ESTRO 2024 - Abstract Book

S1038

Clinical - Gynaecology

ESTRO 2024

Based on our results, aRT, with or without concurrent chemotherapy, has a relevant role in the treatment of patients with vulvar cancer. The OTT may play a critical role in determining clinical outcomes.

Keywords: vulvar cancer, radiochemotherapy

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Digital Poster

MARGARITA: MRLinac Boost for Gynecological Cancers if brachytherapy is not feasible. Initial results

Astrid van Lier 1 , Uffe Bernchou 2,3 , Femke van der Leij 1 , Anja Ør Knudsen 4 , Jochem Hes 1 , Gitte-Bettina Nyvang 4 , Ronald Zweemer 5 , Eline Groot - van Breugel 1 , Irene Hazell 2 , Tine Schytte 3,4 , Anders Smedegaar Bertelsen 2 , Ina Jürgenliemk-Schulz 1 1 UMC Utrecht, Department of Radiotherapy, Utrecht, Netherlands. 2 Odense University Hospital, Laboratory of Radiation Physics, Department of Oncology, Odense, Denmark. 3 University of Southern Denmark, Department of Clinical Research, Odense, Denmark. 4 Odense University Hospital, Department of Oncology, Odense, Denmark. 5 UMC Utrecht, Department of Gynaecological Oncology, Utrecht, Netherlands

Purpose/Objective:

To report the design of the MARGARITA study (NCT05937958) and its clinical feasibility in a multi-center setting. The MARGARITA study aims to collect dosimetric, clinical and patient reported outcomes data of patients with gynecological cancer treated on a 1.5T MRLinac (MRL, Unity, Elekta AB) to boost the GTV and the high-risk CTV (CTV-HR) in case a brachytherapy (BT) boost was not feasible.

Material/Methods:

MARGARITA was initiated by our multi-center group because not all patients with gynecological tumors that qualify for BT after external beam (chemo)radiotherapy can receive BT, e.g. due to contraindications associated to anesthesia or hospitalization, tumor size and shape, and the patient’s preference. Considering that 1) high dose levels are needed to achieve local control, 2) radiosensitive structures (e.g. bladder, rectum, bowel) are near the target, 3) targets and OARs are mobile and deformable between and during treatment fractions, and 4) targets