ESTRO 2020 Abstract book

S258 ESTRO 2020

Plenary Session: HIghlights of Proffered papers

OC-0437 MRI guided adaptive brachytherapy in locally advanced cervical cancer: overall results of EMBRACE I R. Pötter 1 , K. Tanderup 2 , M. Schmid 1 , C. Haie-Meder 3 , L.U. Fokdal 2 , A. Sturdza 1 , P. Hoskin 4 , U. Mahantshetty 5 , B. Segedin 6 , K. Bruheim 7 , F. Huang 8 , B. Rai 9 , R. Cooper 10 , E. Van der Steen-Banasik 11 , E. Van Limbergen 12 , B. Pieters 13 , L.T. Tan 14 , R. Nout 15 , A.C. De Leeuw 16 , N. Nesvacil 1 , K. Kirchheiner 1 , I. Jürgenliemk-Schulz 16 , C. Kirisits 1 , J.C. Lindegaard 2 , C.G. Embrace 17 1 Medical University Vienna, Department of Radiation Oncology, Vienna, Austria ; 2 Aarhus University Hospital, Department of Oncology, Aarhus, Denmark ; 3 Gustave- Roussy, Department of Radiotherapy, Villejuif, France ; 4 Mount Vernon Hospital, Mount Vernon Cancer Centre, Northwood, United Kingdom ; 5 Tata Memorial Hospital, Department of Radiation Oncology, Mumbai, India ; 6 Institute of Oncology Ljubljana, Department of Radiotherapy, Ljubljana, Slovenia ; 7 The Norwegian Radium Hospital- Oslo University Hospital, Department of Oncology, Oslo, Norway ; 8 Cross Cancer Institute and University of Alberta, Department of Oncology, Edmonton, Canada ; 9 Postgraduate Institute of Medical Education and Research, Department of Radiotherapy and Oncology, Chandigarh, India ; 10 St James's University Hospital, Leeds Cancer Centre, Leeds, United Kingdom ; 11 Radiotherapiegroep Arnhem, Department of Radiotherapy, Arnhem, The Netherlands ; 12 UZ Leuven, Department of Radiation Oncology, Leuven, Belgium ; 13 Amsterdam UMC- Academic Medical Center- University of Amsterdam, Department of Radiation Oncology, Amsterdam, The Netherlands ; 14 Addenbrooke´s Hospital- Cambridge University Hospitals, Department of Oncology, Cambridge, United Kingdom ; 15 Leiden University Medical Center, Department of Radiation Oncology, Leiden, The Netherlands ; 16 University Medical Centre Utrecht, Department of Radiation Oncology, Utrecht, The Netherlands ; 17 EMBRACE Collaborative Group, EMBRACE Collaborative Group, EMBRACE Collaborative Group, Austria Purpose or Objective To present mature overall clinical results from the prospective observational multi-centre IntErnational study on MRI-guided BRAchytherapy in locally advanced CErvical Cancer (EMBRACE). Material and Methods Data from 1416 pts with locally advanced cervical cancer (LACC) stage IB-IVA and IVB (in paraaortic nodes (PAN)) treated 2008-2015 in 23 centres were prospectively collected. Treatment comprised definitive EBRT (3DCRT or IMRT) and concurrent cisplatin followed by MR image guided adaptive brachytherapy (IGABT) based on MRI with applicator in situ. IGABT targets, OAR and dose volume parameters were reported following GEC-ESTRO recommendations (2005). EBRT dose was 45-50Gy (1.5- 2.0Gy/fraction). IGABT doses were prescribed according to institutional guidelines. A comprehensive QA programme was applied. Actuarial (Kaplan–Meier) estimates for the first recurrence/vital status (before 15/07/2019) were calculated at 3/5 years for local control (LC), pelvic control (PC), disease control (DC, any recurrence), overall survival (OS) and disease-free survival (DFS, any recurrence or death). Toxicity was prospectively assessed (CTCAEv3.0). Results This abstract is part of the media programme and will be released on the day of its presentation

Fig. 1 A single pin, 3x3 pins test model and the 3D RM for Al (upper panel); Resin vs Al FLUKA dose distributions (middle/lower panel).

Fig. 2 A target contour slice with overlaid dose (upper panel left), Y-Z and X-Y resin vs Al FLUKA isodose distributions and a DVH comparison. Conclusion A state-of-the-art metal 3D printing machine can be a viable method to manufacture complex 3D RMs from Al with high accuracy, mechanical stability and dosimetric properties similar to PMMA. Further research is needed to assess the limits of the newly proposed technique and validate the MC simulations with measurements.