title: The use of a portable gamma camera for preoperative lymphatic mapping: a comparison with a conventional gamma camera.
abstract: OBJECTIVE
  Planar lymphoscintigraphy is routinely used for preoperative sentinel node visualization, but large gamma cameras are not always available. We evaluated the reproducibility of lymphatic mapping with a smaller and portable gamma camera.
  
  
  METHODS
  In two centres, 52 patients with breast cancer received preoperative lymphoscintigraphy with a conventional gamma camera with a field of view of 40 × 40 cm. Static anterior and lateral images were performed at 15 min, 2 h and 4 h after injection of the radiotracer ((99m)Tc-nanocolloid). At 2 h after injection, anterior and oblique images were also performed with a portable gamma camera (Sentinella, Oncovision) positioned to obtain a field of view of 20 × 20 cm. Visualization of lymphatic drainage on conventional images and images with the portable device were compared for number of nodes depicted, their intensity and localization of sentinel nodes.
  
  
  RESULTS
  The images performed with the conventional gamma camera depicted sentinel nodes in 94%, while the portable gamma camera showed drainage in 73%. There was however no significant difference in visualization between the two devices when a lead shield was used to mask the injection area in 43 patients (95 vs 88%, p = 0.25). Second-echelon nodes were visualized in 62% of the patients with the conventional gamma camera and in 29% of the cases with the portable gamma camera.
  
  
  CONCLUSIONS
  Preoperative imaging with a portable gamma camera fitted with a pinhole collimator to obtain a field of view of 20 × 20 cm is able to depict sentinel nodes in 88% of the cases, if a lead shield is used to mask the injection site. This device may be useful in centres without the possibility to perform a preoperative image.
authors.affiliation: Nuclear Medicine Department (CDIC), Hospital Clinic Barcelona, Villarroel 170, 08036, Barcelona, Spain. svidal@clinic.ub.es
authors.forename: Sergi
authors.initials: S
authors.lastname: Vidal-Sicart
authors.forename: Lenka
authors.initials: L
authors.lastname: Vermeeren
authors.forename: Oriol
authors.initials: O
authors.lastname: Solà
authors.forename: Pilar
authors.initials: P
authors.lastname: Paredes
authors.forename: Renato A
authors.initials: RA
authors.lastname: Valdés-Olmos
mesh_terms: D001692:Biological Transport; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D005240:Feasibility Studies; D015902:Gamma Cameras; D006801:Humans; D057234:Preoperative Period; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy / Q000295:instrumentation*