A Study of Hypoxia Imaging in Advanced Pancreatic Cancer Patients Being Treated With Gemcitabine and TH-302 or TH-302 Placebo

Inclusion Criteria: * Have consented to participating on the first-line Gemcitabine + TH-302/placebo (study number EMR200592-001) study * Age 18 years or older * Cytologic/histologic diagnosis of pancreatic adenocarcinoma * Advanced stage pancreatic cancer: locally advanced or metastatic. * No prior chemotherapy for advanced/metastatic disease. Adjuvant chemotherapy allowed if completed \> 6mths from study entry. Prior radio-sensitizing doses of 5-FU or gemcitabine also allowed. * ECOG performance status 1 or less * Adequate end organ and marrow function * Measureable or non-measureable disease by RECIST 1.1 * Female patients of child-bearing potential must have a negative serum pregnancy test (BhCG) and must agree to abstinence or use adequate contraception for the duration of the study * Disease-free period of more than 5 years from prior malignancies other than pancreas (except curatively treated basal cell carcinoma, squamous cell carcinoma of the skin, or carcinoma in situ of the cervix and ductal carcinoma in situ (DCIS) breast disease). * Ability to provide written informed consent * Must be able to lie flat comfortably for 30 to 60 min to complete imaging study Exclusion Criteria: * Inability to lie supine for 30 to 60 minutes * Concurrent second primary * Life expectancy of less than 12 weeks * On treatment with disulfiram (antabuse) due to \[18F\]FAZA injection containing up to 10% (v/v) ethanol in PBS (phosphate-buffered saline)