A white plastic mask is providing an innovative way of improving cancer treatment.

Patients who need radiotherapy on the brain or face and neck have to keep still during treatment to avoid rays hitting the wrong place.

To do this a mask is placed on a patient's face and secured to the trolley they are lying on.

Until now patients at the Sussex Oncology Centre at the Royal Sussex County Hospital, Brighton, have had to endure a laborious and distressing process as staff create a mask to fit their face and head.

A plaster cast mould is made of their head, which means having their face covered with cling film and wrapped in plaster of Paris bandages.

Plastic material is heated and softened and placed over the cast to form the shape of the mask.

If the end result is not exactly right, or the patient loses or gains weight as treatment progresses, then they would have to go through the same long process again.

The new mask is made of a thermoplastic material that comes in sheet form.

Hospital staff simply have to heat the plastic at 21C (70F) for about 15 minutes to make it malleable.

Then, starting at the neck, they carefully bend the plastic over the patient's face and mould it into shape.

The whole process only takes a few minutes compared with the five hours it takes the team to make the old-style mask.

If there are any changes, part of the mask can be reheated and reshaped or a new one made.

The Royal Sussex is the only hospital in England to use the new material, which comes from Denmark.

The development of the system at Brighton has been carried out by pre-treatment superintendent Marilyn Seabrook, senior mould room technician Karen Grimshaw, mechanical clinical technologist Michael Brittain and medical technical officer Robert Marlow.

The £24,500 needed to bring in the new system is being met by the fund-raising group the Sussex Cancer Fund for Treatment and Research.

At present, it is a pilot scheme and most patients are still having the old masks made. But if successful, all people will eventually have the new masks.

Mrs Grimshaw said: "Patients benefit because they only have to come in once to have the mask made whereas before they were having to come in twice.

"Once to have the cast made and again to check the mask fitted.

"It is also an easier, quicker and less distressing process for patients who are already in a vulnerable frame of mind.

"As far as we are concerned it means we do not have to lift heavy plaster casts or work in the dusty atmosphere caused by making the plaster of Paris.

"It is a simple device but it is going to help a large number of patients."