ESTRO 38 Abstract book

S433 ESTRO 38

of Medical Education and Research, Department of Radiotherapy and Oncology, Chandigarh, India ; 11 St James’s University Hospital, Leeds Cancer Centre, Leeds, United Kingdom ; 12 Radiotherapy Group, Radiation Oncology Department, Arnhem, The Netherlands ; 13 University Hospitals Leuven, Department of Radiation Oncology, Leuven, Belgium ; 14 Amsterdam University Medical Centers- University of Amsterdam, Department of Radiotherapy, Amsterdam, The Netherlands ; 15 St. Olavs Hospital, Clinic of Oncology and Women's Clinic, Trondheim, Norway ; 16 Cambridge University Hospitals NHS Foundation Trust- Addenbrooke's Hospital, Oncology Centre, Cambridge, United Kingdom ; 17 Leiden University Medical Center, Department of Radiation Oncology, Leiden, The Netherlands Purpose or Objective To evaluate differences in local stage by using the FIGO system (only gyn examination, ± endoscopy) compared to the T(NM) system based only on MRI in pats. with locally advanced cervical cancer treated with primary CCRT and MR-based IGABT within the EMBRACE study and to assess the uncertainties of FIGO staging next to available MRI. Material and Methods All 1416 pats. from EMBRACE I based on data dump (08/2017) were considered for analysis. Pats. were examined through gyn exam and MRI before treatment. Recto- and/or cystoscopy were optional. Tumour width, height and thickness in millimeter, infiltration of vagina, left and/or right parametrial tissue, pelvic wall, and rectum and/or bladder were reported as assessed through gyn exam ± endoscopy only and based on MRI only. For each pat. independent re-staging was performed through the investigators based on the database: (1) local FIGO stage (FIGO Cancer Report 2012/2015) based on clinical findings only; (2) T-stage (8 th edition, 2017) on MRI only. Descriptive statistics were used to sum up FIGO- and T- stages and cross tables to evaluate the differences in local Data was available from 1338 pats.: FIGO stage was IB in 264 (19.7%) pats., IIA in 83 (6.2%), IIB in 755 (56.4%), IIIA in 15 (1.1%), IIIB in 191 (14.3%), and IVA in 30 (2.2%). T- stage was T1b in 207 (15.5%) pats., T2a in 75 (5.6%), T2b in 834 (62.3%), T3a in 12 (0.9%), T3b in 125 (9,3%) and T4a in 85 (6.4%) (table 1). Differences in local tumour staging were found in overall 388 pats. (28.9%) (table 1): 141 pats. (10.5%) had a lower T-stage compared to FIGO, whereas 247 pats. (18.5%) had a higher T-stage. In FIGO IIB, 95/755 (12.5%) had a change in T-stage, ranging from T1b1 to T4a. In overall FIGO IB, 128/264 (48.5%) changed to another T-stage. For FIGO IB1, change of stage was in 50.4%, to T1b2 and T2b. For FIGO IB2, change was in 46.3%, mainly to T2b. For FIGO IIA (n=83), change of T-stage was in 66% (T2a1 to T2a2; and to T2b). For FIGO IIIB change of stage was in 100/191 (52.4%) with 62 classified as T2b and 35 as T4a. The small group of FIGO IVA pats. (n=30) changed in 13.3% to another T-stage (T2b/T3b). Change of stage between FIGO and T- stage varies considerably between the different FIGO stages from min 12.5% in FIGO IIB to max 69.2% in FIGO IIA1. FIGO staging as performed primarily through the centers was different from FIGO re-staging through the investigators in 154/1338 pats. (11.5%). staging. Results

PO-0827 Comparison of clinical examination and MRI for local cervical cancer staging (FIGO and T(NM)) J. Knoth 1 , R. Pötter 1 , I. Jürgenliemk-Schulz 2 , C. Haie- Meder 3 , L. Fokdal 4 , A. Sturdza 1 , P. Hoskin 5 , U. Mahantshetty 6 , B. Segedin 7 , K. Bruheim 8 , E. Wiebe 9 , B. Rai 10 , R. Cooper 11 , E. Van der Steen-Banasik 12 , E. Van Limbergen 13 , B. Pieters 14 , M. Sundset 15 , L.T. Tan 16 , R. Nout 17 , K. Tanderup 4 , C. Kirisits 1 , N. Nesvacil 1 , J.C. Lindegaard 4 , M. Schmid 1 1 Medical University Vienna, Department of Radiation Oncology, Wien, Austria ; 2 University Medical Centre Utrecht, Department of Radiotherapy, Utrecht, The Netherlands ; 3 Institut Gustave-Roussy, Department of Radiotherapy, Paris, France ; 4 Aarhus University Hospital, Department of Oncology, Aarhus, Denmark ; 5 Mount Vernon Cancer Centre, Department of Radiotherapy, Northwood, United Kingdom ; 6 Tata Memorial Hospital, Department of Radiation Oncology, Mumbai, India ; 7 Institute of Oncology Ljubljana, Department of Oncology, Ljubljana, Slovenia ; 8 The Norwegian Radium Hospital- Oslo University Hospital, Department of Oncology, Oslo, Norway ; 9 Cross Cancer Institute and University of Alberta, Department of Oncology, Edmonton, Canada ; 10 Postgraduate Institute