title: Usefulness and pitfalls of MAA SPECT/CT in identifying digestive extrahepatic uptake when planning liver radioembolization.
abstract: OBJECTIVE
  Identifying gastroduodenal uptake of (99m)Tc-macroaggregated albumin (MAA), which is associated with an increased risk of ulcer disease, is a crucial part of the therapeutic management of patients undergoing radioembolization for liver tumours. Given this context, the use of MAA single photon emission computed tomography (SPECT)/CT may be essential, but the procedure has still not been thoroughly evaluated. The aim of this retrospective study was to determine the effectiveness of MAA SPECT/CT in identifying digestive extrahepatic uptake, while determining potential diagnostic pitfalls.
  
  
  METHODS
  Overall, 139 MAA SPECT/CT scans were performed on 103 patients with different hepatic tumour types. Patients were followed up for at least 6 months according to standard requirements.
  
  
  RESULTS
  Digestive, or digestive-like, uptake other than free pertechnetate was identified in 5.7% of cases using planar imaging and in 36.6% of cases using SPECT/CT. Uptake sites identified by SPECT/CT included the gastroduodenal region (3.6%), gall bladder (12.2%), portal vein thrombosis (6.5%), hepatic artery (6.5%), coil embolization site (2.1%) as well as falciform artery (5.0%). For 2.1% of explorations, a coregistration error between SPECT and CT imaging could have led to a false diagnosis by erroneously attributing an uptake site to the stomach or gall bladder, when the uptake actually occurred in the liver.
  
  
  CONCLUSIONS
  SPECT/CT is more efficacious than planar imaging in identifying digestive extrahepatic uptake sites, with extrahepatic uptake observed in one third of scans using the former procedure. However, more than half of the uptake sites in our study were vascular in nature, without therapeutic implications. The risk of coregistration errors must also be kept in mind.
authors.affiliation: Department of Nuclear Medicine, Comprehensive Cancer Institute Eugène Marquis, CS 44229, 35042 Rennes, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Lenoir
authors.forename: Julien
authors.initials: J
authors.lastname: Edeline
authors.forename: Yann
authors.initials: Y
authors.lastname: Rolland
authors.forename: Marc
authors.initials: M
authors.lastname: Pracht
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Raoul
authors.forename: Valérie
authors.initials: V
authors.lastname: Ardisson
authors.forename: Patrick
authors.initials: P
authors.lastname: Bourguet
authors.forename: Bruno
authors.initials: B
authors.lastname: Clément
authors.forename: Eveline
authors.initials: E
authors.lastname: Boucher
authors.forename: Etienne
authors.initials: E
authors.lastname: Garin
mesh_terms: D000368:Aged; D001692:Biological Transport; D004064:Digestive System / Q000378:metabolism*; D004621:Embolization, Therapeutic / Q000009:adverse effects; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000532:radiotherapy*; D008297:Male; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D012189:Retrospective Studies; D013438:Sulfhydryl Compounds / Q000009:adverse effects / Q000378:metabolism*; D013668:Technetium Tc 99m Aggregated Albumin / Q000009:adverse effects / Q000378:metabolism*; D014057:Tomography, X-Ray Computed; D014456:Ulcer / Q000209:etiology / Q000378:metabolism
chemical_list: D013438:Sulfhydryl Compounds; D013668:Technetium Tc 99m Aggregated Albumin; C082426:technetium Tc99m-mercaptoacetyl albumin