A smart imaging sensor for real time transit dosimetry in radiotherapy

Lead Research Organisation: University College London
Department Name: Medical Physics and Biomedical Eng

Abstract

Radiotherapy treatment is delivered to over half of cancer patients, and due to the ageing population and lifestyle factors the prevalence of cancer is rising. EPIDs (electronic portal imaging devices) are used during the treatment delivery process to control patient set-up and positioning. The demand for accurate treatment verification has led to the possibility of using EPIDs to acquire dosimetric information.
Recent government guidelines require that each radiotherapy centre should have protocols for in vivo dosimetry monitoring and that it should be used at the beginning of treatment for most patients. Within the radiotherapy physics community EPID dosimetry is widely seen to have the potential to become an accurate and efficient means of large-scale patient specific in-vivo dose verification for Intensity Modulated RadioTherapy at any radiotherapy department.
Current EPID technology is based upon passive amorphous silicon flat panel imagers. In this proposal we plan to investigate the application of next generation sensor technology, developed by the STFC CMOS Sensor Design Group, which has both superior image quality and active functionality.
We propose to carry out a feasibility study with a long-term view to developing the following transit dosimetry technology: a large area, ultra high image quality flat panel imager displaying real-time, calibrated dose map updates throughout treatment delivery. The core of the system will be an STFC developed CMOS Active Pixel Sensor. It will not only introduce large area, radiation hard CMOS technology to EPID systems but will go a significant step further and introduce next generation Active Pixel Sensor technology.

Planned Impact

Who will benefit from this research and how?

Department of Health policy makers - The department of health have made recommendations to all radiotherapy departments in the UK to implement in-vivo dosimetry methods. One recommendation is that IMRT would benefit from transit dosimetry and that research into this field should be encouraged and supported. This proposal aims to do exactly that and so will help to work towards safer radiotherapy for the UK and beyond.

Radiotherapy community - The radiotherapy community is actively implementing in-vivo dosimetry methods, including transit dosimetry. Currently centres are implementing methodologies which uses EPID technology that was designed and built for a different purpose, namely patient set-up and localisation. Consequently, the performance of current EPIDs is not matched to that required for transit dosimetry and there is a complete absence of any built-in functionality or programmable features that lend themselves to developing an automated, efficient technology that operates with minimal disruption to the clinical workflow. It is a common problem in radiotherapy that as the demand for more sophisticated radiotherapy increases and more technological solutions are introduced then it has a negative impact on patient throughput. We aim to counter this by introducing new technology with a programmable interface and built-in functionality to enable self-calibration, automated procedures, continuously updating display presenting the information needed in the most appropriate format without the need for post treatment analysis, and so on.

Patient groups - The Department of Health aim in recommending the introduction of in-vivo dosimetry and research into transit dosimetry was to make radiotherapy safer for the patient. The Case for Support refers to a report from the Netherlands whereby 17 serious errors were detected using transit dosimetry in the treatment delivery plan within a cohort of just over 4000 patients. Our aim is to introduce technology with superior performance and an application specific set of features and functionality to enable easy integration of such systems into the clinic.

Academic community - Novel large area, radiation hard, functional, sensor technology is applicable to a wide range of academic communities beyond radiotherapy, from medical imaging and monitoring, through to space science, particle physics and industrial imaging. Via wide dissemination we hope to introduce the technology to other disciplines and stimulate further research into such technological solutions. A key interest of the project consortium is to promote extensive research into solving the issues currently facing in-vivo dosimetry and work towards a verifiable radiotherapy solution.

Publications

10 25 50
publication icon
Ricketts K (2016) Clinical Experience and Evaluation of Patient Treatment Verification With a Transit Dosimeter. in International journal of radiation oncology, biology, physics

 
Description This was a preliminary study to assess the potential of novel sensor technology for imaging and dosimetric applications in radiotherapy. The success of this programme fed into a subsequent successful grant application to develop and apply the technology further. The work is on-going and generating useful output.
Exploitation Route The work has been continued in a subsequent grant and is still under development.
Sectors Healthcare

 
Description CLASP
Amount £360,000 (GBP)
Funding ID ST/M007855/1 
Organisation Science and Technologies Facilities Council (STFC) 
Sector Public
Country United Kingdom
Start 06/2015 
End 05/2017
 
Title Transit dosimetry for radiotherapy 
Description A considerable set of image data has been collected for the use of the novel imaging sensor in a radiotherapy treatment beam. It is been fully analysed and interpreted to characterise the sensor performance and used to predictively model the performance of next generation imaging sensor technology. 
Type Of Material Database/Collection of data 
Year Produced 2015 
Provided To Others? Yes  
Impact Proof of concept of novel imaging sensor technology applied to transit dosimetry in radiotherapy. 
 
