WP4 - TG43
Chair: Facundo Ballester and José Perz-Calatyaud
The TG43 data of "conventional" brachytherapy sources -mainly 137Cs and 192Ir sources- are collected by the group at the University of Valencia. New sources or new source data can be added. Data are also included on low-energy photon emitting brachytherapy sources (125I, 103Pd) that comply with the prerequisites of AAPM TG-43. If consensus datatsets coud be obtained by the AAPM, these are included on the Estro web page. The contents are supervised by a BRAPHYQS expert team. A new entrance to the Braphyqs website data can be accessed. The BRAPHYQS group has written a short introductory text to the TG-43 data site with explanation on use and background information. Research data -which means: non-validated sets of TG43 data- will stay available using the 2nd website still located at the University of Valencia: http://www.uv.es/braphyqs. Transfer of the data from the http://www.uv.es/braphyqs site to this site has been done.
Some members of BRAPHYQS group are also members of the AAPM Brachytherapy Subcommittee (BTSC) and its working groups. In these positions, they represent the ESTRO community, reflected in an ESTRO’s co-sponsorship of the reports “Dosimetric prerequisites for routine clinical use of photon emitting brachytherapy sources with average energy higher than 50 keV” by Zuofeng Li et al., Med Phys. Dec 2007; 34:37-40) and “Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: Report of the AAPM and ESTRO” by Perez-Calatayud et al. Med. Phys. 39 (5), May 2012.
The coordination between BRAPHYQS group and the BTSC Subcommittee lead to a full consensus on the data of the Low-Energy as well High Energy Brachytherapy Dosimetry data, with an Internet presentation of such data using links from the ESTRO site to USA counterparts and vice versa.
WP5 - Calibration Facility for 125I
Chair: Frank-André Siebert
Calibration facilities for 125I and 103Pd sources with easy access for European institutes are lacking. Actually, in the world only NIST provides the user with a calibration facility and recently PTB Braunschweig (H.J. Selbach) has opened a WAFAC type 125I calibration facility. The purpose of the taskgroup is to further stimulate European primary and secondary standard labs in co-operation within EUROMET to develop such standards for these low-energy sources. Following a previous contact with PTB by Alex Rijnders, Jack Venselaar and Tony Aalbers (NMi NL), a small mini-symposium in parallel to the ESTRO 25 meeting in Leipzig (Oct 2006) was organized. Invitations were sent to representatives of different EU and USA labs and ABS (on behalf of BRAPHYQS, Jack Venselaar, Alex Rijnders, Heikki Toelli, Taran Paulsen Hellebust and José Pérez-Calatayud ). The meeting was successful and it was agreed that there is a need for cooperation between labs and “customers”. Several ideas were discussed and will be brought to the attention of the board of EURAMET. The EURAMET project T2.J06 is a project of European standard laboratories with the goal to establish dose-to-water calibration in brachytherapy. BRAPHYQS is cooperating with the EURAMET T2.J03 project group, offering the expertise of BRAPHYQS to this project. As chair of BRAPHYQS F.-A. Siebert is invited to the EURAMET meetings.
WP14: in vivo dosimetry
Chair: Kari Tanderup
In vivo dosimetry for brachytherapy is rarely used routinely in clinical practice today. The reason is the lack of dosimetry systems with a high enough accuracy to identify and prevent errors in treatment delivery. Currently, the benefit of using in vivo dosimetry is therefore very limited and many clinics are not performing it. The aim of WP14 is to advance the field in order to make in vivo a routine part of brachytherapy. Significant advances have been seen the last years in terms of developments of new dosimeter systems based on either point dosimeters or flat panels. Systems are now becoming available in research settings, which can provide information with such high precision that it becomes clinically relevant.
Furthermore, surveys have been sent to clinics to obtain information about the need and request for in vivo dosimetry, and to get insight into the type of incidences which an in vivo dosimetry system should be able to detect. Currently, a large survey on treatment verification is being prepared with the aim at distributing it to clinics across Europe in the summer of 2018. Furthermore, an ESTRO task group is working on a “White Paper” on the current status of in vivo dosimetry and requirements needed before in vivo dosimetry can be a part of the daily clinical brachytherapy practice - both for brachytherapy and external beam radiotherapy. This paper will be written before end of 2019.
WP17 - Dicon standard in brachytherapy
Chair: Yury Niatsetki
The goal of the WP 17 DICOM Standard in Brachytherapy is to improve interconnectivity between different planning systems in brachytherapy, facilitating plan comparison for clinical studies:
1) Evaluation of dose distributions used for treatment
2) Exchange of treatment plans between TPS of different vendors
3) Compare 3D treatment planning dose calculations
These are not fully covered in the currently used 1st generation DICOM RT objects because the those were developed more than 20 years ago.
BRAPHYQS group is one of the stakeholders of the DICOM WG-07 Brachytherapy Subgroup, working on 2nd generation DICOM RT objects and on the IHE-RO (Integrating the Healthcare Enterprise – Radiation Oncology) Brachytherapy Workflow profile, addressing solutions for interconnectivity issues using the DICOM objects provided in its 1st generation.
WP19: Quality Control of Brachytherapy Treatment Planning Systems
Chair: Marisol De Brabandere and Alex Rijnders
Currently there are no dedicated, practical reports available on commissioning and quality assurance (QA) of treatment planning systems (TPS) for brachytherapy. Most of the existing reports and handbooks on TPS commissioning are either too concise or too theoretical, or are focusing on external beam therapy only. The aim of the WP19 project is
1) to provide users with guidelines for commissioning and quality assurance (QA) of brachytherapy treatment planning systems at the time of implementation and after minor and major software upgrades/updates;
2) to provide a set of practical tools (spreadsheets, DICOM sets, checklists, …) to validate the TPS calculation accuracy and performance.
Unlike other work packages within BRAPHYQS, WP19 is an open project with support of non-BRAPHYQS members. An appeal for contributors was made in 2017, resulting in a group of brachytherapy physicists from all over Europe. Representatives from the American Association of Physicists in Medicine (AAPM) and Australasian Brachytherapy Group (ABG) are included. In spring 2018 an application for ACROP approval was submitted to ESTRO.
Five main subtopics have been defined for this report: (a) geometry and imaging, (b) source and afterloader specification, (c) dose calculation accuracy and representation, (d) (library) applicator specifications and (e) output/data transfer and reporting. For each topic a coordinator and several contributors were assigned. The guidelines will handle both HDR/PDR/LDR and seed implant brachytherapy. It will focus on TG43-based algorithms only, as an AAPM working group is currently preparing a separate report on advanced MC-based dose calculation algorithms. Commissioning and quality control of image fusion will not be discussed in detail because of a Braphyqs review being prepared simultaneously on this topic. Commissioning of applicator reconstruction will be handled briefly, as in 2007 GEC-ESTRO recommendations were already published on applicator commissioning with detailed guidelines and examples. Eye plaque calculation and iridium-192 wire calculation are both excluded from the WP19 project.
WP20 Image Matching in Brachytherapy
Chair: Cristian Kirisits
Image registration, image matching and dose accumulation are important topics for brachytherapy. The matching of target volumes between different image modalities and images taken at different time points is challenging. Also the dose accumulation between fractionated brachytherapy treatments and combination with external beam has been topic of many analysis and recommendations. However, there are several misunderstandings when transferring models created for external beam to brachytherapy applications. This workpackage analysis the existing methods, the evidence from scientific and technical literature and would like to draw conclusions including expert opinions.