Ziv-Aflibercept in Treating and Computed Tomography Perfusion Imaging in Predicting Response in Patients With Pancreatic Neuroendocrine Tumors That Are Metastatic or Cannot Be Removed by Surgery

Inclusion Criteria: * Patients must have histologically or cytologically confirmed low or intermediate grade pancreatic NET; patients with neuroendocrine tumors associated with multiple endocrine neoplasia type 1 (MEN1) syndrome will be eligible * Patients must have unresectable or metastatic disease * Patients must have at least one measurable site of disease according to RECIST 1.1 that has not been previously irradiated * Patients must have at least one lesion suitable for perfusion CT; the lesion should be greater than or equal to 3 cm in size in the cranial caudal direction * Patient must have no contraindication for CT with iodinated contrast * Patients who are on a somatostatin analogue for control of hormonal syndromes must be on a stable dose (no change in mg dose of long acting octreotide or lanreotide, changes in dosing interval of +/- 1 week is allowed) for 2 months prior to date of study entry * Women of child-bearing potential must have a negative serum pregnancy test within 7 days prior to date of study entry; women who have had menses within the past 2 years, who have not had a hysterectomy, bilateral tubal ligation, or bilateral oophorectomy are considered to be of child-bearing potential; patients with elevated human chorionic gonadotropin (hCG) at baseline that is judged to be related to the tumor are eligible if hCG levels do not show the expected doubling when repeated 5-7 days later, or pregnancy has been ruled out by vaginal ultrasound * Any number of …