Proton beam therapy and standard radiotherapy – image description

The illustration shows the differences between standard radiotherapy and proton beam therapy. It is split into two halves.

On the left is a side view of a head. Inside the head the brain is shown. There is a tumour inside the brain. Outside of the head, a beam of radiotherapy is shown coming from the tip of a radiotherapy machine. The beam is directed at the tumour in the brain. The beam is shown passing through the tumour and out the other side of the brain.

The right side of the illustration shows the same side view of a head, including the brain and a tumour inside the brain. Outside of the head, a beam of proton therapy is shown coming from the tip of a proton beam therapy machine. The beam is directed at the tumour in the brain. The beam stops as it reaches the tumour and does not pass through it or out the other side of the brain.