One-Stop Pituitary Clinic - What To Expect

As endocrinologists, we are experienced in diagnosing abnormal production of pituitary hormones. We provide clinical evaluations and closely monitor patients throughout diagnosis and treatment. Sometimes the diagnosis of pituitary hormone overproduction or insufficiency requires more advanced neuroendocrine testing. This is done in our Clinical Investigation Unit (CIU) at St. Joseph's Hospital.

Overproduction of pituitary hormones can result in:

• Acromegaly: too much growth hormone
• Cushing’s disease: too much ACTH and cortisol
• Prolactinoma: too much prolactin
• TSH adenoma: too much production of thyroid hormone

Other pituitary tumors may be hormonally inactive, and sometimes they cause pituitary hormone insufficiency. This may also be caused by other diseases in the pituitary area, such as apoplexy or craniopharyngeomas.

As endocrinologists we are experienced in the use of drugs to reduce the hormone overproduction and in the replacement of hormones that are insufficiently produced.

Neuroendocrine testing 

In the Clinical Investigation Unit (CIU), we perform dynamic tests that will help to diagnose pituitary hormone overproduction or insufficiency. The nature of the tests varies in relation to the specific hormone that is being tested.For some tests, fasting is required of food and/or fluids. For other tests you may need to stop some medications. It's important to check with the nurse in the CIU regarding what you need to do before you come for your appointment. The nurse will also let you know approximately how long the test will take.

Upon arrival in the CIU, we will take your blood pressure and heart rate, and insert an intravenous canula, which is used for taking blood samples and to administer drugs as required for the specific test.

The CIU is located in Zone B of  St. Joseph’s Hospital, room B5-502.  Enter the hospital via Grosvenor Entrance 2 on Grosvenor Street  and take the first bank of elevators to level 5. Turn to the right to register at the the Diabetes & Endocrine Clinics.

ENT surgeons collaborate with the neurosurgeon to remove the tumor by using your nose as a pathway to access the brain. ENT surgeons with special expertise in endoscopic (minimal access) nasal surgery are trained to assist neurosurgeons in performing this delicate surgery. After surgery sometimes the nose has packing or crusting in it that must be cleaned up and the ENT surgeon will do this work as well. If there is a brain fluid leak after surgery, the ENT surgeon will fix this issue.

What happens in the ENT clinic

The ENT surgeon will examine your nose to assess if it is suitable for a trans-nasal surgery. This is done via nasal endoscopy, a standard and non-painful exam that allows the surgeon to look at the inside of your nose, near where the tumor is.  After the endoscopy is completed the ENT surgeon will go over the nasal portion of the surgery with you and answer any questions you may have.

Number of ENT clinic visits required

You will make one pre-operative visit as part of the One-Stop Pituitary clinic, and then typically 1-2 visits after to ensure your nose is healing well.

The role of the neuro-ophthalmologist

Neuro-ophthalmologists are doctors specializing in the neurology of the visual system. This includes the eyes, of course, but also the nerves behind the eyes (the optic nerves), which carry visual information to the brain so you can “see”.

The pituitary gland sits directly beneath the optic chiasm, the place where the two optic nerves cross on their way to the brain. Tumors that arise from the pituitary gland commonly grow upwards, squeezing the optic chiasm and disrupting vision. When a pituitary tumor compromises vision, it affects peripheral (side) vision first, and the changes can be so subtle that patients may not realize they are losing vision. 

Right before your visit with the neuro-ophthalmologist, you will be sent for a “visual field test” at the Ivey Eye Institute at St. Joseph’s Hospital. This is an important non-invasive test of your peripheral vision that takes about 15 minutes to complete.  A visual field technician will explain the test to you and help you through it. You will be asked to stare at a target while flashes of light appear in your peripheral vision.  You must press a button when you see the flash appear.  Each eye is tested separately. 

What to expect at the neuro-ophthalmology clinic 

Following the visual field test, you will go to the neuro-ophthalmology clinic, either at the Ivey Eye Institute (Pod 5) or at London Health Sciences Centre's University Hospital (7th floor). The neuro-ophthalmologist or his resident will take a detailed history from you and will review previous records and tests. Then, he will perform a very detailed physical examination of your eyes. Your eyes may be dilated with drops, so please bring a driver with you as your vision may be blurry for up to six hours afterwards.  

Not including the visual field test, your appointment will take one to two hours, so be prepared.  Please be sure to bring an up-to-date list of all your medications and your glasses.

