Intra-individual comparison of 68Ga-PSMA-11 and 18F-DCFPyL normal-organ biodistribution

Cancer Imaging

Gonçalo Ferreira¹  Amir Iravani²  Rodney J. Hicks³  Michael S. Hofman³ 

[1] 0000 0004 0631 0608, grid.418711.a, Nuclear Medicine Department, Instituto Português de Oncologia do Porto, Rua Dr. António Bernardino de Almeida, 4200-072, Porto, Portugal;0000000403978434, grid.1055.1, Centre for Molecular Imaging, Department of Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia;0000000403978434, grid.1055.1, Centre for Molecular Imaging, Department of Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia;0000000403978434, grid.1055.1, Centre for Molecular Imaging, Department of Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia;0000 0001 2179 088X, grid.1008.9, Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria, Australia;

关键词: F-DCFPyL;    Ga-PSMA-11;    PET/CT;    Biodistribution;    Prostate cancer;   

DOI  :  10.1186/s40644-019-0211-y

来源: publisher

【 摘 要 】

PurposeDetailed data comparing the biodistribution of PSMA radioligands is still scarce, raising concerns regarding the comparability of different compounds. We investigated differences in normal-organ biodistribution and uptake variability between the two most commonly PSMA tracers in clinical use, 68Ga-PSMA-11 and 18F-DCFPyL.MethodsThis retrospective analysis included 34 patients with low tumor burden referred for PET/CT imaging with 68Ga-PSMA-11 and subsequently 18F-DCFPyL. Images were acquired with 4 cross-calibrated PET/CT systems. Volumes of interest were placed on major salivary and lacrimal glands, liver, spleen, duodenum, kidneys, bladder, blood-pool and muscle. Normal-organ biodistribution of both tracers was then quantified as SUVpeak and compared using paired tests, linear regression and Bland-Altman analysis. Between-patient variability was also assessed. Clinical and protocol variables were investigated for possible interference.ResultsFor both tracers the highest uptake was found in the kidneys and bladder and low background activity was noted across all scans. In the quantitative analysis there was significantly higher uptake of 68Ga-PSMA-11 in the kidneys, spleen and major salivary glands (p <  0.001), while the liver exhibited slightly higher 18F-DCFPyL uptake (p = 0.001, mean bias 0.79 ± 1.30). The lowest solid-organ uptake variability was found in the liver (COV 21.9% for 68Ga-PSMA-11, 22.5% for 18F-DCFPyL). There was a weak correlation between 18F-DCFPyL uptake time and liver SUVpeak (r = 0.488, p = 0.003) and, accordingly, patients scanned at later time-points had a larger mean bias between the two tracers’ liver uptake values (0.05 vs 1.46, p = 0.001).ConclusionNormal tissue biodistribution patterns of 68Ga-PSMA-11 and 18F-DCFPyL were similar, despite subtle differences in quantitative values. Liver uptake showed an acceptable intra-patient agreement and low inter-patient variability between the two tracers, allowing its use as a reference organ for thresholding scans in the qualitative comparison of PSMA expression using these different tracers.

【 授权许可】

CC BY