TY - JOUR T1 - Reduced Renal Uptake of <sup>68</sup>Ga-PSMA-617 by Penta-L-Glutamic Acid Co-Injection JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1279 LP - 1279 VL - 59 IS - supplement 1 AU - Tomoya Uehara AU - Yukina Minegishi AU - Shouta Kise AU - Shiori Takahashi AU - Hiroyuki Suzuki AU - Yasushi Arano Y1 - 2018/05/01 UR - http://jnm.snmjournals.org/content/59/supplement_1/1279.abstract N2 - 1279Objectives: Radiolabeled asymmetric urea compounds (Glu-urea-based molecule) have been found useful for imaging and treatment of prostate cancer. The reduction of renal accumulation of the radiolabeled urea compounds would increase diagnostic accuracy and therapeutic effectiveness. In this study, we evaluated the effect of penta-L-glutamic acid (Glu5) co-injection on the renal accumulation of 67Ga-PSMA-617 in mice. Methods: 67Ga-PSMA-617 was injected into normal or LNCap tumor-bearing nude mice with or without Glu5 (2.5 mg/mouse) or L-Lysine (35 mg/mouse). At 1 h postinjection, tissue distribution of 67Ga-PSMA-617 in the mice was compared. Results: There observed no significant differences in the renal radioactivity levels between 67Ga-PSMA-617 with and without L-Lysine. On the other hand, the co-injection of Glu5 with 67Ga-PSMA-617 significantly reduced renal radioactivity levels when compared with 67Ga-PSMA-617 without Glu5. In addition, the tumor radioactivity levels remained unchanged following the co-injection of 67Ga-PSMA-617 with Glu5. No significant differences were observed in the radioactivity levels in other tissue. Conclusions: The co-injection of Glu5 would constitute a useful way to reduce renal uptake of 67Ga-PSMA-617 without impairing the radioactivity levels in the tumor. These results also suggested that the renal reabsorption of 67Ga-PSMA-617 at the proximal tubules would be in part responsible for the renal uptake of the compound. ER -