Send to

Choose Destination
J Nucl Med. 2016 May;57(5):799-804. doi: 10.2967/jnumed.115.166330. Epub 2016 Jan 21.

Noninvasive Imaging of Islet Transplants with 111In-Exendin-3 SPECT/CT.

Author information

Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands.


Islet transplantation is a promising treatment for type 1 diabetic patients. However, there is acute as well as chronic loss of islets after transplantation. A noninvasive imaging method that could monitor islet mass might help to improve transplantation outcomes. In this study, islets were visualized after transplantation in a rat model with a dedicated small-animal SPECT scanner by targeting the glucagonlike peptide-1 receptor (GLP-1R), specifically expressed on β-cells, with (111)In-labeled exendin-3.


Targeting of (111)In-exendin-3 to GLP-1R was tested in vitro on isolated islets of WAG/Rij rats. For in vivo evaluation, 400 or 800 islets were transplanted into the calf muscle of WAG/Rij rats (6-8 wk old). Four weeks after transplantation, SPECT/CT images were acquired 1 h after injection of (111)In-labeled exendin-3. After SPECT acquisition, the muscles containing the transplant were analyzed immunohistochemically and autoradiographically.


The binding assay, performed on isolated islets, showed a linear correlation between the number of islets and (111)In-exendin-3 accumulation (Pearson r = 0.98). In vivo, a 1.70 ± 0.44-fold difference in tracer uptake between 400 and 800 transplanted islets was observed. Ex vivo analysis of the islet transplant showed colocalization of tracer accumulation on autoradiography, with insulin-positive cells and GLP-1R expression on immunohistochemistry.


(111)In-exendin-3 accumulates specifically in the β-cells after islet transplantation and is a promising tracer for noninvasive monitoring of the islet mass.


GLP-1R; SPECT; exendin-3; islet imaging; islet transplantation

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center