The system uses several X-rays, taken at different angles, to produce detailed images. These precise details mean that we can target your treatment more effectively. The scan usually takes less than 5 minutes.
You will be asked to lie on the CT couch on special immobilisation. Depending on the site being treated you will be set up in a different position. Three temporary wire marks will be placed on your skin which will show up on the scan. The scan will only take a few minutes, during which you can breathe normally. Once the scan is completed the radiation therapist will remove the wire markers from your skin.
The entire planning procedure should take approximately 30 minutes. It is important to lie still during the planning procedure to ensure accurate measurements can be taken. The radiation therapists are there to explain the procedure and to answer any questions you may have.
Depending on your site of cancer, there are some extra things you may need to do:
- you may benefit from a Radiation Therapy technique known as deep inspiration breath-hold
- you may need a full or empty bladder
- you may need an IV contrast to show up certain areas of the body
Information for Pateints Receiving Radiotherapy to the head, mouth & neck
When radiotherapy is given to treat tumours of the head and neck area or brain tumours, it is even more important to be as still as possible. To help with this, a radiotherapy mask (sometimes called a mould, head shell or a cast) is made to be worn during the treatment. Once the mask is fitted, it is fixed to the radiotherapy treatment table. This ensures that your head and neck are held in exactly the right position for the treatment.
Wearing a mask reduces the possibility of any movement while the radiotherapy is given. The mask is only worn during the planning procedures and during the treatment itself, which usually takes about 10-15 minutes at a time each day. You will wear the same mask for planning and treatment. You will not have to wear the mask at any other time.
At St. Vincent's Private Hospital we use thermoplastic masks. These makss use a type of plastic that becomes soft and pliable (thermoplastic) when heated in warm water.
It is put on your head & shoulders so that hte plastic gently moulds to it your exactly. It feels a little like a warm flannel. The mask has many holes in it so you will be able to breath easily.
Once the mesh has moulded and becomes hard (which takes a few minutes), the CT planning scan is taken and following this the mask is removed. It is then ready to be used when you have your treatment.
Planning the radiotherapy treatment
It can take a few days up to 3 weeks to plan your radiotherapy treatment. During this time the medical physicist’s team, dosimetrists and your radiation oncologist will decide on your individualized treatment plan using a computerised treatment planning system called Monaco® HD Treatment Planning.