Early analysis of images after 6 patients showed no activity of the radiotracer in this patient population.

The investigators plan to enroll 30 evaluable patients with (1) a histological diagnosis of advanced pancreatic ductal adenocarcinoma who have demonstrated at least stable disease following ≥16 weeks of treatment with platinum-based chemotherapy and (2) who have signed consent to participate in a clinical trial that contains PARP inhibitor therapy and are anticipated to receive this treatment or (3) will receive PARP inhibitor therapy as part of their clinical care.

A pre-treatment 18F-FluorThanatrace ([18F]FTT) positron emission tomography/computed tomography (PET/CT) scan will be done prior to the start of treatment with a PARP inhibitor.

PET/CT imaging will be used to evaluate PARP-1 expression in sites of pancreatic 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.

Patients will undergo approximately 60 minutes of dynamic scanning starting at the time of injection of [18F]FTT. This procedure will be followed by a skull base to mid-thigh scan, starting at approximately 60 minutes post injection. PET/CT imaging sessions will include an injection of approximately 10 mCi (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 pancreatic cancer, which will be compared with PARP-1 expression in tissue, when available.

All 30 evaluable patients are expected to start PARP inhibitor therapy following the [18F]FTT PET/CT scan. It is expected that due to patient preference and time considerations, approximately 24 patients (80%) will also undergo a second (optional) scan that will be performed approximately 3 weeks (± 1 week) after therapy has started. The second scan is obtained to evaluate whether the PARP inhibitor therapy decreases [18F]FTT uptake, which would suggest PARP blocking by the therapy.

Inclusion Criteria:

• Participants will be ≥ 18 years of age.
• Histologically proven pancreatic adenocarcinoma. .
• Deemed to have achieved stability following ≥16 weeks of platinum based therapy, in the opinion of an investigator
• Considered a candidate for PARP inhibitor therapy, with or without additional agents, either on a clinical trial or as part of clinical care.
• Participants must be informed of the investigational nature of this study and provide written informed consent in accordance with institutional and federal guidelines prior to study-specific procedures.

Exclusion Criteria:

• Females who are pregnant or breast feeding at the time of screening will not be eligible for this study; a urine pregnancy test will be performed in women of child-bearing potential at screening.
• Inability to tolerate imaging procedures in the opinion of an investigator or treating physician
• Serious or unstable medical or psychological conditions that, in the opinion of the investigator, would compromise the subject's safety or successful participation in the study.