Robust Permanent Magnet Beam Delivery Systems for Medical Radiotherapy Linacs
Lead Research Organisation:
University of Oxford
Department Name: Oxford Physics
Abstract
This proposal forms part of an initiative to design a linear electron accelerator for radiotherapy where all subsystems will be optimised to ensure it is robust, reliable, cost effective and appropriate for use in challenging environments including developing countries. This project aims to design a beam delivery system (magnetic focusing and steering) which uses modern capabilities in permanent magnets to ensure that a high-quality electron beam can be taken from the source to the x-ray generating target with minimal losses. Replacing some or all of the existing electromagnets with permanent magnets should enable a maintenance-free focusing system which requires very little electricity, which has been highlighted as a barrier to providing this technology in ODA countries. (A few smaller, cheaper and replaceable adjustable electromagnets will be included for fine tuning, which would have minimal power requirements.)
Planned Impact
In September 2015, the Global Task Force on Radiotherapy for Cancer Control (GTFRCC) released a comprehensive study of the global demand for radiation therapy*. It highlighted the inadequacy of current equipment coverage and the resources required, as well as the costs and economic and societal benefits of improving that coverage. The GTFRCC report estimated that as many as 12,600 megavolt-class treatment machines will be needed to meet radiotherapy demands in Low to Middle Income Countries (LMICs) by 2035. This proposal forms part of the wider initiative to design a novel LINAC for challenging environments. The provision of a new, compact and robus radiotherapy LINAC has the potential to benefit millions of people in LMICs.
*http://www.thelancet.com/commissions/global-cancer-surgery
*http://www.thelancet.com/commissions/global-cancer-surgery
Organisations
- University of Oxford (Lead Research Organisation)
- Life Gaborone Private Hospital (Collaboration)
- National Hospital Abuja (Collaboration)
- Universitas Indonesia (Collaboration)
- European Organization for Nuclear Research (Project Partner)
- Science and Technology Facilities Council (Project Partner)
- King's College London (Project Partner)
Publications
Konoplev I
(2020)
Ultimate energy recovery from spent relativistic electron beam in energy recovery linear accelerators
in Physical Review Accelerators and Beams
Wroe L
(2020)
Comparative Analysis of Radiotherapy Linear Accelerator Downtime and Failure Modes in the UK, Nigeria and Botswana
in Clinical Oncology
| Description | A simulation model of the effects of different types of permanent magnets and their effects in radiotherapy LINACs was developed. A prototype magnet was designed, built and measured. It was found that there are no serious barriers at this stage to using permanent magnets in this type of machine for beam focusing or bending, if required, and that the requirements on tolerances are relatively relaxed. Small adjustments to beam position would still need to be provided by electromagnets. Further to the original aims, the project was extended to look at failure modes and failure rates of different LINAC subsystems, and a tool was created which can analyse accelerator availability based on data now being collected. This will underpin future efforts toward robust accelerators for low and middle-income countries. |
| Exploitation Route | The simulation pipeline created can be taken forward in future work toward robust radiotherapy accelerators. The magnet designs can be built upon to make them more precise and work toward a first prototype to be used with real beams. The failure mode and failure rate data and model can be used by a wide range of researchers to understand the problems facing users of LINACs in low and middle-income countries to help take a data-driven approach to future innovations. |
| Sectors | Healthcare |
| Description | The findings from this study have already been used by researchers in Nigeria to better understand the challenges faced in radiotherapy provision in the wider context of the health system, which is expected to generate impact in the effectiveness of public health services. In addition to LMIC impact, a number of public and schools presentations by the researchers in the UK have led to increased awareness of the global shortfall in radiotherapy accelerators among the public and researchers in other discipline, and this is expected to leaded to long-term impact toward solving this global challenge. |
| First Year Of Impact | 2020 |
| Sector | Healthcare |
| Impact Types | Policy & public services |
| Description | Impact Acceleration Account - Growing a UK network to realise impact for a robust medical LINAC for challenging environments |
| Amount | £17,600 (GBP) |
| Organisation | Science and Technologies Facilities Council (STFC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 08/2019 |
| End | 09/2020 |
| Description | University of Oxford Impact Acceleration Account |
| Amount | £10,000 (GBP) |
| Organisation | University of Oxford |
| Sector | Academic/University |
| Country | United Kingdom |
| Start | 06/2019 |
| End | 07/2019 |
| Title | Availability modelling tool for generalised medical LINAC |
