ESTRO 2023 - Abstract Book

S544

Sunday 14 May 2023

ESTRO 2023

Conclusion Reirradiation of RM progressing after previous RT appears to be feasible with promising clinical outcomes and an acceptable toxicity profile. Prognostic factors in the decision-making process have been identified and should be incorporated in daily practice

PD-0653 Target volume delineation for radiotherapy of meningiomas: an ANOCEF consensus guideline.

N. MARTZ 1 , J. Salleron 2 , F. Dhermain 3 , G. Vogin 4 , J. Daisne 5 , R. Mouttet-Audouard 6 , R. Tanguy 7 , G. Noel 8 , M. Peyre 9 , I. Lecouillard 10 , J. Jacob 11 , J. Attal 12 , M. Charissoux 13 , O. Veresezan 14 , C. Hanzen 14 , A. Huchet 15 , I. Latorzeff 16 , A. Coutte 17 , J. Doyen 18 , D. Stefan 19 , L. Feuvret 11 , G.C. Garcia 20 , P. Royer 1 1 Institut de Cancérologie de Lorraine, Radiotherapy, Vandoeuvre-Les-Nancy, France; 2 Institut de Cancérologie de Lorraine, Cellule Data-biostatistique, Vandoeuvre-Les-Nancy, France; 3 Gustave Roussy University Hospital, Radiotherapy, Villejuif, France; 4 Centre Francois Baclesse, Radiotherapy, Luxembourg, Luxembourg; 5 Leuven Cancer Institute, Radiotherapy, Leuven, Belgium; 6 Oscar Lambret Comprehensive Cancer Centre, Radiotherapy, Lille, France; 7 Léon Bérard Cancer Centre, Radiotherapy, Lyon, France; 8 Paul Strauss Cancer Centre, Radiotherapy, Strasbourg, France; 9 Groupe Hospitalier Pitié Salpêtrière, Neurosurgery, Paris, France; 10 Eugène Marquis Cancer Centre, Radiotherapy, Rennes, France; 11 Hôpital Pitié Salpêtrière Charles Foix, Radiotherapy, Paris, France; 12 Institut Claudius Regaud, Radiotherapy, Toulouse, France; 13 Centre Val d’Aurelle, Radiotherapy, Montpellier, France; 14 Cancer Centre Henri Becquerel, Radiotherapy, Rouen, France; 15 Centre Hospitalier et Universitaire de Bordeaux, Radiotherapy, Bordeaux, France; 16 Groupe ONCORAD Garonne and Clinique Pasteur, Radiotherapy, Toulouse, France; 17 Centre Hospitalier Universitaire d’Amiens, Radiotherapy, Amiens, France; 18 Antoine Lacassagne Cancer Center, Radiotherapy, Nice, France; 19 François Baclesse Cancer Centre, Radiotherapy, Rennes, France; 20 Gustave Roussy University Hospital, Diagnostic Radiology, Villejuif, France Purpose or Objective Meningiomas are the most common primary intracranial tumor. They are developed at the expense of the arachnoid, with an overall incidence which has increased over the past decade. To date, there is no published specific guideline about meningiomas target volume. No prospective study has defined a consensus for delineation in meningiomas’ radiotherapy. Therefore, target volume definition is mainly based on retrospective studies, with a heterogeneous population of patients. The aim of this paper is to describe delineation guidelines for meningiomas’ radiotherapy as an adjuvant or definitive treatment with Intensity Modulated Radiation Therapy (IMRT) and stereotactic radiation therapy (SRT) techniques. Materials and Methods This guideline is based on a consensus endorsed by a global multidisciplinary group of brain tumor experts’ member of the ANOCEF (French neuro-oncology association). A two round modified Delphi consensus was achieved, and the consensus was adopted by the RAND/UCLA method. The third round was carried out in videoconference, in order to allow experts to debate and argue on remaining uncertain proposals. Results Twenty experts from 17 radiotherapy center participated. After 3 rounds, all the proposals resulted in a consensus. The ANOCEF guideline committee proposed to perform an unenhanced planning CT scan, merged with a post-contrast MRI obtained at the time of radiotherapy and preoperative MRI in case of adjuvant treatment.