PT - JOURNAL ARTICLE AU - Isabel Rauscher AU - Wolfgang P. Fendler AU - Thomas A. Hope AU - Andrew Quon AU - Stephan G. Nekolla AU - Jeremie Calais AU - Antonia Richter AU - Bernhard Haller AU - Ken Herrmann AU - Wolfgang A. Weber AU - Johannes Czernin AU - Matthias Eiber TI - Can the Injected Dose Be Reduced in <sup>68</sup>Ga-PSMA-11 PET/CT While Maintaining High Image Quality for Lesion Detection? AID - 10.2967/jnumed.119.227207 DP - 2020 Feb 01 TA - Journal of Nuclear Medicine PG - 189--193 VI - 61 IP - 2 4099 - http://jnm.snmjournals.org/content/61/2/189.short 4100 - http://jnm.snmjournals.org/content/61/2/189.full SO - J Nucl Med2020 Feb 01; 61 AB - Our purpose was to define a clinically useful lower limit of injected dose for 68Ga-prostate-specific membrane antigen (PSMA)-11 PET/CT imaging of prostate cancer. Methods: 68Ga-PSMA-11 PET/CT was performed on 11 patients. PET was acquired in list mode and reconstructed using a 3-min full acquisition, a 2-min acquisition, and a 1-min acquisition to generate images obtained with three thirds (standard dose), two thirds (low dose), and one third (very low dose) of the injected dose, respectively. Overall image quality (5-point scale) was assessed, and the detectability of PSMA-positive lesions was determined by 3 readers and compared with the reference standard. Results: Image quality declined with decreasing dose (mean score of 4.1 ± 0.4 for the standard dose, 3.4 ± 0.7 for the low dose, and 1.9 ± 0.4 for the very low dose; all P &lt; 0.05). Readers 1, 2, and 3 correctly identified the lesions (n = 21) at a rate of 100%, 100%, and 95% with the standard dose; 95%, 81%, and 90% with the low dose; and 71%, 76%, and 59% with the very low dose, respectively. Conclusion: 68Ga-PSMA-11 dose reduction is not feasible without a negative impact on image quality and lesion detectability.