Detecting cancer with proton therapy

Members of the multi-national research team behind the PRaVDA (Proton Radiotherapy Verification and Dosimetry Applications) project, led by the University of Lincoln (UK), are now building the instrument that will produce for the first time detailed three-dimensional images of a patient’s anatomy, using protons rather than x-rays.

To produce these Proton CT images, the world-first technology will use the same high energy particles that are used to destroy a tumour during proton therapy treatment.

Like x-rays, protons can penetrate tissue to reach deep tumours. However, compared to x-rays, protons cause less damage to healthy tissue in front of the tumour, and no damage at all to healthy tissue lying behind, which greatly reduces the side effects of radiation therapy. Led by Nigel Allinson from the University of Lincoln, the PRaVDA team aims to become the first in the world to produce clinical-quality Proton CT imagery. They are currently working near Cape Town at the South African National Cyclotron — a type of particle accelerator.

Allinson said: “Proton therapy is an improved approach for treating challenging tumours especially in the head and neck, and near critical organs. It is likely to become the preferred radiotherapy method for most childhood cancers, as the unwanted exposure to radiation of healthy tissue is much reduced and so the risk of second cancers later in life is also much reduced.”

He added that having the ability to administer a high dose in a small region is the main underlying advantage of proton therapy, however accurate planning is absolutely essential to ensure that the dose does not miss the target tumour.

PRaVDA researchers believe that Proton CT will soon be used as part of the planning process for cancer patients, as well as during and after treatment.

Proton therapy is rapidly gaining momentum as a cancer treatment.

The NHS will open two proton therapy centres in 2018 and up to another four private centres are also being planned for the UK. — ANI

Protons cause less damage to healthy tissue in front of the tumour, say scientists