PT  - JOURNAL ARTICLE
AU  - Damian Wild
AU  - Melpomeni Fani
AU  - Richard Fischer
AU  - Luigi Del Pozzo
AU  - Felix Kaul
AU  - Simone Krebs
AU  - Richard Fischer
AU  - Jean E.F. Rivier
AU  - Jean Claude Reubi
AU  - Helmut R. Maecke
AU  - Wolfgang A. Weber
TI  - Comparison of Somatostatin Receptor Agonist and Antagonist for Peptide Receptor Radionuclide Therapy: A Pilot Study
AID  - 10.2967/jnumed.114.138834
DP  - 2014 Aug 01
TA  - Journal of Nuclear Medicine
PG  - 1248--1252
VI  - 55
IP  - 8
4099  - http://jnm.snmjournals.org/content/55/8/1248.short
4100  - http://jnm.snmjournals.org/content/55/8/1248.full
SO  - J Nucl Med2014 Aug 01; 55
AB  - Preclinical and clinical studies have indicated that somatostatin receptor (sst)–expressing tumors demonstrate higher uptake of radiolabeled sst antagonists than of sst agonists. In 4 consecutive patients with advanced neuroendocrine tumors, we evaluated whether treatment with 177Lu-labeled sst antagonists is feasible. Methods: After injection of approximately 1 GBq of 177Lu-DOTA-[Cpa-c(DCys-Aph(Hor)-DAph(Cbm)-Lys-Thr-Cys)-DTyr-NH2] (177Lu-DOTA-JR11) and 177Lu-DOTATATE, 3-dimensional voxel dosimetry analysis based on SPECT/CT was performed. A higher tumor-to-organ dose ratio for 177Lu-DOTA-JR11 than for 177Lu-DOTATATE was the prerequisite for treatment with 177Lu-DOTA-JR11. Results: Reversible minor adverse effects of 177Lu-DOTA-JR11 were observed. 177Lu-DOTA-JR11 showed a 1.7–10.6 times higher tumor dose than 177Lu-DOTATATE. At the same time, the tumor-to-kidney and tumor–to–bone marrow dose ratio was 1.1–7.2 times higher. All 4 patients were treated with 177Lu-DOTA-JR11, resulting in partial remission in 2 patients, stable disease in 1 patient, and mixed response in the other patient. Conclusion: Treatment of neuroendocrine tumors with radiolabeled sst antagonists is clinically feasible and may have a significant impact on peptide receptor radionuclide therapy.