Proton Therapy Congress 2016
Photon therapy in a proton age
Dr Andrew Gaya - Guy’s and St Thomas’ Hospital, London, UK
The whole field of proton therapy for me is of great interest. There are very significant physical benefits of protons over photons, whether that translates into a real benefit to patients is a very difficult question that we have to ask ourselves. No doubt over the coming years we’ll have that data in a little more detail, but I think we have to take a lesson, because I see huge parallels between what we’re going through now in terms of proton therapy with what we went through ten years ago with stereotactic radiotherapy and CyberKnife where we had a whole host of early data, usually single institution retrospective studies; data that was at times of fairly dubious quality. We had manufacturers putting undue pressure on the media, pressure within the political system as well for the introduction of new technology before we actually had really good quality randomised data. Actually, if you play devil’s advocate, even today ten years later, for stereotactic radiotherapy, if you look for prospective randomised trials comparing it with conventional treatment there’s actually very little data. The best data we have is in lung cancer but if you go out to some of the other tumour types, liver metastases, pancreas cancer, the data quality really is very poor. So we as a group need to learn from that and design good quality studies from the outset and really get our data collection quality right up there as well so that we are not in the same position in ten years’ time with protons as we are now with SBRT.
What do you think clinicians should do differently, now that proton therapy is an emerging field?
I think we have to collaborate much more than has happened in the past. We are now seeing that with stereotactic radiotherapy within the UK in that we have NHS England commissioning through evaluation scheme which is enabling us to collect data prospectively. I hope in due course we may have a similar scheme for proton therapy once the two NHS units go live. The other helpful thing is that the cost of proton therapy is coming down. The cost effectiveness argument, which is a very powerful one within a restricted healthcare system such as the NHS where we have to show value for money, it’s clearly very, very difficult when you have a treatment that is at least twice as expensive as the current gold standard. There’s a cost effective argument on one side, but the data quality argument on the other side as well, and I think we have to learn those lessons from the past and really do our very best to ensure that we have robust data collection from day one, prospectively analysed.
The UK can take a lead in this because we are very good at collaboration, we are very good at working together as a group and we have the infrastructure in place to be able to do that. We have the CORE clinical trial about to start, looking at stereotactic radiotherapy for oligometastatic disease to try and get that phase III randomised data to show once and for all is there or is there not a benefit. We have to learn those lessons for proton therapy, even more so when you have a treatment that’s two or three times more expensive even than stereotactic radiotherapy, the data quality argument and the cost effectiveness argument becomes ever more important.
Where would you like to see proton therapy in 5 years?
There are physical benefits to treating patients with protons, whether those will actually turn into improved outcomes is the unknown, so that really for me is the big question. Are we going to see, as a result of those physical benefits, us able to dose-escalate patients and improve control outcomes for tumours but also are going to see a reduced toxicity as a result of those physical benefits as well. I’d like to think that we will, I’d like to think that we’re always taking a step forward but, as I say, at the moment we simply don’t know the answers to those questions. We have to know the answers to those questions to be able to offer value for money and to be able to offer cost effectiveness to patients.
There is maybe a little bit of a conflict as well in that the drive towards protons can be driven by patients, it can be driven by the media and I think we are a group of clinicians have to respect that. We want to innovate but we have to innovate with robust data. We have to innovate in a responsible way and collect our data in a responsible way and not be driven by media, not necessarily to be driven by these very emotive arguments, the obvious case being Ashya King, for example. I can’t stress enough the importance that we have that robust data collection from day one to prove whether or not this technology is worth the extra cost, the extra expense.
