Summary

Professor McNulty and colleagues have taken particle detectors developed at CERN and redeployed them in Irish hospitals as imaging devices and dosimeters (devices which measure uptake of radiation among cancer patients). Their detectors are 100 million times faster and have better image quality than current technologies, and they have the potential to improve cancer diagnosis and treatment and lead to better patient outcomes. The research also fostered new collaborations and trained students in the use of this technology. Reports to the Oireachtas have contributed to the case for Irish membership of CERN, since which the country has formally applied for membership.

Research description

At CERN’s Large Hadron Collider (LHC), the world's largest particle collider, scientists accelerate beams of protons close to the speed of light, and smash them together to uncover fundamental truths about our universe. The analysis of the collisions requires incredibly powerful three-dimensional cameras (detectors) capable of imaging elementary particles.

Ireland is home to around 30 much smaller colliders, all of which are situated in hospitals, where they’re used for radiotherapy to treat cancer. In 2017, Professor McNulty and his team invited colleagues from Kansas and Glasgow to Dublin, where they installed two powerful CERN detectors (known as LGAD and Medipix) in the medical linear accelerator that is used for radiotherapy at St. Luke's hospital. These detectors are 100 million times faster and have better image quality than technologies currently used in medical settings.   

Analysis of data from the LGAD detector showed new features of the particle beam: individual electrons were observed, and the pulse structure was resolved for the first time.  Having published these findings, the team was invited to install their LGAD detectors at the proton therapy machine in Krakow, one of only 14 in Europe, supported by a Horizon grant. Proton therapy is a new method for treating cancer: it is essentially a mini-LHC that uses a beam of protons to irradiate diseased tissue.

Here, the team demonstrated that the LGAD detectors can be used as dosimeters (devices that measure how much radiation the patient is exposed to) and to measure the beam energy. This is particularly important for FLASH therapy, an emerging technology for cancer treatment that involves an ultra-high dose of radiation, but that has not yet received patient approval, not least because standard detectors cannot measure the dose: the team’s detectors can.  

Following experience with the Medipix detector, a new team was established at the UCD Centre for Physics in Health and Medicine and St. Vincent's University Hospital to develop a device known as a Compton camera, which can image different organs at high resolution and search for tumours. Doing so requires that the patient is first injected with a small amount of radioactive material. This research shows that he Compton camera can produce images of far higher quality than existing methods, and does so with a radioactive dose to the patient estimated to be a factor 20 less.

Research impact

Technological impact

With this research, the team applied cutting-edge technology in new ways, and demonstrated the impact of doing so. They generated new knowledge through work on the medical linear accelerator at St. Luke's and the proton therapy machine in Krakow, where they made the first observation of the precise temporal structure of electron and proton beams used for patient treatment. 

The LGAD sensors used by the team have a time resolution 100 million times better than currently used technology, and provide proof of principle for a new dosimeter for FLASH therapy. New application of Medipix sensors have resulted in a Compton camera with a 20-fold sensitivity improvement over conventional cameras, thereby reducing radiation dose for the patient.

Health and economic impact

11,000 hospitals worldwide use medical linear accelerators, and there are 100 proton therapy centres. Every year they perform 30 million scans around the world. There is therefore substantial demand for improved imaging methods, and for new dosimetry techniques to facilitate FLASH therapy.

The potential impact of LGAD and Medipix technologies on healthcare is profound. The research team has shown that the new techniques they employed can generate images of organs with far more detail than existing cameras, which could significantly improve diagnosis and outcomes for cancer patients. What’s more, these imaging techniques can be performed far quicker than those currently used in hospitals, meaning more patients are able to be scanned over the same time period. Emerging cancer treatments – like FLASH – use brief but intense amounts of radiation, so being able to measure the patient’s dose is crucial, and the team has demonstrated how to do so more accurately.

In addition, this research has changed behaviour of health professionals through awareness and involvement in detector research with which they were unfamiliar.

Political impact

Ireland is one of just three EU countries that is not a member of CERN. By demonstrating how CERN detectors can be used outside of particle physics, this research has helped change government policy regarding CERN membership, with an announcement in November 2022 by Minister Harris that they were preparing a submission to join the organisation. The country formally applied for membership in late 2023, and may join CERN as early as June 2024.

Before this, the Director General of CERN visited St. Luke’s hospital to see how the linear accelerator was being used to treat cancer, and departmental officials visited CERN, where they were briefed on Medipix. The team’s work was presented in a debate of the Oireachtas Joint Committee on Business Enterprise and Innovation debate, featured in an Oireachtas briefing attended by Minister Harris, and was discussed with the Minister during an official visit to CERN, all of which helped to advocate for the value of Ireland joining one of the biggest scientific research centres in the world.

Educational impact

Through the research, three Irish, one American and two Polish students were trained in detector operation and data analysis.  Bill Kamtchou won the 2021 Irish Association of Physicists in Medicine Young Investigator Grant, and a prize for his talk at the European Congress of Radiology.

This work is of clear public interest, showing how frontier particle physics research can be applied in innovative ways for societal and health benefits, as evidenced by articles in the national media and policy-oriented magazines.

Academic impact

Three international research teams were established because of the research, involving experts from UCD, Kansas, St. Luke's hospital, IFJ Krakow, Glasgow and TUD. The project also fostered collaboration with the Medipix community, through the visit of spokesperson Michael Campbell to UCD in May 2022. Members of the team have presented results of their LGAD work at workshop in Turin, Zurich and Elba. Medipix results were presented at the European Congress of Medical Physics 2022, the European Association of Nuclear Medicine 2022, and the Radiological Society of North America Congress 2023.

The work has also opened up new channels of communication between standard electron therapy (in Dublin) and the emerging field of proton therapy (in Krakow), supported by management at St. Luke's.