging allows intraoperative lymphatic mapping and transcutaneous SLN detection for selective biopsy of inguinal SLN in anal cancer. This technique should be further evaluated in comparative studies with larger patient numbers.
authors.affiliation: Department of General Surgery and Surgical Oncology, Robert Rössle Hospital, Helios Hospital Berlin-Buch, Berlin, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Hirche
authors.forename: S
authors.initials: S
authors.lastname: Dresel
authors.forename: R
authors.initials: R
authors.lastname: Krempien
authors.forename: M
authors.initials: M
authors.lastname: Hünerbein
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001005:Anus Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D004396:Coloring Agents; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007208:Indocyanine Green; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D021701:Sentinel Lymph Node Biopsy; D013671:Technetium Tc 99m Sulfur Colloid; D055815:Young Adult
chemical_list: D004396:Coloring Agents; D019275:Radiopharmaceuticals; D013671:Technetium Tc 99m Sulfur Colloid; D007208:Indocyanine Green