title: 90Y Bremsstrahlung imaging for absorbed-dose assessment in high-dose radioimmunotherapy.
abstract: This feasibility study demonstrates (90)Y quantitative bremsstrahlung imaging of patients undergoing high-dose myeloablative (90)Y-ibritumomab treatment.
  
  
  METHODS
  The study includes pretherapy (111)In SPECT/CT and planar whole-body (WB) imaging at 7 d and therapy (90)Y SPECT/CT at 6 d and (90)Y WB imaging at 1 d. Time-activity curves and organ-absorbed doses derived from (90)Y SPECT images were compared with pretherapy (111)In estimates. Organ activities derived from (90)Y WB images at the first day were compared with corresponding pretherapy estimates.
  
  
  RESULTS
  Pretherapy (111)In images from 3 patients were similar to the (90)Y images. Differences between absorbed-dose estimates from pretherapy (111)In and (90)Y therapy were within 25%, except for the lungs. Corresponding activity differences derived from WB images were within 25%. Differences were ascribed to incomplete compensation methods and real differences in pharmacokinetics between pretherapy and therapy.
  
  
  CONCLUSIONS
  Quantitative bremsstrahlung imaging to estimate organ activities and absorbed doses is feasible.
authors.affiliation: Department of Medical Radiation Physics, Clinical Sciences, Lund University, Lund, Sweden. david.minarik@med.lu.se
authors.forename: David
authors.initials: D
authors.lastname: Minarik
authors.forename: Katarina
authors.initials: K
authors.lastname: Sjögreen-Gleisner
authors.forename: Ola
authors.initials: O
authors.lastname: Linden
authors.forename: Karin
authors.initials: K
authors.lastname: Wingårdh
authors.forename: Jan
authors.initials: J
authors.lastname: Tennvall
authors.forename: Sven-Erik
authors.initials: SE
authors.lastname: Strand
authors.forename: Michael
authors.initials: M
authors.lastname: Ljungberg
mesh_terms: D000368:Aged; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D058846:Antibodies, Monoclonal, Murine-Derived / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use; D016026:Bone Marrow Transplantation; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007205:Indium Radioisotopes; D008297:Male; D008875:Middle Aged; D016499:Radioimmunotherapy / Q000379:methods*; D011874:Radiometry; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D000069283:Rituximab; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon; D014915:Whole-Body Counting; D015021:Yttrium Radioisotopes
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents; D007205:Indium Radioisotopes; D019275:Radiopharmaceuticals; D015021:Yttrium Radioisotopes; D000069283:Rituximab; C422802:ibritumomab tiuxetan