ESTRO 2023

Session Item

Monday

May 15

16:30 - 17:30

Plenary Hall

Reirradiation

Co-Chair: Arnaud Beddok, France;

Chair: Giulio Francolini, Italy

Session Type: Proffered Papers

Track: Clinical

Journey:

16:50 - 17:00

ESTRO/EORTC consensus definition of re-irradiation paving the way for the prospective ReCare cohort

Nicolaus Andratschke, Switzerland

Presentation Number: OC-0917

Abstract

Abstract Title:

ESTRO/EORTC consensus definition of re-irradiation paving the way for the prospective ReCare cohort

Authors:

Nicolaus Andratschke¹, Jonas Willmann², Ane Appelt³, Najlaa Alyamani⁴, Panagiotis Balermpas⁵, Brigitta Baumert⁶, Coen Hurkmans⁷, Morten Høyer⁸, Johannes Langendijk⁹, Orit Kaidar-Person¹⁰, Yvette van der Linden¹¹, Icro Meattini¹², Maximilian Niyazi¹³, Nick Reynaert¹⁴, Dirk de Ruysscher¹⁵, Stephanie Tanadini-Lang⁵, Peter Hoskin¹⁶, Philip Poortmans¹⁷, Carsten Nieder¹⁸

¹University Hospital of Zurich, Dept. of Radiation Oncology, Zurich, Switzerland; ²Paul Scherrer Institute , Center for Proton Therapy, Villigen, Switzerland; ³University of Leeds, Leeds Institute of Medical Research at St. James's, Leeds, United Kingdom; ⁴European Organisation for Research and Treatment of Cancer, Headquarters, Brussels, Belgium; ⁵University Hospital of Zurich, University of Zurich, Dept. of Radiation Oncology, Zurich, Switzerland; ⁶Cantonal Hospital of Graubünden, Institute of Radiation-Oncology, Chur, Switzerland; ⁷Catharina Hospital Eindhoven, Dept. of Radiation Oncology, Eindhoven, The Netherlands; ⁸Aarhus University Hospital, Danish Centre for Particle Therapy, Aarhus, Denmark; ⁹University Medical Center Groningen, Dept. of Radiation Oncology, Groningen, The Netherlands; ¹⁰Sheba Medical Center, Breast Cancer Radiation Therapy Unit, Ramat Gan, Israel; ¹¹University Medical Centre Leiden , Dept. of Radiation Oncology, Leiden, The Netherlands; ¹²Azienda Ospedaliero Universitaria Careggi, Radiation Oncology Unit, Oncology Department, Florence, Italy; ¹³University Hospital, LMU Munich, Dept. of Radiation Oncology, Munich, Germany; ¹⁴Institut Jules Bordet, Dept. of Medical Physics, Brussels, Belgium; ¹⁵Maastricht University Medical Centre, Dept. of Radiation Oncology Maastro, Maastricht, The Netherlands; ¹⁶University of Manchester, Mount Vernon Cancer Centre and Division of Cancer Sciences, Manchester, United Kingdom; ¹⁷Iridium Netwerk, University of Antwerp, Faculty of Medicine and Health Sciences, Department of Radiation Oncology , Wilrijk-Antwerp, Belgium; ¹⁸Nordland Hospital Trust, Department of Oncology and Palliative Medicine, Bodø, Norway

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Purpose or Objective

With the availability of new radiation techniques, image guidance and adapted fractionation schemes, the use of re-irradiation (re-RT) for different sites is increasing, although prospective evidence is still scarce and a standardized nomenclature is lacking. We hereby present the consensus definition of re-RT and recommendations to harmonize reporting for clinical studies, prepared in the scope of the EORTC RP-2011 ReCare study.

Material and Methods

This consensus was developed during the preparation of the prospective observational ReCare cohort within the ESTRO-EORTC E2-RADIatE project, aiming to gather real-world data on safety and efficacy of high-dose re-RT to derive evidence-based dose/fractionation settings for re-RT. The 17 panellists represent experts from different professional backgrounds (e.g., radiation oncologists, clinical oncologists, medical physicists) and have been selected based on their publication track record on re-RT. The consensus is based on a systematic review and an adapted Delphi process.

Results

Fourteen potential characteristics of re-RT were collated and grouped into categories (irradiated region, prescription dose, time interval between treatments and degree of overlap). We reached consensus on: 1) a new course of RT, 2) overlap of irradiated volumes, 3) toxicity concerns from cumulative doses. The following definition of re-RT was derived: “Re-RT is a new course of RT either to a previously irradiated volume (irrespective of concerns of toxicity) or where the cumulative dose raises concerns of toxicity”. To distinguish other forms of repetitive RT, two additional terms were introduced (Figure 1). Finally, a hierarchical question-based decision tree was built to help classify patients selected for repetitive RT (Figure 2).

Figure 1: Examples for scenarios of re-RT and re-treatments with RT.

Figure 2: Decision tree for the definition of re-RT and classification for scenarios with RT re-treatment. Q1: Is there a geometrical overlap of the irradiated volumes?; Q2: Is there a concern for toxicity from the cumulative doses?; Q3: Are the target volumes of current and previous RT located in the same organ?

The EORTC RP-2011 ReCare cohort will include patients with re-RT to a prescription dose or mean GTV dose of at least 50 Gy (EQD2). EBRT (photons, electrons, particles) and brachytherapy are allowed. The first phase (target accrual n=500) will include thoracic, abdominal and pelvic re-RT. Quality of life and treatment decision agreement will be evaluated as patient reported outcomes.

Conclusion

We propose a universally applicable consensus definition of re-RT and standardised nomenclature for scenarios of repetitive RT that do not fulfil the criteria for re-RT. This will foster harmonised reporting in clinical trials, with first clinical implementation in the EORTC RP-2011 ReCare cohort.