A 15-year-old with a rare brain tumour is to undergo pioneering proton beam therapy at the UK’s first dedicated treatment centre.

Mason Kettley, from West Sussex, will receive the highly targeted therapy at the Christie NHS Foundation Trust in Manchester - home to the world's newest proton beam therapy centre.

Mason was diagnosed in October after noticing something was wrong when he wasn't gaining weight and suffering headaches.

Results from an MRI scan revealed an inoperable tumour in his brain.

  • WATCH: Mason describes reaction to diagnosis

Mason is one of the first patients to undergo proton beam therapy in the UK and the first to go public.

Until now, British patients needing the treatment had to travel to countries including the US.

  • What is proton therapy?

It is a highly targeted treatment that hits tumours much more precisely than conventional radiotherapy.

This makes it beneficial for patients with difficult-to-treat tumours in critical areas, such as in the brain or spinal cord, and for young people whose tissues are still developing.

It also helps shrink tumours and cuts the risk of side-effects.

Proton therapy is challenging to deliver. There are considerations that you need to take into account that you wouldn't normally take into account with standard x-ray treatment. But in essence, you are treating the tumour and sparing as much normal tissue as possible. As long as you can accurately deliver that treatment to the patient, to cover the tumour and perhaps a very small margin of normal tissue around it, then that's the best way to treat children." > >

Dr Ed Smith, Clinical Director of Proton Therapy, Christie

Mason will undergo proton beam therapy across six weeks.

He says the goal is to stabilise the tumour.

With a love of science, he hopes to go on to university and become a doctor.

Proton beam therapy hit the headlines in 2014 when the parents of Ashya King, who was due to undergo chemotherapy and radiotherapy at Southampton General Hospital, fled with him to Spain.

Ashya King in 2018

They were arrested in Spain but eventually were allowed to take him to Prague for proton treatment.

Ashya is currently cancer-free and back at school.