Pituitary Innovation and Teaching

Other types of treatment

Radiation therapy

Radiation therapy uses high-energy X-rays to control the growth of tumours. Radiation therapy can either be used after surgery or in cases where surgery is not an option. Radiation can also be very useful if the whole tumour cannot be removed during surgery and continues to grow, or if a tumour recurs after surgery.

There are a few ways to get radiation therapy. Your doctor will discuss which option is best for you:

  1. Fractionated radiation
  2. Stereotactic radiosurgery - Single dose radiation therapy

Fractionated radiation

In fractionated radiation therapy, patients get a small amount of radiation five times a week for four to six weeks. Because a small fraction of the total dose is given each weekday, it is called “fractionated”.  Each treatment may last for 15 to 20 minutes per day. The radiation can be given in a variety of ways. In intensity modulated radiation therapy, the radiation is given precisely to an area slightly bigger than the tumour. This makes sure that the whole tumour gets radiation. The treatment is carefully planned using MRI images of the tumour and other methods. The radiation oncology doctor will decide on the length of the treatment and the radiation therapist works the machine that delivers the treatment.

Stereotactic radiosurgery: Single dose radiation

In radiosurgery, you get all of the radiation you need in a single day. It is given in a very focused form. The most common way of having radiosurgery is with a tool called a “gamma-knife”. The gamma-knife focuses more than 200 tiny beams of radiation onto the tumour with the aid of a stereotactic frame which is like a box fixed to the patient with four little screws placed with local anaesthetic.

Since the gamma knife can target very tiny spaces, the tumours come under control faster than the fractionated way and there may be less radiation to brain tissue near the tumour. But, the highly focused beams from the gamma-knife could mean that tiny areas around the tumour could also be harmed by the radiation, so it can only be used if it is safe to do so, based on the nearby structures. Gamma-knife radiosurgery is usually a one-time therapy completed in a single day although new techniques may allow a fractionated approach over a few days.

Side effects of radiation

All forms of radiation can damage normal pituitary and brain cells, which may lead to a loss of hormones over time. In rare cases, this damage may lead to memory loss or visual loss over several years. Radiation has a small risk of causing the growth of new tumours or cancers years after treatment.

 

Page last updated: November 22, 2016