ESTRO 2023 - Abstract Book

S839

Tuesday 16 May 2023

ESTRO 2023

We will present the wealth of data suggesting better outcomes after SBRT in the treatment of metastatic disease, including biological, observational and randomised data. We will explain why it is good for the radiotherapy community to embrace change and be ready to move the field forward.

SP-1007 Against the motion T. Zilli The Netherlands

Abstract not available

Symposium: How to introduce innovations in risk stratification to clinical management of gynaecological cancers

SP-1011 Risk stratification in endometrial cancer: Evidence, future steps, and how to implement in everyday clinic C. Creutzberg The Netherlands

Abstract not available

SP-1012 Risk stratification for cervical cancer: Circulating HPV DNA - Evidence and road to implementation K. Han 1 1 Princess Margaret Cancer Centre, Radiation Oncology, Toronto, Canada Abstract Text Despite advances in MRI-guided brachytherapy, a significant portion of patients with locally advanced cervical cancer relapse after definitive chemoradiation. Known clinical prognostic factors, such as stage and nodal status, are poor predictors of relapse (concordance index approximately 0.62). Adjuvant therapies may benefit a subset of patients, but clinical trials have been hampered by the lack of accurate biomarkers to identify early those patients at highest risk of relapse. Tumors continually shed DNA into the circulation, where they can be accessed noninvasively and can provide a means for measurement of disease burden. The majority of cervical cancer is caused by HPV. HPV DNA provides a unique marker that distinguishes tumor-derived DNA from normal, nonmalignant sources of cell-free DNA (cfDNA). Digital polymerase chain reaction (dPCR) is an ultrasensitive and affordable technique for absolute quantification of cfDNA. Next generation sequencing (NGS) has emerged in recent years as a promising alternative methodology for detection of tumour-derived cfDNA (ctDNA). This session will review the evidence for HPV ctDNA in cervical cancer, new HPV ctDNA detection technologies, knowledge gaps and road to clinical implementation. SP-1013 Risk stratification for cervical cancer: Hypoxia profiles from gene expression to imaging, evidence and road to implementation K. Bruheim

Abstract not available

Symposium: Reducing the target volumes in external beam therapy

SP-1014 Treatment margins in the era of MR-linacs, tracking and adaptive planning - Will zero millimetre CTV-PTV margin ever be feasible? M. van Herk

Abstract not available

SP-1015 Keeping local control high with smaller target volumes E. Troost 1 1 Faculty of Medicine and University Hospital Carl Gustav Carus, Radiotherapy and Radiation Oncology, Dresden, Germany Abstract Text The excellent local control rates achieved by radiotherapy ought not to be jeopardised by ever decreasing target volumes in the era of image-guided adaptive radiotherapy. Having said this, there is evidence of excellent local control rates, e.g., when applying SABR or brachytherapy. Therefore, this presentation will briefly discuss the challenges currently faced and more importantly present publications as well as clinical standards for modified margin recipe concepts leading to reduced target volumes.

SP-1016 The PTV concept should be replaced with robust optimisation in EBRT M. Witte The Netherlands

Abstract not available

Symposium: Proton arc therapy: Status and potential