The purpose of this study is to test if PET scans using 89Zr-DFO-cRGDY-PEG-Cy5-C' dot particles, can be used to take pictures of brain tumors. The investigators want to understand how the particles are distributed and removed from the body, which may help others be treated in the future. This will be the first time that 89Zr-DFO-cRGDY-PEG-Cy5-C' dot particles are being used in people. The amount of particles given in this study is very small compared to the amount that was used in mice animal studies.

Inclusion Criteria:

• 18 years of age or older
• Histologically confirmed diagnosis of malignant primary brain tumor clinical and radiographic findings consistent with a pituitary adenoma, or known metastatic cancer with brain lesion presumed to be metastatic.
• Normal baseline cardiac function based upon pre-operative evaluation at the physcian's discretion
• All patients of childbearing age must use an acceptable form of birth control
• Women who are pre-menopausal must have a negative serum pregnancy test

Exclusion Criteria:

• Known pregnancy or breast-feeding Medical illness unrelated to the tumor which in the opinion of the attending physician and principal investigator will preclude administration of the tracer

  °This includes patients with uncontrolled infection, chronic renal insufficiency, myocardial infarction within the past 6 months, unstable angina, cardiac arrhythmias other than chronic atrial fibrillation and chronic active or persistent hepatitis, or New York Heart Association Classification III or IV heart disease

• More than one metastatic cancer active in the last 5 years

• Active metastatic cancer in addition to malignant primary brain tumor

• Weight greater than the 400-lb weight limit of the PET scanner

• Unmanageable claustrophobia

• Inability to lie in the scanner for 30 minutes

Two expert PET scan readers, who are board-certified in Nuclear Medicine, will be designated to read and evaluate PET-CT scans. Volumetric region-of-interest analysis and extraction of the mean and maximum standard uptake values (SUVs) will be provided. Both readers will initially be blinded to the patient's clinical information for scan interpretation. A second interpretation will then be performed after both readers are provided with clinical information about the primary tumor site.