There is no consensus in the literature on the best way to treat cystic lesions of the pituitary area. Patients who are symptomatic from these tumours are rare. The cystic form of tumours present special challenges since traditional treatment modalities (surgery and/or external radiation) are often not able to completely remove or treat the cyst wall without major morbidity or even mortality.

There is no 'best practice' for the treatment of cystic tumours per se. Treatments available to patients with cystic sellar/parasellar tumours include conservative management using a 'wait and scan' approach, cyst drainage, and cyst removal via transsphenoidal and/or craniotomy approach (i.e. open surgery). Over the last 10 years we have treated approximately 8 patients with intracystic radiotherapy. All of these patients continue to be monitored clinically and radiologically and all have done well with stable regression of the cysts and no new neurological deficits. Over the past 2 years, 90yttrium colloid has been provided to CDHA through Health Canada's Special Access Program (SAP). It has only been of recent that Health Canada has requested a clinical trial to assess the benefit of intracystic radiotherapy over other available treatment options.

The experimental treatment being proposed is the stereotactic intracavitary instillation of 90yttrium colloid for treatment of cystic lesions of the pituitary (sellar) and surrounding areas (parasellar).

Surgical procedures will be performed as standard of care. The treating neurosurgeon (Dr. David B. Clarke) will determine surgical parameters based on his clinical expertise.

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).

Open label, patients assigned to treatment group