ESTRO 2022

Session Item

Brachytherapy: Physics

Session Code: 7016

Session Type: Poster (digital)

Track: Brachytherapy

Primary standards and measurement methods for X-ray emitting electronic BT devices PRISM-eBT

Thorsten Schneider, Germany

Presentation Number: PO-1801

Abstract

Abstract Title:

Primary standards and measurement methods for X-ray emitting electronic BT devices PRISM-eBT

Authors:

Thorsten Schneider¹, Rolf Behrens¹, Fernando Garcia-Yip², Kari Tanderup³, Gustavo Kertzscher⁴, Jacob Johanson⁴, Peter Georgi⁴, Valentin Blideanu⁵, Christel Stien⁶, Johann Plagnard⁷, Jaroslav Solc⁸, Vladimir Sochor⁹, Massimo Pinto¹⁰, Thorsten Sander¹¹, Anna Subiel¹¹, Clare Gouldstone¹¹, Leon de Prez¹², Frank Verhaegen¹³, Brigitte Reniers¹⁴, Paz Avilés Lucas¹⁵, Zakithin Msimang¹⁶, David J Eaton¹⁷, Frank Weigand¹⁸, Mark J. Rivard¹⁹

¹Physikalisch-Technische Bundesanstalt (PTB), Dosimetry for Brachytherapy, Braunschweig, Germany; ²Physikalisch-Technische Bundesanstalt (PTB), Dosimetry for Brachytherapy , Braunschweig, Germany; ³Aarhus University Hospital, Radiation Therapy, Aarhus, Denmark; ⁴Aarhus University Hospital, Radiation Therapy , Aarhus, Denmark; ⁵Commissariat à l’énergie atomique et aux énergies alternatives, CEA, Paris, France; ⁶Commissariat à l’énergie atomique et aux énergies alternatives, CEA , Paris, France; ⁷Commissariat à l’énergie atomique et aux énergies alternatives , CEA , Paris, France; ⁸Cesky Metrologicky Institut, CMI, Brno, Czech Republic; ⁹Cesky Metrologicky Institut, CMI , Brno, Czech Republic; ¹⁰Agenzia Nazionale per le Nuove Tecnologie, l’Energia e lo Sviluppo Economico Sostenibile (ENEA), Istituto Nazionale di Metrologia delle Radiazioni ionizzanti, Casaccia, Italy; ¹¹NPL Management Limited, NPL, Teddington, United Kingdom; ¹²VSL B.V., VSL, Delft, The Netherlands; ¹³Stichting Maastricht Radiation Oncology Maastro Clinic , MAASTRO clinic, Maastricht, The Netherlands; ¹⁴Hasselt University, Universiteit Hasselt , Diepenbeek, Belgium; ¹⁵National Metrology Institute of Spain, LMRI-CIEMAT, Madrid, Spain; ¹⁶International Atomic Energy Agency, IAEA, Wien, Austria; ¹⁷ Guy’s and St Thomas’ Hospitals, London, United Kingdom & School of Biomedical Engineering & Imaging Sciences, King’s College London, Department of Medical Physics, London, United Kingdom; ¹⁸Carl Zeiss Meditec AG, Meditec, Oberkochen, Germany; ¹⁹Brown University, Dept. Radiation Oncology, Providence, RI,, USA

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Purpose or Objective

Within the framework of the European Metrology Programme for Innovation and Research (EMPIR), six European National Metrology Institutes (NMIs) together with four additional partners from universities and clinics are collaborating in a Joint Research Project PRISM-eBT to establish a harmonised, simplified, and traceable dosimetry for electronic brachytherapy (eBT) in terms of absorbed dose to water.

Material and Methods

The project is composed of four Workpackages (WP):

WP1’s aim is to establish primary standards for the absorbed dose rate to water for eBT devices at 1 cm depth in water, and to establish transfer instruments and corresponding measurement procedures for the dissemination of this quantity to clinical practice.

In WP2, a dosimetric methodology for skin eBT is being established with traceability to a primary standard developed in WP1.

In WP3, detectors and measurement instruments suitable for the determination of 3D dose distributions in water by eBT devices are characterised to develop a standardised traceable calibration process.

With these detectors, traceable dosimetry to determine 3D dose distributions in water is being established in WP4 to provide availability for the end-user community.

Results

Established primary standards, methodologies for traceability, and detectors characterization are highlighted and discussed in the presentation.
E.g. a catalogue of eBT and eBT-equivalent X-ray photon fluence spectra was compiled from data available in literature, obtained from manufacturers, and measured or created during the project. The catalogue is available on the project website and it provides a basis for spectrometry and dosimetry of eBT sources. Using a plastic scintillator detector, the dose profile and depth-dose curve for an eBT source were determined with a precision better than 2.5%. It will be discussed which methods have proven to be successful and which methods were withdrawn from additional consideration.

Conclusion

An outlook will be given which further results might be achieved by the end of the project at the end of 2022.

ACKNOWLEDGEMENT
This project 18NRM02 PRISM-eBT 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.