English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Purpose  Detailed 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,  68 Ga-PSMA-11 and  18 F-DCFPyL.    Methods  This retrospective analysis included 34 patients with low tumor burden referred for PET/CT imaging with  68 Ga-PSMA-11 and subsequently  18 F-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 SUV peak  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.    Results  For 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  68 Ga-PSMA-11 in the kidneys, spleen and major salivary glands ( p  <  0.001), while the liver exhibited slightly higher  18 F-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  68 Ga-PSMA-11, 22.5% for  18 F-DCFPyL). There was a weak correlation between  18 F-DCFPyL uptake time and liver SUV peak  (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).    Conclusion  Normal tissue biodistribution patterns of  68 Ga-PSMA-11 and  18 F-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.    Electronic supplementary material  The online version of this article (10.1186/s40644-019-0211-y) contains supplementary material, which is available to authorized users.

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