Inclusion Criteria:

1. NET patients who are potential candidates for I-131 MIBG therapy, and are having
whole body I-123 MIBG scintigraphy as standard of care.

2. Male or female patients ≥ 18 years of age.

3. Written informed consent from patients obtained in accordance to local guidelines.

4. History and physical exam indicating low likelihood, < 10 %, of any significant
cardiac disease.

5. Echocardiogram within normal limits, including absence of valvular disease and normal
LVEF.

6. Serum BNP within normal limits. -

Exclusion Criteria:

1. Patients on drugs which interfere with MIBG uptake - tricyclic antidepressants,
phenylpropanolamine, pseudephredine, phenylephrine, sympathomimetics, amphetamines,
reserpine, thorazine and thiothixines, calcium channel blockers, cocaine, and
long-acting beta blockers.

2. >10% likelihood of any significant heart disease, including myocardial ischemia,
cardiomyopathies, uncontrolled hypertension, congestive heart failure and valvular
heart disease, e.g. see "Likelihood of Assessment of Coronary Artery Disease" below.

3. History of uncontrolled diabetes mellitus

4. Signs/symptoms of neurological diseases (e.g., Parkinsonian syndromes) or other
disease known to affect the sympathetic nervous system.

5. Female patients who are pregnant or nursing (lactating), or adults of reproductive
potential who are not using effective birth control methods. If there is any question
of pregnancy, a serum bHCg will be collected.