Before radiotherapy begins, several preparation steps ensure precise delivery of the treatment.
A mask is made to immobilize your child’s head during each treatment.
A simulation is then done to ensure the radiation is delivered accurately.
These preparations may be done on one day, or several days apart.
A light, plastic mask will be made to hold your child’s head still and ensure the x-rays are delivered accurately each day. The mould will be made by a specially trained technician while your child lies on her back.
If your child is receiving radiation to the spine or another part of the body, a special foam or plaster cast may be made of her body to deliver the radiation accurately.
You and the technician should work together to ensure the mould making is not traumatic. If your child is old enough to understand, the technician should explain and demonstrate the entire process before starting.
A water-softened pliable mesh sheet will be placed lightly over your child’s face, moulding quickly to her features. The material feels a little warm and takes only a few minutes to set. She will be able to breathe through the material, but must lie still for a few minutes as the mask hardens.
The mould will then be lifted off and used to make the clear plastic mask. Holes will be made in the mask through which radiation can travel. Another large hole will allow your child to breathe and be intubated if she is given general anaesthetic.
This process takes several hours, involving both the radiation oncologist and radiotherapist. As no high-dose radiation is used, you will usually be allowed to stay in the room to support your child, if she is not sedated.
CT scan images and measurements will be taken to calculate the treatment field. The treatment table, angle of the machine and width of the x-ray beam will be adjusted, and their precise details recorded for future set-up.
Small ink marks will be drawn either directly on your child’s skin, or to special tape placed on her face. These show the correct position for the mask, and should not be scrubbed in the bath or shower during treatment. If they fade or the tape comes off, replacement marks can be made. Try to keep the tape in place all week during treatment.
If your child is receiving spinal radiation, tiny black dots may be tattooed on her skin. A dot of India ink on the skin will be pricked with a pin to make the dot. They look like minute black freckles.
Prepare Your Child
Very young children can complete both mask making and simulation without sedation, if they are well prepared. The more time you and the medical staff spend on preparation, the faster and less stressful procedures will be.
If mask making and simulation are a positive experience for your child, she will be better prepared to attempt radiotherapy treatment without sedation or general anaesthetic.