Recently, prostate-specific membrane antigen (PSMA) targeted PET-imaging has emerged as new method of staging and restaging of prostate cancer. Most published studies have investigated the diagnostic potential of Ga-labeled PSMA-agents which are excreted renally. [F]PSMA-1007 is a novel PSMA-ligand with excellent preclinical characteristics which is only minimally excreted by the urinary tract, a potential advantage for pelvic imaging. The aim of this study was to investigate the diagnostic efficacy of [F]PSMA-1007 in biochemical recurrence (BCR) after radical prostatectomy (RP). 251 patients from three academic centers with BCR after radical prostatectomy were evaluated in a retrospective analysis. Patients who had received second line androgen deprivation therapy and/or chemotherapy were excluded, however prior first line ADT exposure was allowed. The median PSA-level was 1.2 ng/ml (range: 0.2-228 ng/mL). All patients underwent a PSMA-PET/CT after injection of 301±46 MBq [F]PSMA-1007 at 92±26 min post injection. The detection rate of presumed recurrence sites was correlated with PSA-level and original primary Gleason score. A comparison to a subset of patients treated previously with androgen deprivation therapy (ADT) was undertaken. 204 of 251 patients (81.3%) patients had evidence of recurrence on [F]PSMA-1007 PET/CT. The detection rates were 94.1% (79/84), 90.1% (50/55), 74.5% (35/47) and 61.5% (40/65) for PSA-levels of ≥2, 1-<2, 0.5-<1 and 0.2-<0.5ng/mL, respectively. [F]PSMA-1007 PET/CT revealed local recurrence in 43.7% (62) of patients. Lymph node metastases were present in the pelvis in 40.6% (102), in the retroperitoneum in 19.5% (49) and in supradiaphragmatic locations in 12.0% (30) of patients. Bone and visceral metastases were detected in 40.2% (101) and 3.6% (9) patients. In higher Gleason score tumors (≤7vs.≥8) detection efficacy trended higher (76.3% vs. 86.7%) but was not statistically significant ( = 0.32). However, detection efficacy was higher in patients who had previously been on ADT (91.7% vs. 78.0%) within 6 months prior to imaging ( = 0.0179). [F]PSMA-1007 PET/CT offers high detection rates in BCR after radical prostatectomy which is comparable to or better than that published for Ga-labelled PSMA-ligands.

Prostate specific membrane antigen (PSMA)-ligand PET/CT is performed in patients with prostate cancer to stage the disease initially or to identify sites of recurrence after definitive therapy. 18 F-PSMA-1007 is a promising PSMA-PET tracer based on clinical results, but detailed histologic confirmation has been lacking.

Aims: The diagnosis of deep seated bacterial infections, such as intra-abdominal abscesses, endocarditis, and osteomyelitis, can be difficult and delayed, thereby compromising effective treatment. This study assessed the efficacy of a new radioimaging agent, Tc-99m ciprofloxacin (Infecton), in accurately detecting sites of bacterial infection. Methods: Eight hundred and seventy nine patients with suspected bacterial infection underwent Infecton imaging and microbiological evaluation. The sensitivity and specificity of Infecton in detecting sites of bacterial infection were determined with respect to Centres of Disease Control, World Health Organisation, and Dukes's criteria. Results: Five hundred and seventy four positive and 295 negative images were produced. These included 528 true positives, 46 false positives, 205 true negatives and 90 false negatives, giving an overall sensitivity of 85.4% and a specificity of 81.7% for detecting infective foci. Sensitivity was higher (87.6%) in microbiologically confirmed infections. Conclusions: Infecton is a sensitive technique, which aids in the earlier detection and treatment of a wide variety of deep seated bacterial infections. The ability to localise infective foci accurately is also important for surgical intervention, such as drainage of abscesses. In addition, serial imaging with Infecton might be useful in monitoring clinical response and optimising the duration of antimicrobial treatment.

Introduction PSMA-targeted radionuclide therapy with lutetium-177 has emerged as an effective treatment option for metastatic, castration-resistant prostate cancer (mCRPC). Recently, the concept of modifying PSMA radioligands with an albumin-binding entity was demonstrated as a promising measure to increase the tumor uptake in preclinical experiments. The aim of this study was to translate the concept to a clinical setting and evaluate the safety and dosimetry of [177Lu]Lu-PSMA-ALB-56, a novel PSMA radioligand with albumin-binding properties. Methods Ten patients (71.8 ± 8.2 years) with mCRPC received an activity of 3360 ± 393 MBq (120–160 μg) [177Lu]Lu-PSMA-ALB-56 followed by whole-body SPECT/CT imaging over 7 days. Volumes of interest were defined on the SPECT/CT images for dosimetric evaluation for healthy tissue and tumor lesions. General safety and therapeutic efficacy were assessed by measuring blood biomarkers. Results [177Lu]Lu-PSMA-ALB-56 was well tolerated, and no severe adverse events were observed. SPECT images revealed longer circulation of [177Lu]Lu-PSMA-ALB-56 in the blood with the highest uptake in tumor lesions at 48 h post injection. Compared with published data for other therapeutic PSMA radioligands (e.g. PSMA-617 and PSMA I&T), normalized absorbed doses of [177Lu]Lu-PSMA-ALB-56 were up to 2.3-fold higher in tumor lesions (6.64 ± 6.92 Gy/GBq) and similar in salivary glands (0.87 ± 0.43 Gy/GBq). Doses to the kidneys and red marrow (2.54 ± 0.94 Gy/GBq and 0.29 ± 0.07 Gy/GBq, respectively) were increased. Conclusion Our data demonstrated that the concept of albumin-binding PSMA-radioligands is feasible and leads to increased tumor doses. After further optimization of the ligand design, the therapeutic outcomes may be improved for patients with prostate cancer.