ESTRO 2023 - Abstract Book

S1457

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ESTRO 2023

QUARTET is a SIOPE-EORTC collaborative project for radiotherapy quality assurance (RTQA) in paediatric clinical trials. Each participating centre must undergo site RTQA approval procedures, which are streamlined across all EORTC and QUARTET trials. The process includes a Facility Questionnaire (FQ) containing multiple choice and open-ended questions detailing site infrastructure, personnel, workload, radiotherapy techniques and RTQA methods used, as well as paediatric specific facilities. The aim of this work was to evaluate the profiles of radiotherapy centres participating in QUARTET RTQA. Materials and Methods We performed a descriptive analysis of the data collected via the QUARTET FQs. Sites that were approved for patient enrolment in EPSSG-FaR-RMS (EUDRACT 2018-000515-24), SIOPEN-VERITAS (EUDRACT 2015-003130-27) SIOPEN-HRNBL2 (EUDRACT 001068-31), SIOP-HRMB (EUDRACT 2018-004250-17) trials between October 2020- August 2022 were included. Results Currently 62 centres from 20 countries are approved to participate in QUARTET trials. Most sites are in the UK (16), France (10) and Australia (7). There are 55 photon, 4 proton, and 3 dual modality sites. The median no. of treatment units is 6/centre (range 3-16), and for proton centres a median of 3 treatment rooms (range 2-5). Molecular radiotherapy and brachytherapy are available in 12 and 19 centres, respectively. The majority (93%) are paediatric referral centres: 21 national, 32 regional and 5 international, with 46 centres having designated paediatric radiation oncologists. Table 1 shows the workload and human resources for approved sites. Paediatric MDTs take place in 49 sites, with 40 having access to resources for advice on unusual or rare cases. All centres use advanced techniques (IMRT/VMAT), and all proton centres have pencil beam scanning and IMPT. Deep sedation/general anaesthesia facilities are present in 55 sites. Forty-nine sites have paediatric-adapted protocols for CT simulation and 36 for MRI scanning. Table 1 Minimum Median Maximum Total no. of patients /year 350 2700 10200 Paediatric patients/year 0 36 272 Radiation Oncologists/centre (FTE) 3 15 63 Designated Paediatric Radiation Oncologists (FTE) 0 1.65 13.5 FTE= full-time equivalent

Figure 1. Map of centres participating in QUARTET

Conclusion This early data shows high variability in terms of workload and human and technical resources among sites participating in QUARTET-affiliated paediatric radiotherapy clinical trials. Most participants are reference centres for paediatric radiotherapy with the majority having paediatric-specific facilities such as designated clinicians, paediatric MDTs, and adapted imaging protocols. This is the first report from the QUARTET project, and we expect more mature data as trial recruitment increases and new trials open.

PO-1738 Hypofractionation with nodal SIB in cervical cancers: dummy run for the HYACINCT trial

W. Bacorro 1,2,3 , S.M. Cabrera 1 , M. Bojador 1 , M. Dumago 1 , K. Baldivia 1 , T. Sy Ortin 1,4