RT Journal Article SR Electronic T1 Nephrotoxicity in Mice After Repeated Imaging Using 111In-Labeled Peptides JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 973 OP 977 DO 10.2967/jnumed.109.074310 VO 51 IS 6 A1 Marleen Melis A1 Erik Vegt A1 Mark W. Konijnenberg A1 Monique de Visser A1 Magda Bijster A1 Marcel Vermeij A1 Eric P. Krenning A1 Otto C. Boerman A1 Marion de Jong YR 2010 UL http://jnm.snmjournals.org/content/51/6/973.abstract AB We determined the renal radiation dose of a series of 111In-labeled peptides using animal SPECT. Because the animals' health deteriorated, renal toxicity was assessed. Methods: Wild-type and megalin-deficient mice were imaged repeatedly at 3- to 6-wk intervals to quantify renal retention after injection of 40–50 MBq of 111In-diethylenetriaminepentaacetic acid–labeled peptides (octreotide, exendin, octreotate, neurotensin, and minigastrin analogs), and the absorbed kidney radiation doses were estimated. Body weight, renal function parameters, and renal histology were determined at 16–20 wk after the first scan and compared with those in naive animals. Results: Because of high renal retention, 111In-diethylenetriaminepentaacetic acid–exendin-4 scans resulted in a 70-Gy kidney radiation dose in wild-type mice. Megalin-deficient kidneys received 20–40 Gy. The other peptides resulted in much lower renal doses. Kidney function monitoring indicated renal damage in imaged animals. Conclusion: Micro-SPECT enables longitudinal studies in 1 animal. However, long-term nephrotoxic effects may be induced after high renal radiation doses, even with 111In-labeled radiotracers.