| Description | A generalised availability modelling tool was developed for medical LINACs. The tool was commissioned from Egerton Consulting, and uses a subsystem breakdown of the technology to assess availability based on Mean Time to Failure Data, restocking time for spare parts, redundancy etc... This will allow the wider collaboration to assess the impact of their proposed research projects on the overall availability of a medical LINAC. |
| Type Of Material | Improvements to research infrastructure |
| Year Produced | 2019 |
| Provided To Others? | No |
| Impact | The tool has not yet been circulated or made available to others, so impacts are not yet expected. |
| Title | Medical LINAC downtime database |
| Description | A database of failure modes and downtime collected from medical LINACs in Oxford (UK), Nigeria and Botswana, based on engineers log books. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2018 |
| Provided To Others? | No |
| Impact | This database has created an underlying statistical basis on which to build future research in the area of robust, modular medical LINACs. |
| Description | Collaboration with Indonesia for downtime data collection |
| Organisation | Universitas Indonesia |
| Country | Indonesia |
| Sector | Academic/University |
| PI Contribution | Oxford researchers have helped design an appropriate data collection methodology to enable LINAC downtime data collection from 15 hospitals across Indonesia. A workshop is planned for July 2019. Two University of Oxford staff gave lectures at Universitas Indonesia for around 50 masters-level students on Machine Learning in medical physics and on particle accelerators in medicine. |
| Collaborator Contribution | Universitas Indonesia (Depok Campus) Physics department collaborators have facilitated the collaboration, arranged meetings in hospitals in Jakarta with relevant experts, and brought together 15 hospitals around Indonesia who will collect downtime and failure mode data of medical LINACs. |
| Impact | No outputs yet, data collection ongoing. |
| Start Year | 2018 |
| Description | Collaboration with Nigeria & Botswana partners on downtime data |
| Organisation | Life Gaborone Private Hospital |
| Country | Botswana |
| Sector | Hospitals |
| PI Contribution | My student worked with collaborators to design a study to collect LINAC failure mode and downtime data. |
| Collaborator Contribution | Collaborators enabled data collection of downtime and failure mode data of medical LINACs in Nigeria and Botswana. |
| Impact | Database of linac downtime data. Multi-disciplinary: medical physics, engineering, accelerator physics, oncology. |
| Start Year | 2018 |
| Description | Collaboration with Nigeria & Botswana partners on downtime data |
| Organisation | National Hospital Abuja |
| Country | Nigeria |
| Sector | Hospitals |
| PI Contribution | My student worked with collaborators to design a study to collect LINAC failure mode and downtime data. |
| Collaborator Contribution | Collaborators enabled data collection of downtime and failure mode data of medical LINACs in Nigeria and Botswana. |
| Impact | Database of linac downtime data. Multi-disciplinary: medical physics, engineering, accelerator physics, oncology. |
| Start Year | 2018 |
| Title | pyASTRA tool for LINAC simulation |
| Description | pyASTRA is a python pre- and post-processor for the simulation code ASTRA (http://www.desy.de/~mpyflo/) This code will soon be made open access and available for other users (currently on Oxford's GitLab system) |
| Type Of Technology | Software |
| Year Produced | 2018 |
| Impact | N/A yet |
| Description | A-Level Science Live: Physics |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Schools |
| Results and Impact | Two talks given for audiences of 1000+ at major venues in Birmingham and London (Picadilly Theatre). Presentation included medical LINAC project. Description of the talk is: "There are over 35,000 particle accelerators in existence today, whose purposes vary from uncovering the secrets of the universe to treating cancer. Dr Suzie Sheehy talks about the incredible atom smashing machines." |
| Year(s) Of Engagement Activity | 2018 |
| URL | http://www.alevelsciencelive.net/speakers/dr-suzie-sheehy/ |
| Description | Physics: From the Lab into Your Life Event |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Public/other audiences |
| Results and Impact | Over 100 audience members watched a presentation delivered by myself and student (Laurence Wroe) about the applications of accelerators, and medical LINACs in developing countries. |
| Year(s) Of Engagement Activity | 2018 |
| URL | http://www.ox.ac.uk/event/physics-lab-your-life |
| Description | Royal Institution: Family talk |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Public/other audiences |
| Results and Impact | 250 audience members attended live demonstration talk at the Ri, London. Questions to the speaker lasted 1.5 hours after the talk (!) and audience members reported change in views and opinions re. curiosity driven research. Blurb: Join Suzie Sheehy to explore the exciting, atom smashing world of particle accelerators. With live demonstrations, she'll show how we design these fascinating machines, which let us interact and explore nature on the smallest scales. She'll also reveal how we use these machines in many unexpected - and useful - ways, helping us solve some of the greatest challenges facing people on Earth. |
| Year(s) Of Engagement Activity | 2019 |
| URL | https://www.rigb.org/whats-on/events-2019/february/family-colliding-worlds |