ESTRO 2024 - Abstract Book

S4007

Physics - Inter-fraction motion management and offline adaptive radiotherapy

ESTRO 2024

results using a judicious ITV approach. Further research will focus on modelling the clinician-derived method and making it widely available for use.

Keywords: Cervix Cancer, plan of the day, online adaptive

References:

[1] Wang L, Alexander S, Mason S, et al. Carpe Diem: Making the Most of Plan-of-the-Day for Cervical Cancer Radiation Therapy. Pract Radiat Oncol 2023;13(2):132-147. DOI: 10.1016/j.prro.2022.11.005.

[2] The EMBRACE II investigators. Image guided intensity modulated External beam radiochemotherapy and MRI based adaptive BRAchytherapy in locally advanced CErvical cancer (EMBRACE-II).

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Digital Poster

Continuous positive airway pressure as a method of diaphragmal motion management in SBRT

Justus Kaufmann 1 , Johanna Schaeben 1 , Heiko Karle 1 , Laura Oebel 1 , Arnulf Mayer 2,1 , Tilman Bostel 1,3 , Heinz Schmidberger 1 , Marcus Stockinger 1 1 University Medical Center Mainz, Department of Radiation Oncology, Mainz, Germany. 2 Peter MacCallum Cancer Centre, Department of Radiation Oncology, Melbourne, Australia. 3 Radiological Institute Dr. von Essen, Department of Radiation Oncology, Koblenz, Germany

Purpose/Objective:

There is large inter-institutional variety in diaphragmal motion management for SBRT of the lung or upper abdomen. Methods range from irradiation in deep inspiration breath holding (DIBH) to abdominal compression with a multitude of compression devices. Especially abdominal compression techniques come with significant deformation of upper abdominal anatomy, complicating matching of diagnostic and therapeutic imaging during treatment planning. Aim of this pilot study was to assess the feasibility and efficacy of non-invasive ventilation with continuous positive airway pressure (CPAP) as another method of motion management for patients receiving SBRT in our department.

Material/Methods:

12 patients with a total of 17 target lesions received a 4D planning CT scan with CPAP ventilation with a positive end expiratory pressure (PEEP) of up to 15 mbar (Figure 1). In addition, 3 patients received an additional planning CT scan either with another form of motion management or in free breathing (FB). Most lesions were located in the lung (n = 6), liver (n = 5) or adrenal gland (n = 4). Patients were treated during CPAP ventilation using the same PEEP as during the planning CT scan. Radiotherapy treatment was delivered with 3 to 5 fractions. In all upper abdominal SBRT targets