ESTRO 2024 - Abstract Book

S5504

RTT - Patient care, preparation, immobilisation and IGRT verification protocols

ESTRO 2024

should be offered an alternative where possible instead of treatment in FB. Further evaluation in a larger cohort including assessment of margins based on patient-specific factors is warranted.

Keywords: Respiratory motion, motion management.

References:

1. US National Institutes of Health. Clinical Trial NCT04748094: Quantification of Abdominal Organ Motion Using MRI (QUANTUM) [Internet]. [cited 2023 May 24]. Available from: https://clinicaltrials.gov/study/NCT04748094

2. US National Institutes of Health. Clinical Trial NCT02973828: Development of Daily Online Magnetic Resonance Imaging for Magnetic Resonance Image Guided Radiotherapy (PRIMER) [Internet]. Available from: https://clinicaltrials.gov/ct2/show/NCT02973828?term=NCT02973828&draw=2&rank=1

1034

Proffered Paper

A randomized prospective study comparing frameless immobilization systems for stereotactic brain-RT

Dylan Callens 1,2 , Lise Stessens 1 , Chahrazad Benazzouz 1 , An Nulens 1 , Wout Piot 1 , Maarten Lambrecht 1,2 , Patrick Berkovic 1,2 , Jean-François Daisne 1,2,3 1 University Hospitals Leuven, Department of Radiation Oncology, Leuven, Belgium. 2 KU Leuven, Laboratory of Experimental Radiotherapy, Leuven, Belgium. 3 Leuven Cancer Institute, LKI, Leuven, Belgium

Purpose/Objective:

In the context of stereotactic brain radiotherapy, it is crucial to limit patient movement while ensuring patient comfort. For this purpose, the Double Shell Encompass™ Fibreplast System (DS Encompass) by CQ Medical™ (formerly known as QFix) is frequently used for frameless immobilization. In our clinic, it is observed that the anterior shell exhibits a shrinkage after moulding, even when adhering to the prescribed mask-creation protocol. This occasionally complicates the process of closing the mask. To address this, an alternative mask model has been proposed by CQ Medical with the rear shell being replaced by a Moldcare® immobilization cushion (M Encompass) . To ascertain and validate the use of this method in conjunction with non-coplanar treatment modalities, we wanted to assess whether the moldcare solution is at least as good as the DS Encompass . We performed a prospective randomized study comparing the inter-and intrafractional variations and patient comfort between both masks.

Material/Methods:

The study protocol was reviewed and approved by the Ethical Committee of our university hospital. Sixty patients were enrolled after providing written consent. After stratification by treatment regimen (radiosurgery, fractionated