Development of a multipurpose small animal phantom for pre-clinical radiotherapy studies

The initial aim of the project is to establish a commercial dosimetry service for pre-clinical radiobiology studies which will i)
improve the data and accuracy of experiments via provision of state of the art dosimetry, ii) reduce the total number of
animals used and iii) provide a novel 3D tissue-based platform for study of radiosensitizers.
This will be achieved through the development of standardized dosimetry protocols that will reduce dose uncertainties, and
the development of a multipurpose small animal phantom. A number of different irradiation units are currently employed
across the UK using their own dosimetry schedules, therefore as part of establishing the new service a comprehensive
audit of current practices will be undertaken. Due to the steep dose responses in radiation studies a 5% reduction in dose
uncertainty would roughly halve the number of animals required to achieve the same statistical relevance. The definition of
standards and quality assurance procedures for radiobiological studies will help regulate preclinical radiotherapy activities.
This will increase the confidence of clinical researchers and the funding bodies in such methods, as well as opening new
market opportunities for dosimetry services offered by the National Physics Laboratory (NPL). The proposed new
dosimetry service for pre-clinical imaging will scale-down established methodologies from the clinical to provide confidence
and accuracy for pre-clinical work, bringing the latter up to the same standard as the existing provision for patients. As a
major supplier of x-ray equipment, Xstrahl Ltd will benefit from an increase in radiobiological studies as the economic and
methodological barriers to entry are lowered.
A unique type of phantom will also be developed that is capable of housing a bespoke microfluidic device, containing a
tissue biopsy that will offer an alternative in vivo-like option for radiation-drug synergistic studies. The phantom will contain
tissues slices, e.g. 4mm x 4mm x 0.2mm from xenograft models or human biopsies and these can then be used to
measure the effects of irradiation with or without drugs, under precisely controlled conditions. Furthermore these tissue studies will incorporate all the improved dosimetry measurements thus significantly improving the experimental accuracy.
The project addresses issues identified by research organisations, funding bodies and the clinical community and opens up
new business opportunities for NPL, improvements in technology for Xstrahl Ltd and licensing or spin-out options for the
University of Hull.

The National Physics Laboratory (NPL) aims to develop and implement a traceable dosimetry service for pre-clinical
radiobiological studies for both the commercial and research markets. The service will include dosimetry traceability to
national standards, full source characterization, specific Quality Assurance procedures and in vivo dose verification based
on an innovative phantom with the option of encompassing a microfluidic device. The principle impact of the project will be
with the large radiobiological and pre-clinical research centres. There are ~10 main radiobiological centres in the UK and
over 50 research units performing radiation related research. Eight of the 15 CR-UK supported centres have radiationbased
research as a key aspect of their treatment strategies. In addition, many Commercial Research Organisations
(CRO) such as Epistem as well as the main radiobiological centres, have bases in Germany, Sweden, Netherlands, Italy,
and France. Over 140 centres were represented at the last European Radiation Research Society and the H2020 portfolio
for radiobiological work in EU is >Euro15M/year. Provision of a dosimetry service to satisfy regulatory compliance and
improve the research value will generate higher quality data, at a lower cost and using less animal experimentation.
Opening up NPL's dosimetry services to a new market will increase sales to NPL;. with a projected increase in sales of up
to £250k/year in the first years of the new service. Since there is no such service or platform currently available on the
world-wide market, this represents an excellent opportunity for NPL in terms of offering new services and increasing the
highly-skilled UK work-force.

The work will also have a major impact on the manufacturers of radiation facilities; who will benefit from the dosimetry
service for adherence to specification compliance. The X-ray irradiator for scientific and industrial research laboratory
market is dominated by Xstrahl (the project partner), Faxitron, Precision X-ray and Rad Source each currently supplying
~1000s cabinet systems worldwide. Moreover, they provide a range of collimators, filters, animal retainers and chambers
which will affect the dose absorbed by the animal/sample therefore requiring specific measurement and dose validation.
These companies will benefit from the increased awareness of the importance of radiation dosimetry and adjunct credibility
in radiation products and core services for both new and existing pre-clinical sites. The new tissue based phantoms will
provide a platform that allows biomedical researchers to undertake radiobiology research without the need for substantial
investment in large animal facilities and irradiation equipment. The validated dosimetry and accurate monitoring mean that
fewer animal experiments will be required to obtain the same level of data, and most importantly the technology
encourages the replacement of animals where human tissue is available, helping the UK stay at the forefront of research
whilst fully adopting the NC3Rs ethos.
Regulatory bodies have previously highlighted the need for standardization of pre-clinical work, the outcomes of the
proposed work will provide both a knowledge framework and also the monitoring service that can deliver the technology.
As part of the project there will be early engagement with the appropriate authorities to ensure that all the relevant data are
gathered and that the findings can quickly transform and improve the radiobiology field. It is envisaged that changes can
be made within two years of the project's completion.