EMBRACE Studies and EMBRACE Research

The GEC ESTRO gyn network has designed and initiated the EMBRACE studies which develop, perform and evaluate image guided radiotherapy in cervix cancer with a special focus on improving clinical outcome. The original focus of EMBRACE studies was MRI based adaptive brachytherapy (EMBRACE I). The scope was then widened to include also image guided radiotherapy and systemic treatment, at present in the form of concomitant radiochemotherapy (EMBRACE II). The EMBRACE study office was located within the department of radiotherapy, Comprehensive Cancer Center, Vienna General Hospital, Vienna Medical University.

The international EMBRACE I study was initiated in 2008 with the aim of evaluating and benchmarking image guided brachytherapy in a prospective multicentre study (see link to EMBRACE I). This first prospective study was based on the pioneering technical and clinical experience of some European institutions in this field and the concepts of the Gyn GEC ESTRO working group, in particular on target volume delineation, dose volume reporting and the use of the linear-quadratic model. There were no dose prescription constraints, neither for the residual tumor and the adaptive target volume, nor for organs at risk. Dose prescription for brachytherapy had to follow institutional guidelines. Intracavitary and combined interstitial/intracavitary techniques were allowed for. There was a prescription protocol for external pelvic beam radiotherapy and radiochemotherapy. Overall treatment time was restricted to 50 days. Accrual was finalized end of 2015 with overall 1416 patients.

The RetroEMBRACE study was initiated in parallel to the EMBRACE I study. A retrospective data collection was carried out in 12 institutions that had built up clinical experience before the EMBRACE I study, applying the Gyn GEC ESTRO Recommendations for target delineation and dose volume reporting (see link to RetroEMBRACE). The retrospective data collection (CRF) was analogue to that of what was implemented for EMBRACE I. Accrual was finalized in 2013 with overall 814 patients.

A prospective substudy on vaginal morbidity was initiated during EMBRACE I and addresses in particular issues of vaginal morbidity (see link to Vaginal Morbidity and Sexuality). The vaginal substudy comprises a limited patient cohort of some dedicated centers following a specific study protocol on the assessment of vaginal morbidity within EMBRACE I.

The EMBRACE II study (see link to EMBRACE II) defines a number of interventions which address local, nodal and systemic treatment as well as exposure of organs at risk. EMBRACE II prescribes MRI guided adaptive brachytherapy with combined intracavitary/interstitial techniques and specific dose volume constraints for adaptive targets and OARs and image guided external beam radiotherapy for specific targets and techniques (IMRT, IGRT, SIB for nodal disease) and concomitant radiochemotherapy. EMBRACE II was initiated in 4/2016.

A study on vaginal cancer is planned to start in 2018 (EMBRACE I Vagina) in parallel with the projected publication of the Gyn GEC ESTRO recommendations on vaginal cancer target delineation through the vaginal task force of the GEC ESTRO gyn network.

The EMBRACE research group is responsible for the clinical research structure linked to the EMBRACE studies and was implemented in 2011. Currently >20 studies are published (link to EMBRACE publications) or are in progress (link to “projects” and “manuscripts under submission”) addressing questions such as local, nodal and systemic recurrences; bladder, rectal, bowel, and vaginal morbidity; patient reported outcome and QoL (link to QoL); prognostic and predictive parameters; physics parameters, 3D QA etc. and the findings from the vaginal substudy.

Two new EMBRACE research fields were initiated during 2016 related to the EMBRACE clinical database. “Functional imaging”, linking imaging data to clinical outcome with a retrospective and prospective part (link to Functional MRI); “Translational Research” (Molecular biomarkers), linking patterns of biomarker expression to clinical outcome with a retrospective and prospective part (link to translational research).