FINAL SCIENTIFIC WORKSHOP for stakeholders took place in December 2022. The final workshop has it own dedicated website with all relevant information. Its aim was to present the progress of the project to stakeholders from the clinical, scientific, and manufacturing sector, standardisation bodies, and other interested parties.

The dissemination workshop took place on 7 December 2022. Summary presentation on PRISM-eBT project results is available here.

Catalogues of X-ray photon fluence spectra generated by electronic brachytherapy devices and their eBT-equivalent spectra realizable in laboratories with common X-ray tubes were published in section Impact.


This project has received funding from the EMPIR programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.

EURAMET website of the Project is here.

About this project

Primary standards and traceable measurement methods for X-ray emitting electronic brachytherapy devices (PRISM-eBT) is a joint research project within the European Metrology Programme for Innovation and Research (EMPIR). The project began on 1 July 2019 and will run for three and a half years, finishing on 31 December 2022. The overall goal of this project is to carry out pre-normative research on electronic brachytherapy (eBT) to simplify and harmonise eBT dosimetric procedures and provide metrological input to standardisation bodies. The Chief stakeholder of the project is the International Atomic Energy Agency.

Download Publishable SummaryAdobe Acrobat file of the project.

The specific objectives are:

  1. To establish primary standards for the absorbed dose rate to water for eBT devices at 1 cm depth of water for internal radiotherapy. To evaluate currently used transfer instruments and corresponding measurement procedures and to establish simple and robust tools for dissemination of the absorbed dose rate to water to clinical practice.
  2. To establish a dosimetric methodology for superficial eBT aligned with or similar to the recommendations for superficial (skin) external radiotherapy given in International Atomic Energy Agency – Technical Reports Series (IAEA-TRS) 398, Deutsches Institut für Normung (DIN) 6809-4, Nederlandse Commissie voor Stralingsdosimetrie (NCS)-10 and Institute of Physics and Engineering in Medicine (IPEM). The target uncertainty for the conversion of dose at the surface (i.e. 70 μm) to dose at 1 cm depth is 5 %.
  3. To characterise detectors and measurement instruments suitable for the determination of 3D dose distributions in water by eBT devices. To develop a standardised traceable calibration process for these detectors, allowing a reduction in the uncertainties in dose, dose distribution and dose-effectrelation to a level recommended in IAEA Human Health Report No 31. The aim is to achieve uncertainties (k = 1) for the calibration coefficients of not more than: 1 % – 2 % (NMIs) and 2 % – 3 % (clinic) for the scintillation detectors and for the small volume ionisation chambers, 3.5 % for the gel dosimeter and 2.5 % for the alanine pellets.
  4. To provide traceable dosimetry for 3D dose distribution measurements for at least three eBT commercial systems for which no dosimetry system currently exists and to make them available for the end user community.
  5. To contribute to the development of technical work of IAEA and others where appropriate to ensure that the outputs of the project are aligned with their needs, communicated quickly to those developing the standards and to those who will use them, and in a form that can be incorporated into the standards at the earliest opportunity.

The workpackage description is provided here and the project background is described here.

More detailed results from reports internal to the project may be made available to individual enquirers.