ESTRO38 Congress Report

RTT

3. MeRInO study: Defining a standardised delineation method for repeated GTV assessment using DW MRI Aileen Duffton 1 , Ian McCrea 2 , Sarah Allwood-Spiers 3 , Lisa Hay 4 , Lynsey Devlin 4 , Marimuthu Sankaralingam 3 , Maureen Thomson 4 , Philip McLoone 5 , Mark McJury 3 , John Foster 3 , Claire Paterson 6 .

Beatson West of Scotland Cancer Centre, Glasgow, UK

Context of the study Radiotherapy is an effective treatment for head and neck cancer. Although this is the case, there are still patients who do not respond well to treatment and will relapse. Although intensified treatment may be beneficial to non-responders, we cannot predict these patients early enough to adapt their treatment. Because high doses of radiotherapy can cause side effects, it is not desirable to escalate the dose to all patients. The overall aimof theMeRInO study is to determine whether repeated diffusion weighted MR images (dwMRI) can be used to predict the non-responders. This could allow an adaptive intensified treatment to be delivered, only to those who require it. Overview of abstract The purpose of this abstract is to standardise howwe define disease on dwMRI for the first 20 patients recruited and consented toMeRInO study. As the study will be measuring disease on images before treatment, and repeat images two weeks into treatment, a standardised approach is required. Although evidence shows the potential of this type of imaging, it often doesn’t describe how these volumes are defined. We describe the steps taken to ensure changes are assessed in a reliable way and to quantify any treatment induced changes. Here, we report the change in disease volume for 20 patients. Future evaluations of will include additional biological information, for the total of 80 patients.

What were the three main findings of your research? Here we show it was feasible to define volumes on repeated images using methods we describe for most patients (18/20). The volume change has been quantified on the images, showing that target volumes decrease by around 45% after two weeks of radiotherapy. Further work will quantify biological changes on these images. What impact could your research have? Outcomes from theMeRInO study will provide a key piece of evidence, assessing whether dwMRI can be used to predict a response in patients with oropharyngeal cancer. This piece of work describes the standardisedmethods that will be used for all patients, aiming to have a final recruitment number of 80 participants. If results demonstrate images can be used to predict outcomes from chemo-radiotherapy during treatment, then individualised, and adaptive treatment strategies may be employed within future studies. This has potential to increase the number of patients we cure. Is this research indicative of a bigger trend in oncology? There is growing evidence to demonstrate the value of functional imaging in predicting a response for cancer of the oropharynx. High quality studies are essential to inform future clinical trials of adaptive radiotherapy.

Congress report | RTT

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