Implementing EMBRACE II – The Liverpool Experience
BACKGROUND AND PURPOSE The Image guided intensity modulated External beam radiochemotherapy and MRI based adaptive BRAchytherapy in locally advanced CErvical cancer (EMBRACE-II) trial is an international, interventional, prospective, multi-centre study which aims at benchmarking local control, nodal control, systemic control and overall survival, as well as treatment related morbidity and quality of life, in patients with locally advanced cervix cancer. We describe the changes required to our practice at Liverpool Hospital to implement the EMBRACE-II protocol. METHODS All EMBRACE-II patients undergo a staging PET and pelvic MRI. Planning CT, PET & MRI are used to generate planning target volumes. External beam radiotherapy (EBRT) (45Gy/25#; IMRT or VMAT) incorporates simultaneous integrated boost (SIB) for positive pelvic (55Gy/25#) and para-aortic lymph nodes (57.5Gy/25#). Concurrent cisplatin (40mg/m2) is given weekly (at least 5 cycles). There is no mandated brachytherapy schedule, but cumulative EQD210 dose to high risk clinical target volume (HRCTV) ideally 90-94Gy (EBRT + brachytherapy) with overall treatment time (OTT) of 50 days. Follow-up for 5years, PET at 3mths post-treatment, MRI at 3 & 12mths post-treatment. RESULTS While VMAT, concurrent cisplatin chemotherapy and image-guided adaptive MR brachytherapy is standard of care at our institution, there were a number of aspects where EMBRACE-II differed from our usual practice. These differences included: Contouring: Naming convention; ITV/PTV margins; Elective nodal volumes Planning: Protocol sparse in terms of planning aims for EBRT; Cooler plans with regards to PTV/CTV coverage and conformity index; Stricter OAR dose constraints Brachytherapy: OAR constraints tighter (rectum, bladder, sigmoid); Contouring IRCTV; New reporting structures (eg PIBS) Scheduling: Changed to 4# brachytherapy (7.75Gy/#), weekly starting in week 4 of EBRT from 3# starting week 5 to fulfill OTT of 50 days while achieving HRCTV D90 of 90Gy without exceeding OAR constraints; Interstitial needles more complicated to plan therefore unable to treat 2 patients in one day. Post-treatment imaging: PET & MRI post-treatment not routine practice unless clinical suspicion of persistent/recurrent disease. CONCLUSIONS The EMBRACE-II trial builds upon the findings of retro-EMBRACE to provide updated brachytherapy target and DVH aims. The EMBRACE-II trial protocol has been successfully implemented at Liverpool Hospital. It has allowed us to move forward with treatment for our cervix cancer patients in a protocoled manner under the aegis of an international trial.
Liverpool Cancer Therapy Centre, Liverpool Hospital, Sydney, Australia
Dr Karen Lim is a radiation oncologist at Liverpool Hospital. Her tumour sites are Gynae & Breast. She has an interest in MR-guided radiotherapy.