Radiation therapy for pituitary gland cancer

Radiation therapy uses high-energy rays or particles to destroy cancer cells. It is sometimes used to treat a pituitary neuroendocrine tumour (PitNET), which is the most common type of pituitary gland cancer. You may have radiation therapy to:

• destroy cancer cells left behind after surgery (called adjuvant therapy)
• help control the symptoms of functional tumours that are making too much of a certain hormone
• treat cancer that comes back (recurs) after surgery
• destroy cancer cells in the body when surgery can’t be done

Your healthcare team will use what they know about the cancer and about your health to plan the type and amount of radiation, and when and how it is given.

During external radiation therapy, a machine directs radiation through the skin and skull to the tumour and some of the tissue around it. External radiation therapy is also called external beam radiation therapy.

Stereotactic radiosurgery (SRS) delivers precisely targeted high doses of radiation to tumours in difficult or hard-to-reach areas in fewer sessions. It creates many beams of radiation from different angles that meet at the tumour. The tumour itself receives the highest dose of radiation, and the healthy tissue around the tumour receives a lower dose from the individual beams that travel through it. This lowers the effects of radiation on healthy tissue surrounding the tumour.

Stereotactic radiosurgery is most often used for small tumours if they are far away from the optic nerve. This is because the high doses of radiation used in stereotactic radiosurgery can damage the optic nerve if they are too close.

During radiation therapy, your healthcare team protects healthy cells in the treatment area as much as possible. Side effects of radiation therapy will depend mainly on the size of the area being treated, the specific area or organs being treated, the total dose of radiation and the treatment schedule. Tell your healthcare team if you have side effects that you think are from radiation therapy. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them.

These are common side effects of radiation therapy for PitNETs:

• fatigue, feeling cold and weight changes when the pituitary gland doesn’t make enough of 1 or more hormones (called hypopituitarism)
• hair loss
• skin problems
• eye and vision problems
• nausea and vomiting
• problems with memory or thinking

Find out more about radiation therapy and side effects of radiation therapy. To make the decisions that are right for you, ask your healthcare team questions about radiation therapy.