We studied the effect of varying specific activity of [68Ga]DKFZ-PSMA11 ([68Ga]DP11) on repeated imaging of prostate-specific membrane antigen-positive (PSMA+) xenograft tumors.
Athymic nude mice bearing PC3-PIP (PSMA+) and PC3 (PSMA-) bilateral flank tumors were assessed to study intra- and inter-day repeatability of [68Ga]DP11 imaging in mice administered [68Ga]DP11 or [67Ga]DP11 (as a dilution tracer) using imaging and biodistribution studies.
Region of interest (ROI) analysis of the [68Ga]DP11 imaging study indicated that the uptake was constant on the same day or consecutive days. Prior imaging with [68Ga]DP11 did not significantly influence the subsequent uptake of [68Ga]DP11. Uptake of [68Ga]DP11 (60 min) and [67Ga]DP11 (24 h) in PC3-PIP tumors was 12.37 ± 4.19 %ID/g and 12.49 ± 6.88 %ID/g, respectively; [68Ga]DP11 was 13.83 ± 3.77 and 17.76 ± 1.84 on same-day and 15.98 ± 5.82 %ID/g on second-day imaging.
This study demonstrates that [68Ga]DP11, in a given PSMA+ lesion, is constant under several same-day or serial-day imaging conditions.
Molecular imaging and biology. 2017 Dec [Epub]
Joseph R Osborne, Teja M Kalidindi, Blesida J Punzalan, Kishore Gangangari, Daniel E Spratt, Wolfgang A Weber, Steven M Larson, Naga Vara Kishore Pillarsetty
Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Box 77, New York, NY, 10065, USA. ., Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Box 77, New York, NY, 10065, USA., Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, USA.