PurposeThe prostate-specific membrane antigen (PSMA) targeted positron-emitting-tomography (PET) tracer 68Ga-PSMA-11 shows great promise in the detection of prostate cancer. However, 68Ga has several shortcomings as a radiolabel including short half-life and non-ideal energies, and this has motivated consideration of 18F-labelled analogs. 18F-PSMA-1007 was selected among several 18F-PSMA-ligand candidate compounds because it demonstrated high labelling yields, outstanding tumor uptake and fast, non-urinary background clearance. Here, we describe the properties of 18F-PSMA-1007 in human volunteers and patients.MethodsRadiation dosimetry of 18F-PSMA-1007 was determined in three healthy volunteers who underwent whole-body PET-scans and concomitant blood and urine sampling. Following this, ten patients with high-risk prostate cancer underwent 18F-PSMA-1007 PET/CT (1 h and 3 h p.i.) and normal organ biodistribution and tumor uptakes were examined. Eight patients underwent prostatectomy with extended pelvic lymphadenectomy. Uptake in intra-prostatic lesions and lymph node metastases were correlated with final histopathology, including PSMA immunostaining.ResultsWith an effective dose of approximately 4.4–5.5 mSv per 200–250 MBq examination, 18F-PSMA-1007 behaves similar to other PSMA-PET agents as well as to other 18F-labelled PET-tracers. In comparison to other PSMA-targeting PET-tracers, 18F-PSMA-1007 has reduced urinary clearance enabling excellent assessment of the prostate. Similar to 18F-DCFPyL and with slightly slower clearance kinetics than PSMA-11, favorable tumor-to-background ratios are observed 2–3 h after injection. In eight patients, diagnostic findings were successfully validated by histopathology. 18F-PSMA-1007 PET/CT detected 18 of 19 lymph node metastases in the pelvis, including nodes as small as 1 mm in diameter.Conclusion 18F-PSMA-1007 performs at least comparably to 68Ga-PSMA-11, but its longer half-life combined with its superior energy characteristics and non-urinary excretion overcomes some practical limitations of 68Ga-labelled PSMA-targeted tracers.Electronic supplementary materialThe online version of this article (doi:10.1007/s00259-016-3573-4) contains supplementary material, which is available to authorized users.

PurposeSince the clinical introduction of 68Ga-PSMA-11 PET/CT, this imaging method has rapidly spread and is now regarded as a significant step forward in the diagnosis of recurrent prostate cancer (PCa). The aim of this study was to analyse the influence of several variables with possible influence on PSMA ligand uptake in a large cohort.MethodsWe performed a retrospective analysis of 1007 consecutive patients who were scanned with 68Ga-PSMA-11 PET/CT (1 h after injection) from January 2014 to January 2017 to detect recurrent disease. Patients with untreated primary PCa or patients referred for PSMA radioligand therapy were excluded. The possible effects of different variables including PSA level and PSA doubling time (PSADT), PSA velocity (PSAVel), Gleason score (GSC, including separate analysis of GSC 7a and 7b), ongoing androgen deprivation therapy (ADT), patient age and amount of injected activity were evaluated.ResultsIn 79.5% of patients at least one lesion with characteristics suggestive of recurrent PCa was detected. A pathological (positive) PET/CT scan was associated with PSA level and ADT. GSC, amount of injected activity, patient age, PSADT and PSAVel were not associated with a positive PET/CT scan in multivariate analysis.Conclusion 68Ga-PSMA-11 PET/CT detects tumour lesions in a high percentage of patients with recurrent PCa. Tumour detection is clearly associated with PSA level and ADT. Only a tendency for an association without statistical significance was found between higher GSC and a higher probability of a pathological PET/CT scan. No associations were found between a pathological 68Ga-PSMA-11 PET/CT scan and patient age, amount of injected activity, PSADT or PSAVel. Electronic supplementary materialThe online version of this article (doi:10.1007/s00259-017-3711-7) contains supplementary material, which is available to authorized users.

The detection of prostate cancer lesions by PET imaging of the prostate-specific membrane antigen (PSMA) has gained highest clinical impact during the last years. 68Ga-labelled Glu-urea-Lys(Ahx)-HBED-CC ([68Ga]Ga-PSMA-HBED-CC) represents a successful novel PSMA inhibitor radiotracer which has recently demonstrated its suitability in individual first-in-man studies. The radiometal chelator HBED-CC used in this molecule represents a rather rarely used acyclic complexing agent with chemical characteristics favourably influencing the biological functionality of the PSMA inhibitor. The simple replacement of HBED-CC by the prominent radiometal chelator DOTA was shown to dramatically reduce the in vivo imaging quality of the respective 68Ga-labelled PSMA-targeted tracer proving that HBED-CC contributes intrinsically to the PSMA binding of the Glu-urea-Lys(Ahx) pharmacophore. Owing to the obvious growing clinical impact, this work aims to reflect the properties of HBED-CC as acyclic radiometal chelator and presents novel preclinical data and relevant aspects of the radiopharmaceutical production process of [68Ga]Ga-PSMA-HBED-CC.