ESTRO 2023

Session Item

Saturday

May 13

16:45 - 17:45

Strauss 2

Physics

Chair: Asa Carlsson Tedgren, Sweden;

Co-Chair: Frida Dohlmar, Sweden

Session Code: 1560

Session Type: Proffered Papers

Track: Brachytherapy

17:06 - 17:15

GEC-ESTRO recommendations for commissioning a brachytherapy TPS

Marisol De Brabandere, Belgium

Presentation Number: OC-0292

Abstract

Abstract Title:

GEC-ESTRO recommendations for commissioning a brachytherapy TPS

Authors:

Marisol De Brabandere¹, Luc Beaulieu², Mauro Carrara³, Catherine Dejean⁴, Claire Dempsey⁵, Chris Lee⁶, Joshua Mason⁷, Mark J Rivard⁸, Jose Perez-Calatayud⁹, Ryan Smith¹⁰, Jacco Steenhuijsen¹¹, Renate Walter¹², Geraldine Workman¹³, Anysja Zuchora¹⁴, Frank-Andre Siebert¹⁵

¹University Hospital Leuven, Dept of Radiation Oncology , Leuven, Belgium; ²Université Laval, Faculty of Science and Engineering, Québec, Canada; ³IAEA, Division of Human Health, Vienna, Austria; ⁴Centre Antoine-Lacassagne, Dept. Medical Physics, Nice, France; ⁵Calvary Mater Newcastle, School of Health Sciences, Newcastle, Australia; ⁶Clatterbridge Cancer Centre, Department of Medical Physics, Liverpool, United Kingdom; ⁷Imperial College Healthcare NHS Trust, Dept. Radiation Oncology, London, United Kingdom; ⁸Alpert Medical School of Brown University, Dept. of Medical Physics, Providence, RI, USA; ⁹La Fe Hospital, Radiotherapy Department, Valencia, Spain; ¹⁰The Alfred Hospital, Dept. of Radiation Oncology, Melbourne, Australia; ¹¹Catharina Hospital Eindhoven, Dept. of Radiation Oncology, Eindhoven, The Netherlands; ¹²University Hospital Augsburg, Dept. of Radiation Oncology, Augsburg, Germany; ¹³Northern Ireland Cancer Centre, Dept. of Radiation Oncology, Belfast, United Kingdom; ¹⁴University Hospital Galway, Medical Physics and Bioeengineering, Galway, Ireland; ¹⁵UKSH, Clinic of Radiotherapy / Campus Kiel, Kiel, Germany

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Purpose or Objective

Brachytherapy (BT) treatment planning systems (TPS) are indispensable tools for computing the dose distribution and treatment time of brachytherapy patient plans. For a safe treatment it is essential that source data, calculation parameters, and planning functionalities affecting the TPS output are modelled and/or validated properly. Currently there are only a few dedicated societal reports available to guide users through the commissioning process of a BT TPS. The GEC-ESTRO BRAPHYQS working group in cooperation with the AAPM is working on a report with practical recommendations for TPS commissioning for HDR/PDR BT as well as LDR seed implant BT TPS.

Material and Methods

The BRAPHYQS working group was extended with further experts in the field for this project. After extensive literature research and internal discussions, an outline and sections were defined. Due to the high availability and use worldwide, this report focuses on TG-43-based algorithms only; for advanced model-based dose calculation algorithms, the users are referred to existing reports such as TG-186. Five main subtopics have been defined to guide the commissioning process: (a) geometry and imaging, (b) source specification, (c) dose calculation accuracy and representation, (d) (library) applicator specification, and (e) output/data transfer and reporting.

Results

A set of commissioning tests was designed and summarized in tables per topic, including the frequency, tolerance, and possible tools and resources to be used. A CT-based DICOM set of a phantom with well-defined structures was prepared, allowing users to test image import, display and manipulation, as well as geometric properties and functionalities of the TPS. This DICOM set will be made available through the GEC-ESTRO/BRAPHYQS website. A range of imaging modalities used in modern BT is covered such as CT, MRI, and US. Furthermore, a selection of extensive tests is described in greater detail within the Appendices. The recommended tests in this report can be used at the time of TPS commissioning as well as after software upgrades or for annual constancy checks.

Conclusion

BRAPHYQS is finalizing the recommendations to validate the calculational accuracy and performance of HDR/PDR and LDR BT TPSs. This report will provide a comprehensive set of practical tools (tables/checklists, phantom data, detailed tests) to ensure high quality BT dosimetry calculations. It is aimed to finalize and publish the report in 2023.