RT Journal Article
SR Electronic
T1 68Ga-PSMA-11 prepared with the Telix kit versus a traditional synthesiser: does it matter?
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1463
OP 1463
VO 62
IS supplement 1
A1 Andreas Vogg
A1 Agnieszka Morgenroth
A1 Felix Mottaghy
A1 Geoffroy Kaisin
A1 Françoise Bruyere
A1 Laura Ravasi
A1 Mohsen Beheshti
YR 2021
UL http://jnm.snmjournals.org/content/62/supplement_1/1463.abstract
AB 1463Background: Gallium labelled radiotracers have gained more impact in clinical PET imaging. Preparing these PET radiotracers on demand by means of kits would allow to increase operating flexibility and the ability to adapt to different hospital structures. In this in vitro study we aimed at investigating the internalization behavior of two different [68Ga]Ga-PSMA-11 preparations - either produced via a traditional synthesizer (Scintomics) at 95°C or with the Telix Kit at room temperature - in PSMA positive and negative cells. The two preparations differ in their isomeric pattern and therefore could potentially behave differently. Methods: LNCaP cells (PSMA+) and PC3 cells (PSMA-) were incubated in triplicate with both preparations of [68Ga]Ga-PSMA-11 (AMNI and scint, 0.5 MBq/well each), with or without a specific inhibitor of PSMA for 15, 30, 45, or 60 min at 37°C and 5% CO2. After stopping cell uptake with cold PBS, cell membrane/surface bound [68Ga]Ga-PSMA-11 as well as the internalized fraction of [68Ga]Ga-PSMA-11 were extracted and counted by a gamma-counter. A linear model was fitted to the data to determine whether the cellular binding and internalization in percent of injected dose/well (%ID/well) of the two different preparations of [68Ga]Ga-PSMA-11 were the same or not. Results: Comparison of the %ID/well showed that cellular binding and internalization of both the Scintomics and Telix (ANMI) Kit preparations of [68Ga]Ga-PSMA-11 was markedly greater in LNCaP cells (top graph) than in PC3 cells (bottom graph). The tests to compare the linear model fitted to the %ID data obtained with the ANMI product to that obtained with the synthesizer across both cell lines showed no P-value of less than 0.05 (Table). Thus, the data is supportive of no difference between the two products in all the sample types across each cell line. Conclusions: [68Ga]Ga-PSMA-11 prepared at room temperature with the Telix Kit has PSMA binding propreties that do not significantly differ from those of the tracer produced at 95C° with a traditional synthesizer. Consequently, the PET imaging characteristics of the tracer prepared with the Telix Kit are not expected to differ from those of the synthesizer prepared tracer.