Impact of Targeted Molecular Imaging with 18F-PSMA-1007 and 68Ga-PSMA-11 PET/CT in Multimodal Evaluation of Recurrent Prostate

Prostate cancer (PCa) is the most common malignant tumor in men in Latvia. More than 1,000 every year get PCa diagnosis. In addition, Baltic states have the highest specific mortality rates for this cancer in Europe. In clinically moderate/high risk PCa recurrence occur up to 30% after radical treatment, therefore imaging of local and distant metastatic sites is of most importance for appropriate treatment selection. It is planned to study the utility of PSMA ligand PET/CT in biochemically recurrent PCa with two tracers: 68-Ga-PSMA-11 and 18-F-PSMA-1007: 1) to specify the imaging biomarkers in recurrent prostate cancer diagnostics, correlating with PSA levels, Gleason score and PSMA ligand PET/CT ability to visualize prostate cancer local recurrence and distant metastases (oligo-metastatic disease); 2) to evaluate the accuracy of PSMA ligand PET/CT tracers: 68Ga-PSMA-11 and 18-F-PSMA-1007 in reference to other imaging modalities (MRI and bone scintigraphy); 3) to define and compare PSA thresholds for effective diagnostic PSMA ligand PET/CT examinations. Multimodality comparative approach of the 68Ga-PSMA and 18F-PSMA-1007 PET/CT study may advance algorithmic selection of tracers and appropriately affect management decisions for patients with prostate cancer, particularly at the time of biochemical recurrence, to facilitate individual treatment planning, assess outcomes, avoiding unnecessary examinations, therefore improving life quality for patients.