RT Journal Article SR Electronic T1 90Y Bremsstrahlung Imaging for Absorbed-Dose Assessment in High-Dose Radioimmunotherapy JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1974 OP 1978 DO 10.2967/jnumed.110.079897 VO 51 IS 12 A1 Minarik, David A1 Sjögreen-Gleisner, Katarina A1 Linden, Ola A1 Wingårdh, Karin A1 Tennvall, Jan A1 Strand, Sven-Erik A1 Ljungberg, Michael YR 2010 UL http://jnm.snmjournals.org/content/51/12/1974.abstract AB This feasibility study demonstrates 90Y quantitative bremsstrahlung imaging of patients undergoing high-dose myeloablative 90Y-ibritumomab treatment. Methods: The study includes pretherapy 111In SPECT/CT and planar whole-body (WB) imaging at 7 d and therapy 90Y SPECT/CT at 6 d and 90Y WB imaging at 1 d. Time–activity curves and organ-absorbed doses derived from 90Y SPECT images were compared with pretherapy 111In estimates. Organ activities derived from 90Y WB images at the first day were compared with corresponding pretherapy estimates. Results: Pretherapy 111In images from 3 patients were similar to the 90Y images. Differences between absorbed-dose estimates from pretherapy 111In and 90Y 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.