Variation on PSMA Receptor Expression over time in prostate cancer

Prostate cancer is the third most common cancer in Europe and is still the leading cancer among men in the Netherlands with over 13,000 men diagnosed each year. 68-Gallium Prostate Specific Membrane Antigen (68Ga-PSMA) is an emerging imaging agent that already has been widely proven as a highly effective agent for restaging PCa cells, but also holds enormous potential for initial staging and image guided surgery. During surgery, 68Ga-PSMA can potentially be used for the assessment of resection margins based on Cerenkov Light emission. The interval between initial staging and subsequent prostatectomy surgery, however, ranges from 4 to 6 weeks. Since little is known about the PSMA expression over time without intervention, a study on this is required. If PSMA expression is equal between both scans, the inclusion and dose determination for image guided surgery can be based on the clinical 68Ga-PSMA PET/CT scan. In order to validate this, two PET scans will be performed in a test-retest setting in primary prostate cancer patients. Dynamic imaging will be performed in order to get insight when uptake in the prostate is visible. Subsequently this will be used also to establish the ideal timing of surgery after injection.The objective of this study is to obtain preliminary data on variability in PSMA expression by comparing the tracer uptake on conventional clinical 68Ga-PSMA PET/CT with an additional 68Ga-PSMA PET/CT (4 weeks later) within primary prostate cancer patients. Dynamic imaging will be performed in 5 patients in order to get insight when uptake in the prostate is visible.

We expect that the second measurement will be different from the first measurement by no more than 10%.

Not applicable