title: Added value of the hybrid tracer indocyanine green-99mTc-nanocolloid for sentinel node biopsy in a series of patients with different lymphatic drainage patterns.
abstract: BACKGROUND
  Indocyanine green (ICG)-(99m)Tc-nanocolloid is a novel hybrid fluorescent radioactive tracer for sentinel node (SN) biopsy. This study has aimed to evaluate the added value of this novel versatile tracer in a series of patients with different malignancies.
  
  
  METHODS
  Twenty patients (with penile carcinoma, oral cavity tumors, melanoma) were consecutively included between March-May 2012. Planar lymphoscintigraphy was performed 15 min and 2h after injection of ICG-(99m)Tc-nanocolloid followed by SPECT/CT. Blue dye (1 ml) was injected in 14 patients in surgery room. Intraoperatively, SNs were localized using a gamma probe and visualized by optical SN-detection using blue dye and fluorescence imaging. Finally, a portable gamma camera was used to confirm complete SN removal.
  
  
  RESULTS
  At least one SN was identified by SPECT/CT in all patients. All SNs (total 68, 100%) were excised using a combination of radio- and fluorescence guidance: 89.7% were intraoperatively localized with the gamma probe. The remaining SNs, located near the injection site, were localized using fluorescence imaging. During the surgery, 97% of the SNs were fluorescent while only 39.2% were stained blue. Ex vivo, all SNs were both radioactive and fluorescent. The SN was positive in 5 patients.
  
  
  CONCLUSIONS
  Synchronous radio- and fluorescence guided SN biopsy is feasible using ICG-(99m)Tc-nanocolloid. This hybrid approach combines the beneficial properties of both modalities. Adding fluorescence imaging improves optical SN detection compared to blue dye. It has been shown to be especially useful in the localization of SNs near the injection site.
authors.affiliation: Servicio de Medicina Nuclear, Hospital Dr. Peset, Valencia, España. lorefrontado@gmail.com
authors.forename: L M
authors.initials: LM
authors.lastname: Frontado
authors.forename: O R
authors.initials: OR
authors.lastname: Brouwer
authors.forename: N S
authors.initials: NS
authors.lastname: van den Berg
authors.forename: H M
authors.initials: HM
authors.lastname: Mathéron
authors.forename: S
authors.initials: S
authors.lastname: Vidal-Sicart
authors.forename: F W B
authors.initials: FW
authors.lastname: van Leeuwen
authors.forename: R A
authors.initials: RA
authors.lastname: Valdés Olmos
mesh_terms: D000328:Adult; D000368:Aged; D004396:Coloring Agents; D005260:Female; D006801:Humans; D007208:Indocyanine Green; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000473:pathology; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D013668:Technetium Tc 99m Aggregated Albumin
chemical_list: D004396:Coloring Agents; D013668:Technetium Tc 99m Aggregated Albumin; C083602:technetium Tc 99m nanocolloid; D007208:Indocyanine Green