The primary purpose of this study is to examine the safety and potential effectiveness of a drug molecule called 64Cu-SARTATE as a potential new way to detect neuroendocrine cancers.

Inclusion Criteria:

1. Signed informed consent
2. Age greater than or equal to 18 years
3. Life expectancy greater than or equal to 8 weeks
4. Low and Intermediate Grade (Ki-67 index <20%) neuroendocrine tumors (NET)
5. At least one site of active somatostatin receptor positive malignancy, as demonstrated on the pre-study 68Ga-DOTATATE PET/CT scan performed as part of routine clinical care
6. Subjects with an estimated glomerular filtration rate (eGFR) greater than 60ml/min as measured using the MDRD formula (Modification of Diet in Renal Disease).
7. Eastern Cooperative Oncology Group (ECOG) performance score of 0-2

Exclusion Criteria:

1. Pregnant or breastfeeding females
2. Known sensitivity or allergy to somatostatin analogues
3. Subjects who have received interventional treatment for their NET in the interval between 68Ga-DOTATATE PET/CT & 64Cu-SARTATE PET/CT scan
4. Treatment with long acting somatostatin analogues within 28 days prior to the administration of Investigational Product
5. Treatment with short acting somatostatin analogues within 24hrs prior to the administration of Investigational Product
6. QTc interval greater than 0.44seconds as measured by screening ECG
7. Any serious medical condition which the investigator feels may interfere with the procedures or evaluations of the study
8. Patients unwilling or unable to comply with protocol or with a history of non-compliance or inability to grant informed consent