NCRI 2015

New proton facilities to open in the UK and other European countries

Prof Uwe Oelfke - The Institute of Cancer Research, London, UK

I’m focussing on the driving force of modern radiation oncology, of the technology, and this is the dose delivery technology. For instance, proton therapy is something which we will have new in the next five years within the UK and the second major player I envision is MRI guided radiation therapy where you integrate an MRI scanner directly with the dose delivery system.

Are there already sites in the UK doing proton therapy?

There is a very specific place in the UK, in Clatterbridge, who are treating uveal melanoma, inner ocular tumours, with protons of very low energy. This was actually the first clinical facility or clinic based facility in the world which has done this since 1989.

Are there plans for more sites?

Now that the NHS has decided to fund two facilities with a £250 million budget there will be new proton facilities at the Christie in Manchester and UCLH in London. Then there will be a privately funded facility in Oxford. Furthermore, it was recently announced that there are three single room facilities in smaller hospitals also put up by private initiative.

Why is this technology important?

This technology is important for certain, very specific, tumours which only very few have been identified. One of the major tumour site groups is paediatrics because proton therapy will reduce the integral dose delivered to a patient when a tumour is treated by a factor of two or three. Specifically for young patients that is very important for the induction of secondary cancers, in order to reduce this risk.

Is that because it’s more accurate?

This is the physics: if protons are shot into your body you can control the energy of the protons and the energy determines how far these protons penetrate into tissue. Because there is no dose behind the dose fall-off there’s a characteristic depth that is called the Bragg peak that means there is low dose at the entrance and where the particles stop there is quite a bit of dose. This peak, if you tailor it directly into the tumour then there is no exit dose and therefore there is less integral dose when you compare it with photons.

So we will be seeing these sites in the next five years?

The Christie in Manchester is planning to treat in 2018 and UCLH one year later.

How does access to proton therapy per capita compare to other countries in Europe or in the USA?

At the moment it is very similar, it would cover in the order of 1% of the radiotherapy patients treated in the UK. So it is estimated both facilities will treat about 1,500 patients per year in their full operational status. With respect to Europe it’s quite diverse at the moment. In Germany there is a heavy ion facility running and two proton facilities, or even three now, they’re really developing. But this is one of the countries where you have most of the hadron therapy. In the Netherlands there are four initiatives which are planning to have new facilities but they are in the planning stage. There’s also something going on in Sweden, a facility will come soon. Overall we are in the right direction to figure out what is the most clinically appropriate treatment site for these very sophisticated radiation therapy technologies.

What about the second type of therapy that you mentioned?

The magnetic MRI guided radiation therapy? Yes, this is something completely new because what we need to know, and that is also true for protons and, unfortunately, that is not that much developed there either, that we have to see what we want to treat at the time of the treatment. At the moment we have X-ray based technology at all linear accelerators and for many clinical indications we just see hazy electron clouds. But with an integrated MRI scanner we can see extremely good soft tissue contrast; we can do imaging all the time, that means there is no extra radiation burden for the patient. So we can determine the motion, breathing induced organ motion, for instance, and we can adapt in real time our treatment to the variations of their anatomy. This is really new and will be a step change in the practice of radiation oncology in the future.

Is this mode of therapy more effective at treating the cancer or is it more about minimising side effects?

It’s always in radiation therapy, as in radiation oncology, we want to open the therapeutic windows. So if you are reducing side effects then that gives you the opportunity to dose escalate and to improve tumour control. This balance is this therapeutic window will open and to what extent and for what clinical indication it is best to be used has to be figured out by clinical studies in the clinical system.

Is this very expensive?

Yes, the initial investment in hardware for protons is expensive. For the MRI guided radiation therapy we are doing this with the so-called MR Linac in the UK which is introduced through a consortium of seven international partners. So we had to pay a nominal price but just for this specific arrangement to translate this into the clinic and demonstrate its clinical usefulness. So the final price of this technology depends always on how broadly they can be disseminated. At the moment we are among the first seven sites for the MR Linac worldwide and these are unique systems. But I can envision in the order of 5-10 years that, at least for the MR Linac technology, it can be very compatible in price to a high end system or maybe in a factor of two or so more price. So this depends on how valuable we can demonstrate this technology is.

Does this require advanced software infrastructure?

In order to exploit these investments in the hardware delivery or the dose delivery systems it is absolutely necessary that we have state of the art software components which interlink, for instance treatment planning software with dose delivery, in order that we can take images while the patient is treated, use this information in real time to re-optimise our treatment plan and then deliver this re-optimised treatment planned with the hardware system. So this feedback loop has to be fast and smooth and there one needs excellent software modules.

Do you think it’s important for these different clinics to work together and share information?

In my view it’s very important that these highly advanced radiation therapy technology centres work very closely together, share a common infrastructure, data exchange, design clinical trials under the appropriate leadership, depending on what clinical site it is and which hospital is the leading facility in the UK in order to co-ordinate these trials best.