Criteria

Ages Eligible for Study: 17 years of age or older Genders Eligible for Study: Both Accepts Healthy Volunteers: No

Inclusion Criteria

Patients who meet all of the following criteria are eligible for enrollment as study participants:

1. Patients 17 years of age or older.
2. Cystic sellar, suprasellar, parasellar or intrasellar masses diagnosed by histology, cytology or neuroimaging.
3. Tumour measurements and/or tumour volume can be calculated.
4. Patients who require surgical intervention as determined by the treating neurosurgeon.
5. Being a patient managed in the Halifax Neuropituitary Program surgical clinic.
6. Willingness to undergo surgery and give informed surgical consent.
7. Willingness to provide informed consent for study participation.

Exclusion Criteria

Patients who meet any of these criteria are not eligible for enrollment as study participants:

1. Neurosurgeon's assessment that surgical procedures hold unacceptable operative risk.
2. Having a solid tumour.
3. Pregnant or breast feeding at time of surgical consent and/or surgery.
4. Hypersensitivity, allergies or contraindication to the used radiopharmaceutical agent (90yttrium colloid).