Description This project is done in collaboration with STFC Rutherford Appleton Laboratory. 
Organisation Elekta Inc
Country Sweden 
Sector Private 
PI Contribution We specified the clinical design criteria for medical imaging sensors designed and produced by Rutherford Appleton Laboratory, Subsequently we have tested their performance characterstics and benchmarked against competing technologies. In addition we have researched applications for these sensors in radiotherapy.
Collaborator Contribution Rutherford Appleton Lab have designed and fabricated novel CMOS imaging sensors. Elekta provides commercial guidance on the direction of the product.
Impact The work is undergoing. To date the sensors have been designed, fabricated and partially tested. Currently second level testing is on-going and new applications are being developed.
Start Year 2015
 
Description This project is done in collaboration with STFC Rutherford Appleton Laboratory. 
Organisation Rutherford Appleton Laboratory
Country United Kingdom 
Sector Academic/University 
PI Contribution We specified the clinical design criteria for medical imaging sensors designed and produced by Rutherford Appleton Laboratory, Subsequently we have tested their performance characterstics and benchmarked against competing technologies. In addition we have researched applications for these sensors in radiotherapy.
Collaborator Contribution Rutherford Appleton Lab have designed and fabricated novel CMOS imaging sensors. Elekta provides commercial guidance on the direction of the product.
Impact The work is undergoing. To date the sensors have been designed, fabricated and partially tested. Currently second level testing is on-going and new applications are being developed.
Start Year 2015
 
Description Transit dosimetry for radiotherapy 
Organisation Dosisoft
Country France 
Sector Private 
PI Contribution We formulated the concept of the research project and carried out the majority of the research (including design, data taking, analysis).
Collaborator Contribution Royal Berkshire NHS foundation trust - provided clinical radiotherapy expertise and the facilities for testing the concepts and the technology. STFC Rutherford Appleton Laboratory - provided the imaging sensor technology and the technical expertise for operating it. Dosisoft - a commercial company that produces software for this particular clinical application, transit dosimetry. They provided technical input.
Impact The research has proven the concept that superior information can be achieved by applying novel imaging sensor technology to transit dosimetry. The research is on-going via a follow-on grant. The initial award was a short, proof-of-concept award. The follow-on grant will reap the benefits of the proven concept and generate significant output.
Start Year 2014
 
Description Transit dosimetry for radiotherapy 
Organisation Royal Berkshire NHS Foundation Trust
Country United Kingdom 
Sector Public 
PI Contribution We formulated the concept of the research project and carried out the majority of the research (including design, data taking, analysis).
Collaborator Contribution Royal Berkshire NHS foundation trust - provided clinical radiotherapy expertise and the facilities for testing the concepts and the technology. STFC Rutherford Appleton Laboratory - provided the imaging sensor technology and the technical expertise for operating it. Dosisoft - a commercial company that produces software for this particular clinical application, transit dosimetry. They provided technical input.
Impact The research has proven the concept that superior information can be achieved by applying novel imaging sensor technology to transit dosimetry. The research is on-going via a follow-on grant. The initial award was a short, proof-of-concept award. The follow-on grant will reap the benefits of the proven concept and generate significant output.
Start Year 2014
 
Description Transit dosimetry for radiotherapy 
Organisation Rutherford Appleton Laboratory
Department CMOS sensor design group (Rutherford Appleton)
Country United Kingdom 
Sector Public 
PI Contribution We formulated the concept of the research project and carried out the majority of the research (including design, data taking, analysis).
Collaborator Contribution Royal Berkshire NHS foundation trust - provided clinical radiotherapy expertise and the facilities for testing the concepts and the technology. STFC Rutherford Appleton Laboratory - provided the imaging sensor technology and the technical expertise for operating it. Dosisoft - a commercial company that produces software for this particular clinical application, transit dosimetry. They provided technical input.
Impact The research has proven the concept that superior information can be achieved by applying novel imaging sensor technology to transit dosimetry. The research is on-going via a follow-on grant. The initial award was a short, proof-of-concept award. The follow-on grant will reap the benefits of the proven concept and generate significant output.
Start Year 2014
 
Title Imaging sensor for transit dosimetry for radiotherapy 
Description Proof of concept stage completed for the use of novel imaging sensors to aid treatment verification during radiotherapy procedures. Follow-on funding is underway (STFC CLASP award) to continue development to next stage - including next generation of technology and clinical testing. 
Type Therapeutic Intervention - Radiotherapy
Current Stage Of Development Initial development
Year Development Stage Completed 2016
Development Status Under active development/distribution
Impact The technology is a high performance, adaptable imaging sensor, which can potentially be applied to other areas in radiotherapy and other areas of imaging (both in the healthcare field and in other fields requiring x-ray imaging). 
 
Title Imaging sensor for transit dosimetry in radiotherapy 
Description A CMOS imaging sensor for verifying the radiation dose delivered to a cancer patient undergoing a radiotherapy treatment. 
Type Of Technology Detection Devices 
Year Produced 2016 
Impact Proof of concept that novel CMOS imaging sensor technology can improve the treatment verification of radiotherapy patients.