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BioMed Research International
Volume 2013 (2013), Article ID 935351, 12 pages
http://dx.doi.org/10.1155/2013/935351
Clinical Study

Kidney Dosimetry in 177Lu and 90Y Peptide Receptor Radionuclide Therapy: Influence of Image Timing, Time-Activity Integration Method, and Risk Factors

1Medical Physics Department, European Institute of Oncology, 20141 Milan, Italy
2Medical Physics Department, IRCCS Arcispedale Santa Maria Nuova, 42123 Reggio Emilia, Italy
3Nuclear Medicine Department, IRCCS Arcispedale Santa Maria Nuova, 42123 Reggio Emilia, Italy
4Medical Physics Department, IRCCS Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori, 47014 Meldola, Italy
5Medical Physics Department, Azienda Ospedaliera S. Camillo Forlanini, 00151 Rome, Italy
6Section of Radiological Sciences, Department of Biomedical Sciences and Morphologic and Functional Imaging, University of Messina, 98125 Messina, Italy
7Laboratory of Medical Physics and Expert Systems, National Cancer Institute Regina Elena, 00144 Rome, Italy
8Nuclear Medicine Department, European Institute of Oncology, 20141 Milan, Italy

Received 30 April 2013; Accepted 31 May 2013

Academic Editor: David J. Yang

Copyright © 2013 F. Guerriero et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Kidney dosimetry in 177Lu and 90Y PRRT requires 3 to 6 whole-body/SPECT scans to extrapolate the peptide kinetics, and it is considered time and resource consuming. We investigated the most adequate timing for imaging and time-activity interpolating curve, as well as the performance of a simplified dosimetry, by means of just 1-2 scans. Finally the influence of risk factors and of the peptide (DOTATOC versus DOTATATE) is considered. 28 patients treated at first cycle with 177Lu DOTATATE and 30 with 177Lu DOTATOC underwent SPECT scans at 2 and 6 hours, 1, 2, and 3 days after the radiopharmaceutical injection. Dose was calculated with our simplified method, as well as the ones most used in the clinic, that is, trapezoids, monoexponential, and biexponential functions. The same was done skipping the 6 h and the 3 d points. We found that data should be collected until 100 h for 177Lu therapy and 70 h for 90Y therapy, otherwise the dose calculation is strongly influenced by the curve interpolating the data and should be carefully chosen. Risk factors (hypertension, diabetes) cause a rather statistically significant 20% increase in dose ( -test, ), with DOTATATE affecting an increase of 25% compared to DOTATOC ( -test, ).