title: Quantitative and longitudinal imaging of intramuscular transplanted islets of Langerhans with SPECT using [123I]IBZM.
abstract: A non-invasive imaging method to monitor islet grafts could provide novel and improved insight into the fate of transplanted islets and, potentially, monitor the effect of therapeutic interventions. Therefore, such an imaging method could help improve long-term transplantation outcome. Here, we investigated the use of [123I]IBZM for insulin positive graft volume quantification and longitudinal graft monitoring. SPECT images were acquired 6 weeks after islet transplantation in the calf muscle of rats. For longitudinal graft analysis, rats were monitored by SPECT for 10 weeks. After animals were euthanized, graft containing muscles were dissected for ex vivo analysis and insulin-positive graft volume determination. Six weeks after transplantation, a clear signal was observed in all grafts by SPECT imaging. Moreover, the intensity of the SPECT signal correlated linearly with insulin-positive graft volume, as determined histologically. Longitudinal graft follow-up showed a clear SPECT signal of the transplant from 3 until 10 weeks after transplantation. In this study, we demonstrate for the first time the successful application of a radiotracer, [123I]IBZM, for non-invasive, in vivo graft volume quantification and longitudinal graft monitoring.
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Stefanie M A
authors.initials: SM
authors.lastname: Willekens
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Inge
authors.initials: I
authors.lastname: van der Kroon
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Desirée
authors.initials: D
authors.lastname: Bos
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Lieke
authors.initials: L
authors.lastname: Joosten
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Cathelijne
authors.initials: C
authors.lastname: Frielink
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Otto C
authors.initials: OC
authors.lastname: Boerman
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Maarten
authors.initials: M
authors.lastname: Brom
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Martin
authors.initials: M
authors.lastname: Gotthardt
mesh_terms: D000818:Animals; D001549:Benzamides; D003287:Contrast Media; D007515:Islets of Langerhans / Q000000981:diagnostic imaging*; D016381:Islets of Langerhans Transplantation; D035002:Lower Extremity / Q000000981:diagnostic imaging*; D011184:Postoperative Period; D011759:Pyrrolidines; D051381:Rats; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D001549:Benzamides; D003287:Contrast Media; D011759:Pyrrolidines; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide
keywords: beta cell; islets; type 1 diabetes