Joint CERN-EPFL doctoral research leads to design of a cutting edge machine for cancer treatment

In 2017, Enrico Felcini began his PhD in Applied Superconductivity under the supervision of Bertrand Dutoit, the head of EPFL’s Applied Superconductivity Group. His work was on a revolutionary hadron therapy gantry concept invented by Luca Bottura, who leads CERN’s magnet group. Three years later, he is the proud co-creator of a new gantry design, based on superconducting magnets, that has the potential to change the future of how we treat cancer.

Hadron therapy is of great interest to the medical community as a pioneering radiation therapy that makes use of charged particles to deliver a highly localized dose to a tumor. Unlike traditional radiotherapy, because it minimizes radiation to any neighboring tissue, it may cause fewer side effects and avoid the generation of secondary tumors.

However, because a hadron is made up of charged particles, a magnetic field is needed to ensure that it goes to exactly the right place in the patient. This requires a complex assembly of magnets in giant machines. It also needs to rotate around the patient with 0.5 mm (5 human hairs!) of precision, making it an incredibly complex piece of engineering. Currently, there are only two facilities in the world, at Heidelberg in Germany where the machine is around 13 meters tall, 25 meters in length and weighing more than 600 tons, and Chiba in Japan, where it is 11 meters tall, 13 meters in length and 250 tons in weight, because it is superconductive.

Enter GaToroid, which, as Felcini says, aims not just to reduce the size of hadron therapy machines but also their complexity, “using toroidal superconducting magnets, the idea of GaToroid is to have a machine that looks like an MRI, so instead of a gigantic rotating magnetic arm that moves around the patient, we have something circular that is in a steady state with the patient inside. This has enabled us to make the machine much smaller. However, unlike an MRI, the patient is not immersed in the magnetic field, but it is confined by the coils around them.” The idea is that this technology will make hadron therapy far more accessible as it won’t require machines the size of a four-story building.

Reflecting on his PhD research, Felcini feels it has been an honor to work on such a visionary project, “My CERN mentor, Luca Bottura is the ‘yoda-master’ of magnets and it has been amazing to work with him. I’m really proud of my contribution to GaToroid requiring the integration of several aspects of physics and engineering, such as superconductivity, beam optics, mechanics, cryogenics, vacuum, and qualification for therapy. I specifically focused on the design of the superconducting coils and integrating magnet engineering with beam dynamics through particle tracking. With all of these different aspects coming together I had an amazing chance to not focus on a single thing but the opportunity to think very broadly.”

Dr Bertrand Dutoit is looking forward to following Felcini’s career and future achievements and extolled the virtue of working in a region with such top-class research facilities, “having CERN at such close proximity is a fantastic collaboration opportunity for EPFL and Enrico had access to top scientists as well as the technical workshop team where he was able to start building the system he designed and calculated. Enrico was challenged by many different aspects of the GaToroid project, each dictating his constraints but still managed a great PhD, becoming a highly attractive scientist for research institutes and companies in the cancer treatment business.”

Work is currently underway to construct the first demonstration model, scaled down by a factor of 3 with the aim of taking the next step and building a full-scale machine in the next decade.

This article was first published on 23 October by EPFL.