ESTRO 2022 - Abstract Book

S408

Abstract book

ESTRO 2022

Results The automatic GTV overlapped with the clinical (true positive) by overall median 90% (range=33-100%) (p < 0.005), with a mean size=43% compared to the clinical GTVs. Median Dice coefficient=65% (range=15-77%) (p < 0.005). The automatic CTV-segments overlapped with the clinical (true positive result) by median=98% (range=93-100%), mean size=56% compared to the clinical CTV. Median Dice coefficient=59% (range 15-77%) (p < 0.05).

The recurrent GBM overlapped with the primary clinical CTV by median 0% true positive (range=0-79%), and median 0% Dice coefficient (range 0-13%) (p < 0, 5).

Conclusion We found a high degree of overlap in detecting the spatial area of malignant tissue using HD-GLIO, demonstrating the method feasible to employ as a support tool for oncologists. Based on these findings, we have initialized a more extensive study. We found a low degree of overlap between CTV-margin and recurrent tumor. This could suggest radiation treatment response, but considering the known tumor radioresistance it could also mean that irradiating this large margin of potentially normal tissue cells was only contributing to side effects. We suggest more research is performed to investigate recurrence patterns in relation to irradiated tissue volumes on this patient group. D. Azria 1 , L. Boldrini 2 , M. De Ridder 3 , P. Fenoglietto 1 , M.A. Gambacorta 2 , T. Gevaert 3 , G. Gungor 4 , F.J. Lagerwaard 5 , A.E. Marciscano 6 , M. Michalet 1 , H. Nagar 6 , R. Pennell 6 , I. Serbez 7 , B. Vanspeybroeck 3 , T. Zoto Mustafayev 7 , A. Caffaro 8 , L. Hardy 8 , S. Kandiban 8 , A. Oumani 9 , T. Roque 10 , N. Paragios 8 , K. Shreshtha 11 , E. Ozyar 7 1 L'Institut du Cancer de Montpellier, Department of Radiation Oncology, Montpellier , France; 2 Fondazione Policlinico Universitario A. Gemelli IRCCS, Radiation Oncology, Rome, Italy; 3 UZ Brussel, Vrije Universiteit Brussel, Radiotherapy Department, Brussels, Belgium; 4 Acibadem MAA University, Maslak Hospital, Radiation Oncology, Istanbul, Turkey; 5 Amsterdam UMC, Dept. of Radiation Oncology, Amsterdam, The Netherlands; 6 NewYork-Presbyterian/Weill Cornell Hospital, Radiation Oncology, New York, USA; 7 Acibadem MAA University, Maslak Hospital, Radiation Oncology, Istanbul, Turkey; 8 TheraPanacea, Research and Development, Paris, France; 9 TheraPanacea, AI Department, Paris, France; 10 TheraPanacea, Clinical and Partnerships Affairs, Paris, France; 11 TheraPanacea, AI Research Department, Paris, France Purpose or Objective MRgRT treatment online planning and adaptation offers new perspectives for pelvic and abdominal radiation treatment (RT). It is associated with better soft tissue visualization, functional information about tumor proliferation, adaptation without additional toxicity at each RT fraction while enabling online target volume tracking capabilities. However, MR- Linac throughput is unfavorably compared with conventional RT delivery devices (factor of 3) since treatment adaptation OC-0463 AI surpassing human expert: a multi-centric evaluation for organ at risk delineation