European journal of nuclear medicine and molecular imaging
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Eur. J. Nucl. Med. Mol. Imaging · Sep 2017
Early PET imaging with [68]Ga-PSMA-11 increases the detection rate of local recurrence in prostate cancer patients with biochemical recurrence.
PET/CT using 68Ga-labelled prostate-specific membrane antigen PSMA-11 (HBEDD-CC) has emerged as a promising imaging method in the diagnostic evaluation of prostate cancer (PC) patients with biochemical recurrence. However, assessment of local recurrence (LR) may be limited by intense physiologic tracer accumulation in the urinary bladder on whole-body scans, normally conducted 60 min post-tracer injection (p.i.). It could be shown on early dynamic imaging studies that 68Ga-PSMA-11 uptake in PC lesions occurs earlier than tracer accumulation in the urinary bladder. This study aims to investigate whether early static PET acquisition increases detection rate of local recurrence on 68Ga-PSMA-11 PET/CT in comparison to PET imaging 60 min p.i.. ⋯ Performance of early imaging in 68Ga-PSMA-11 PET/CT in addition to whole-body scans 60 min p.i. increases the detection rate of local recurrence in PC patients with biochemical recurrence. Acquisition of early PET images should be started as early as 5 min p.i. in order to avoid disturbing tracer activity in the urinary bladder occuring at a later time point.
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Eur. J. Nucl. Med. Mol. Imaging · Sep 2017
Effects of arm truncation on the appearance of the halo artifact in 68Ga-PSMA-11 (HBED-CC) PET/MRI.
PSMA ligand imaging with hybrid PET/MRI scanners could be an integral part of the clinical routine in the future. However, the first study about this novel method revealed a severe photopenic artifact ("halo artifact") around the urinary bladder causing significantly reduced tumor visibility. The aim of this evaluation was to analyze the role of arm truncation on the appearance of the halo artifact in 68Ga-PSMA-11 PET/MRI hypothesizing that this influences the appearance. ⋯ Positioning the arms down was shown to be significantly associated with the appearance of the halo artifact in PET/MRI. Positioning the arms up above the head can significantly reduce the halo artifact, thereby detecting more tumor lesions.