Pituitary Tumor: Radiation Therapy
Radiation uses high-energy beams of X-rays or particles to kill cancer cells. It's often used to treat pituitary tumors that come back after surgery. If you're not healthy enough for surgery, radiation may be used to shrink a tumor that's causing problems. It might also be used to treat pituitary tumors that are causing problems or that aren't getting better with medicine.
If a tumor is very large, surgery may be done first to take out as much of it as is safely possible. Then the rest of the tumor will be treated with radiation.
Radiation works very slowly on pituitary tumors. It can take years to control a tumor's growth and hormone production.
How is radiation therapy given?
Before radiation starts, imaging scans are taken. These are used to clearly outline the size and shape of the tumor. The radiation beams are controlled and formed to fit this shape and focus on the tumor. This helps limit damage to nearby healthy tissue.
Radiation for pituitary tumors can be given in different ways. Conventional radiation comes from a machine outside the body. The machine directs the beams at the tumor. Treatment is may be given 5 times a week for several weeks.
Other types of radiation that may be used include:
Stereotactic radiation. This form of radiation precisely targets the tumor. It directs beams at the tumor from different angles. One high dose of radiation can be given. Only 1 treatment may be needed, but it can be repeated if needed. It's very precise and radiates the tumor and not the entire brain or the healthy part of the pituitary. This kind of radiation may prevent some of the side effects of standard radiation, such as memory changes. But it can’t be used if the tumor is near important nerves, such as the optic nerve.
Proton beam radiation. This type of radiation therapy uses a different type of particle (or energy) beam. It can focus right on the pituitary tumor. This helps limit radiation to nearby healthy tissues. Proton radiation is only done in certain medical centers because special equipment must be used.
It's common to have a mold, mask, or frame made before radiation starts. This will hold you in the exact same position for each radiation treatment and help keep you from moving.
Side effects of radiation for pituitary tumors
Talk to your doctor about what you might feel like during and after radiation therapy. Side effects may get worse as treatment goes on, but most of them can be treated.
Side effects often get better or go away over time after treatment ends.
The side effects of radiation therapy include:
Skin in the treated area that is irritated, dry, red, and blistered like a sunburn
Hair loss on the part of your head that the radiation passes through to reach the tumor. Sometimes the hair doesn't grow back the same.
Feeling tired or weak
Nausea and vomiting
Swelling in the brain that causes headaches, confusion, seizures, and speech problems
Damage to the healthy part of the pituitary gland that makes it stop working
Talk to your doctor about what side effects you can expect. Also talk about what can be done to prevent or ease them. Ask your doctor what symptoms to watch out for. Know when you should call your healthcare team and how to get help after office hours and on weekends and holidays.
Some long-term side effects of radiation may not show up for many years after you finish treatment. These depend on the dose of the radiation and the area that's treated. These also depend on how many times you have treatment. Ask your doctor what you may expect.