title: Optimisation of fluorescence guidance during robot-assisted laparoscopic sentinel node biopsy for prostate cancer.
abstract: BACKGROUND
  The hybrid tracer was introduced to complement intraoperative radiotracing towards the sentinel nodes (SNs) with fluorescence guidance.
  
  
  OBJECTIVE
  Improve in vivo fluorescence-based SN identification for prostate cancer by optimising hybrid tracer preparation, injection technique, and fluorescence imaging hardware.
  
  
  METHODS
  Forty patients with a Briganti nomogram-based risk >10% of lymph node (LN) metastases were included. After intraprostatic tracer injection, SN mapping was performed (lymphoscintigraphy and single-photon emission computed tomography with computed tomography (SPECT-CT)). In groups 1 and 2, SNs were pursued intraoperatively using a laparoscopic gamma probe followed by fluorescence imaging (FI). In group 3, SNs were initially located via FI. Compared with group 1, in groups 2 and 3, a new tracer formulation was introduced that had a reduced total injected volume (2.0 ml vs. 3.2 ml) but increased particle concentration. For groups 1 and 2, the Tricam SLII with D-Light C laparoscopic FI (LFI) system was used. In group 3, the LFI system was upgraded to an Image 1 HUB HD with D-Light P system.
  
  
  METHODS
  Hybrid tracer-based SN biopsy, extended pelvic lymph node dissection, and robot-assisted radical prostatectomy.
  
  
  METHODS
  Number and location of the preoperatively identified SNs, in vivo fluorescence-based SN identification rate, tumour status of SNs and LNs, postoperative complications, and biochemical recurrence (BCR).
  
  
  CONCLUSIONS
  Mean fluorescence-based SN identification improved from 63.7% (group 1) to 85.2% and 93.5% for groups 2 and 3, respectively (p=0.012). No differences in postoperative complications were found. BCR occurred in three pN0 patients.
  
  
  CONCLUSIONS
  Stepwise optimisation of the hybrid tracer formulation and the LFI system led to a significant improvement in fluorescence-assisted SN identification. Preoperative SPECT-CT remained essential for guiding intraoperative SN localisation.
  
  
  RESULTS
  Intraoperative fluorescence-based SN visualisation can be improved by enhancing the hybrid tracer formulation and laparoscopic fluorescence imaging system.
authors.affiliation: Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands; Department of Nuclear Medicine, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Gijs H
authors.initials: GH
authors.lastname: KleinJan
authors.affiliation: Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands; Department of Urology, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Nynke S
authors.initials: NS
authors.lastname: van den Berg
authors.affiliation: Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands; Department of Urology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Oscar R
authors.initials: OR
authors.lastname: Brouwer
authors.affiliation: Department of Pathology, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Jeroen
authors.initials: J
authors.lastname: de Jong
authors.affiliation: Acibadem University School of Medicine, Department of Urology, Istanbul, Turkey.
authors.forename: Cenk
authors.initials: C
authors.lastname: Acar
authors.affiliation: Department of Urology, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Esther M
authors.initials: EM
authors.lastname: Wit
authors.affiliation: Department of Nuclear Medicine, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: Vegt
authors.affiliation: Department of Biometrics, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Vincent
authors.initials: V
authors.lastname: van der Noort
authors.affiliation: Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands; Department of Nuclear Medicine, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Renato A
authors.initials: RA
authors.lastname: Valdés Olmos
authors.affiliation: Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands; Department of Urology, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Fijs W B
authors.initials: FW
authors.lastname: van Leeuwen
authors.affiliation: Department of Urology, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands. Electronic address: h.vd.poel@nki.nl.
authors.forename: Henk G
authors.initials: HG
authors.lastname: van der Poel
mesh_terms: D000368:Aged; D004396:Coloring Agents; D005453:Fluorescence; D006801:Humans; D061705:Image-Guided Biopsy / Q000379:methods*; D007208:Indocyanine Green; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D061305:Lymphoscintigraphy; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D061848:Optical Imaging / Q000295:instrumentation / Q000379:methods*; D010388:Pelvis; D011471:Prostatic Neoplasms / Q000473:pathology / Q000601:surgery*; D019275:Radiopharmaceuticals; D065287:Robotic Surgical Procedures; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D013668:Technetium Tc 99m Aggregated Albumin; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed
chemical_list: D004396:Coloring Agents; D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin; C083602:technetium Tc 99m nanocolloid; D007208:Indocyanine Green
keywords: Fluorescence-guided surgery; Hybrid approach; Hybrid tracer; Image-guided surgery; Prostate cancer; Radio-guided surgery; Sentinel (lymph) node