title: Sentinel lymph node mapping using SPECT/CT and gamma probe in endometrial cancer: an analysis of parameters affecting detection rate.
abstract: OBJECTIVE
  SPECT/CT after pericervical injection of technetium-99 m-nanocolloid was shown to be suitable for sentinel lymph node (SLN) mapping in endometrial cancer (EC). The aim of this study was to analyze factors affecting successful SLN detection by means of SPECT/CT such as imaging findings, patient characteristics and tumor biology in a large cohort of patients.
  
  
  METHODS
  One hundred and forty-five consecutive patients suffering from EC who received pre-surgical SLN mapping at our institution between 2011 and 2016 were included in this analysis. SPECT/CT data of abdomen and pelvis (mean 4:20 ± 1:20 h p.i.) were acquired after pericervical injection of technetium-99 m-nanocolloid (mean 230 ± 45 MBq) in all patients. Surgical staging was performed on the day after. Acquisition parameters, patient characteristics, SPECT/CT findings as well as histopathological results were collected.
  
  
  RESULTS
  A total of 282 SLNs were identified by means of SPECT/CT. Overall, preoperative and intraoperative SLN detection rates were 86%, 76% and 74% respectively. The most important factor associated with failure to detect SLNs was the presence of high bone marrow on SPECT/CT (p = 0.005). Peritoneal/abdominal radioactivity was also associated with missed SLN detection in SPECT/CT (p = 0.02). However, the presence of liver/spleen uptake on its own was not predictive for detection failure. Low numbers of detected SLNs in SPECT/CT were slightly related with older age and lower injected activity. No significant influence was found for the parameters of tumor histology and stage, lymph node involvement and the time gap between injection and imaging.
  
  
  CONCLUSIONS
  Venous drainage as indicated by bone marrow uptake is the most important factor associated with scintigraphic SLN detection failure. Moreover, high peritoneal and abdominal activity was also associated with detection failure. Thus, meticulous application of the radiotracer is crucial in EC.
authors.affiliation: Nuclear Medicine and Clinical Molecular Imaging, University Hospital Tuebingen, Otfried-Müller-Straße 14, 72076, Tübingen, Germany. sam.sahbai@gmail.com.
authors.forename: Samine
authors.initials: S
authors.lastname: Sahbai
authors.affiliation: Gynecology and Obstetrics, University Hospital Tuebingen, Tuebingen, Germany.
authors.forename: Florin-Andrei
authors.initials: FA
authors.lastname: Taran
authors.affiliation: Pathology, University Hospital Tuebingen, Tuebingen, Germany.
authors.forename: Annette
authors.initials: A
authors.lastname: Staebler
authors.affiliation: Gynecology and Obstetrics, University Hospital Tuebingen, Tuebingen, Germany.
authors.forename: Diethelm
authors.initials: D
authors.lastname: Wallwiener
authors.affiliation: Nuclear Medicine and Clinical Molecular Imaging, University Hospital Tuebingen, Otfried-Müller-Straße 14, 72076, Tübingen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: la Fougère
authors.affiliation: Gynecology and Obstetrics, University Hospital Tuebingen, Tuebingen, Germany.
authors.forename: Sara
authors.initials: S
authors.lastname: Brucker
authors.affiliation: Nuclear Medicine and Clinical Molecular Imaging, University Hospital Tuebingen, Otfried-Müller-Straße 14, 72076, Tübingen, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Dittmann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016889:Endometrial Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D005260:Female; D005720:Gamma Rays; D006801:Humans; D007432:Intraoperative Period; D008875:Middle Aged; D009367:Neoplasm Staging; D021701:Sentinel Lymph Node Biopsy / Q000295:instrumentation / Q000379:methods*; D000072098:Single Photon Emission Computed Tomography Computed Tomography; D013668:Technetium Tc 99m Aggregated Albumin
chemical_list: D013668:Technetium Tc 99m Aggregated Albumin; C083602:technetium Tc 99m nanocolloid
keywords: Detection failure; Endometrial cancer; Lymphoscintigraphy; Nanocolloid; SPECT/CT; Sentinel lymph node