FTT PET/CT in Metastatic Prostate Cancer

Up to 30 evaluable patients with a histological diagnosis of prostate cancer with clinical evidence of metastatic disease who are being considered for new therapy or for a change in therapy with a PARP inhibitor, androgen deprivation therapy, and/or chemotherapy as part of their clinical care will be enrolled in this study. A pre-treatment 18F-FluorThanatrace (\[18F\]FTT) positron emission tomography/ computed tomography (PET/CT) scan will be done prior to the start of a new therapy regimen. PET/CT imaging will be used to evaluate PARP-1 expression in sites of prostate cancer using the investigational radiotracer \[18F\]FTT. This is an observational study in that \[18F\]FTT PET/CT will not be used to direct treatment decisions. While patients and referring physicians will not be blinded to the \[18F\]FTT PET/CT results, treatment decisions will be made by the treating physicians based upon clinical criteria. After injection of \[18F\]FTT patients will undergo a skull base to mid-thigh scan, starting at approximately 60 minutes post injection. PET/CT imaging sessions will include an injection of 12 mCi of \[18F\]FTT intravenously (approximate range for most studies is anticipated to be 8-12 mCi ). of \[18F\] FTT. Data will be collected to evaluate uptake of \[18F\]FTT in sites of prostate cancer, which will be compared with PARP-1 expression in tissue, when available. All evaluable patients may start new therapy following the \[18F\]FTT PET/CT scan. It is expected that due to patient preference and time considerations, approximately 80% will also undergo a second (optional) scan that will be performed approximately 1-21 days after new therapy has started. The second scan is obtained to evaluate whether the initiation of a PARP inhibitor and/or androgen deprivation therapy and/or chemotherapy alters \[18F\] FTT uptake.