Estimation of radiation dosimetry for 68 Ga-HBED-CC (PSMA-11) in patients with suspected recurrence of prostate cancer

• Published in: Nuclear medicine and biology 2017-03, Vol.46, p.32
• Main Authors: Green, Mark A, Eitel, Jacob A, Fletcher, James W, Mathias, Carla J, Tann, Mark A, Gardner, Thomas, Koch, Michael O, Territo, Wendy, Polson, Heather, Hutchins, Gary D
• Format: Article
• Language: English
• Subjects: Edetic Acid - analogs & derivatives; Humans; Male; Positron Emission Tomography Computed Tomography; Prostatic Neoplasms - diagnostic imaging; Radiometry; Recurrence
• ISSN: 1872-9614
• DOI: 10.1016/j.nucmedbio.2016.11.002

This study was performed to estimate the human radiation dosimetry for [ Ga]Ga-HBED-CC (PSMA-11) ( Ga PSMA-11). Under an RDRC-approved research protocol, we evaluated the biodistribution and pharmacokinetics of Ga PSMA-11 with serial PET imaging following intravenous administration to nine prostate cancer patients in whom clinical [ C]acetate PET/CT exams had been independently performed under Expanded Access IND 118,204. List-mode imaging was performed over the initial 0-10min post-injection with the pelvis in the field-of-view. Whole-body images were acquired, pelvis-to-head, at 15, 60, and 90-min post-injection. Additional images of the pelvis were acquired at 40-min and 115-min, and voided urine collected from each subject at 48-min and 120-min post-injection. Radiation dosimetry estimates were calculated from these data using the OLINDA software package. Renal uptake was high and relatively invariant, ranging from 11% to 14% of the injected dose between 15 and 90-min post-injection. Radioactivity collected in the voided urine accounted for 14% of the injected dose over a period of 120-min. Lymph nodes and skeletal metastases suspicious for prostate cancer recurrence were detected in a greater number of patients using Ga PSMA-11 than using C-acetate. Kidneys are the critical organ following Ga PSMA-11 administration, receiving an estimated dose of 0.413mGy/MBq. This study confirms that the kidneys will be the critical organ following intravenous administration of Ga PSMA-11, and provided data consistent with the expectation that Ga PSMA-11 will be superior to [ C]acetate for defining sites of recurrence in prostate cancer patients presenting with biochemical relapse.