Neuroradiology involves the diagnosis and treatment of brain, spinal cord, head and neck, and vascular lesions using x-rays, magnetic fields, radio waves, and ultrasound.

Imaging modalities used to diagnose pituitary tumors include:

CT scan

• Usually done with intravenous contrast injection for assessing the pituitary gland.
• May be done without contrast injection for surgical planning.
• The patient lies on the bed in the gantry of the scanner.
• The x-ray tube is contained in the circular part of the scanner

MRI scan

• Can be done with or without contrast, or both with and without intravenous contrast
• The contrast agent is different than that for CT
• A head coil is placed around the head to obtain the images
• The machine makes banging, tapping, drum beat sounds

For more information on these imaging modalities, visit the website of St. Joseph’s Medical Imaging Centre.

Decisions regarding surgical removal of pituitary and skull base tumors are done collectively, with input from all the team members of London's interdisciplinary Pituitary Group. Once surgery is decided upon, patients are admitted to the neurosurgical service at London Health Sciences Centre's University Hospital for the surgery. Surgical cases are triaged according to urgency with wait times ranging from weeks to months. The time needed to perform the surgical procedure are patient specific and the typical hospital stay is 3-5 days following surgery.

How surgery is done

Dr. Neil Duggal directs the neurosurgical team.  The neurosurgical team is responsible for removal of the tumor and provides help in the repair of spontaneous cerebrospinal fluid (CSF) leaks. The objective of the surgical teams is always to optimize tumor removal while maintaining patient safety.

The neurosurgical and ear, nose and throat (ENT) surgeons work together, adopting minimally invasive endoscopic, endonasal (through the nose) techniques to eliminate incisions, optimize visualization and improve patient outcomes.

What happens after surgery

After surgery, blood work will be monitored by endocrinologists and family physicians.  The first follow-up with the neurosurgical team is 6 weeks after surgery.  A second follow up meeting at 6 months will be organized to discuss post-operative imaging and endocrine status. 

While radiation therapy is typically used to treat malignant brain tumors or other cancers in the body, radiation therapy is also effective in treating benign brain tumors like pituitary adenomas. Radiation treatments are usually given following surgery for pituitary tumors if the surgeon cannot completely remove the tumor.   Sometimes radiation treatments are used instead of surgery if the tumor cannot be removed safely.  

Please note: Radiation therapy is provided at the London Regional Cancer Program of London Health Sciences Centre.  

Planning and preparation

The radiation oncologist is the physician who assesses and prescribes radiation treatments for patients and works with a radiation team including dosimetrists, physicists, radiation therapists and nurses to ensure radiation treatments are given accurately and safely. The process of radiation therapy involves an initial consultation with the radiation oncologist and once a decision to treat is made treatment planning is commenced. As part of the planning process a custom plastic mask is made and this is worn for treatments in order to ensure the patients head is in the proper position and is held still for the treatments.   

Following the construction of the mask a CT scan obtained with the patient in the mask is obtained and this scan allows the radiation oncologist to specify the location of the tumor to be treated as well as normal tissues to be avoided. The process of making the mask and obtaining the scan usually takes about 45 minutes.  An MRI scan will often also be performed during the same visit.  After the planning visit, the radiation team takes the information obtained and designs a customized radiation plan with the goal of selectively treating the pituitary tumor while avoiding uninvolved organs such as the eyes, optic nerves and brain.

Radiation treatments

Most patients can expect to start radiation treatments within 1-2 weeks of their planning visit. Patients are usually treated on a daily basis, Monday to Friday, 25-30 treatments over 5-6 weeks. Treatments with radiation usually take 15-20 minutes per day and the most common 
side effect during treatment is mild tiredness. Less often there may be some hair thinning or mild skin irritation. These side effects will usually 
go away over a few weeks (tiredness, skin irritation) or months (hair regrowth). 

Follow-up care

Regular follow-up by your radiation oncologist, endocrinologist and neuro-ophthalmologist after treatment is important to monitor the success and potential long term side effects of treatment. Severe long term side effects of radiation such as vision loss, stroke, impaired thinking or a second brain tumor are very rare but can occur months to years after radiation.  Monitoring of pituitary function after radiation is necessary as adjustment in pituitary hormone replacement drugs is often necessary.  Scans to monitor the tumor are also performed on a regular basis (usually yearly).  Pituitary tumors rarely shrink after radiation and successful radiation treatment is indicated by the absence of growth of the tumor on monitoring scans.

For more information on radiation therapy, visit the London Regional Cancer Program website.