Proton Therapy Congress 2016

Building a succesful proton therapy centre 

Prof James Metz - University of Pennsylvania, Philadelphia, USA

Our centre has been in operation now for almost seven years so we’ve had a lot of learning throughout that time period of seven years. We learned a lot and we did well, some things we had to work on and change what we did so we want to make sure that other centres learn from where we started and what has been successful and what hasn’t been successful.

What was the state of proton therapy like when your centre opened?

Our journey actually started much earlier - in 1999 we tried to start building a proton centre. We actually didn’t sign a contract until 2006 and 2010 is when we treated our first patient. So there has been a tremendous change in treatment from when we started getting involved with this field in 1999 up to 2010 when we started treating patients. Really computers and imaging has really driven the field of proton therapy for the last decade as we’ve seen improvements in both of those areas we’ve been able to better image tumours and we’ve been able to place the dose better than we could before. So you’ve seen developments such as pencil beam scanning where we can treat spot by spot or cone beam CT or CT imaging in the proton treatment room that really allows us to treat additional treatment sites that we really couldn’t before.

How are treatment sites developing?

Our centre at the University of Pennsylvania has actually treated a wide variety of sites with proton beam therapy. So our main sites are actually lung cancer, GI cancers, paediatric tumours being an important one. But many of these patients are patients that are receiving combined chemotherapy and radiation because we’re seeing reduced toxicity when we combine the two agents together as opposed to previously when we combined it with conventional radiation it was just too toxic for many patients. So we’re seeing markedly reduced toxicity in that setting.

Combination therapy is alongside immunotherapy and proton therapy as one of the next big steps.

We’re extremely interested in exploring immunotherapy. Much of the data right now is in the conventional treatment realm with stereotactic body radiation therapy, or SBRT, but we’re looking to expand that to proton therapy. We’ll be doing a lot of work in our research room, actually, to define what is the best way to deliver this, and then bring that into the treatment modality and new clinical trials with protons.

What are your thoughts on the proton vs photon debate?

Protons are a tool in the toolbox, they’re not going to be perfect for everything, quite frankly. But I think they’re going to be good for a number of treatments that are going to be widely accepted a few years from now. I’m already seeing the difference from where we were five years ago to now and I agree, five years from now we’ll see much of a difference from what’s accepted. But that doesn’t mean conventional radiation is going away. I look at protons as really a tool in the toolbox for the radiation oncologist, it’s an important tool but not for every single thing we treat either.

What is your take-home message?

Learn from others that have gone before you. So we visited every centre that was in operation at that time and learned what they would do differently, what they would think about the next generation. So we learned a lot from the previous centres that were out there, so spend time with them. Understand that training is critical, these are complicated centres, very different from a conventional linear accelerator and you need specialised training in physics, in dosimetry, in therapy and in the physicians in making sure to put those investments in that area and really starting years ahead, almost before you open the centre to get those people trained up to the appropriate level. And working with clinical protocols that are really already in place and have been proven, particularly when you start a centre so that way your team can get experience with some simpler treatments and then build up your repertoire of various treatments.