90Y Bremsstrahlung imaging for absorbed-dose assessment in high-dose radioimmunotherapy

J Nucl Med. 2010 Dec;51(12):1974-8. doi: 10.2967/jnumed.110.079897. Epub 2010 Nov 15.


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.

Conclusion: Quantitative bremsstrahlung imaging to estimate organ activities and absorbed doses is feasible.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Antibodies, Monoclonal / therapeutic use
  • Antibodies, Monoclonal, Murine-Derived / therapeutic use
  • Antineoplastic Agents / therapeutic use
  • Bone Marrow Transplantation
  • Dose-Response Relationship, Radiation
  • Female
  • Humans
  • Image Interpretation, Computer-Assisted
  • Indium Radioisotopes
  • Male
  • Middle Aged
  • Radioimmunotherapy / methods*
  • Radiometry
  • Radiopharmaceuticals* / therapeutic use
  • Rituximab
  • Tissue Distribution
  • Tomography, Emission-Computed
  • Tomography, Emission-Computed, Single-Photon
  • Whole-Body Counting
  • Yttrium Radioisotopes*


  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Murine-Derived
  • Antineoplastic Agents
  • Indium Radioisotopes
  • Radiopharmaceuticals
  • Yttrium Radioisotopes
  • Rituximab
  • ibritumomab tiuxetan