Abstract Book

S202

ESTRO 37

OC-0393 Validating tumour extension by MRI with histoPAthology in cervical cancer; the MPAC- study P. De Boer 1 , M.C.G. Bleeker 2 , A.J.A.J. Van de Schoot 3 , M.R. Buist 4 , G. Kenter 4 , J. Stoker 5 , A.M. Spijkerboer 5 , A. Nederveen 5 , S. Bipat 5 , M.J. Van de Vijver 2 , C.R.N. Rasch 1 , L.J.A. Stalpers 1 1 Academic Medical Center, Radiation Oncolo gy, Amsterdam, The Netherlands 2 Academic Medical Center, Pathology, Amsterdam, The Netherlands 3 Netherlands Cancer Institute - Antoni van Leeuwenhoek, Radiation Oncology, Amsterdam, The Netherlands 4 Academic Medical Center, Gynaecology, Amsterdam, The Netherlands 5 Academic Medical Center, Radiology, Amsterdam, The Netherlands OC-0394 Pretreatment bone marrow SUVmax in locally advanced cervical cancer: a novel prognostic biomarker ? R.D. Seban 1 , C. Robert 2 , L. Dercle 3 , R. Yeh 3 , S. Reuze 4 , A. Schernberg 2 , J. Lumbroso 1 , M. Schlumberger 1 , C. Haie- Meder 2 , C. Chargari 2 , E. Deutsch 2 1 Institut Gustave Roussy, Nuclear Medicine and Endocrine Oncology, Villejuif, France 2 Institut Gustave Roussy, Radiotherapy, Villejuif, France 3 Columbia University Medical Center, Radiology, New- York, USA 4 Institut Gustave Roussy, Medical Physics, Villejuif, France Purpose or Objective We investigated the prognostic value of pretreatment Bone Marrow maximum standardized uptake value (BM SUVmax) at baseline on 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in patients with locally advanced cervical cancer. Material and Methods We recruited retrospectively patients with locally advanced cervical cancer who underwent staging 18F-FDG PET/CT and had baseline blood tests then treated by chemoradiation therapy (CRT), followed by image-guided adaptive brachytherapy (IGABT). Bone marrow and tumor maximum standardized uptake value (BM and tumor SUVmax) were calculated using a manual segmentation method. Neutrophilia was defined as a count over 7 x10 9 /L at the time of diagnosis. Prognostic value of BM SUVmax, tumor SUVmax and neutrophilia for predicting locoregional recurrence-free survival (LRFS) and overall survival (OS) was assessed using a Cox hazard regression analysis. Cut-off values for imaging biomarkers were obtained from receiver operating characteristic (ROC) curves and DeLong tests were used to test the statistical significance of the differences between the areas under ROC curves. Results One-hundred and seventeen patients with FIGO stage Ib1- IVb cervical cancer, treated between 2005 and 2014, were included. The median follow-up was 41.6 months (range 5.0-100.4). BM SUVmax, tumor SUVmax and neutrophilia were significant univariate prognostic factors for poorer locoregional failure-free survival (p<.001; p =.002 and p=.005 respectively) and poorer overall survival (p<.001; p =.003 and p<.001 respectively). Cut off values maximizing the sum of sensitivity and specificity but also accuracy for LRFS were 2.8 for BM SUVmax (AUC 0.76, accuracy 0.74) and 15.2 for tumor SUVmax (AUC 0.66, accuracy 0.69).Comparing the AUC with the DeLong method, BM SUVmax tended to predict locoregional recurrence better than tumor SUVmax did, although the difference was not statistically significant (p=0.112), despite a consequent gap between AUCs (0.096). In Abstract withdrawn

multivariate analysis, LRFS and OS were significantly poorer in patients with high BM SUVmax, defined as over 2.8, compared to those with lower BM SUVmax (respectively p < .001; HR 4.3; CI 95 % [1.8-9.9] and p = .001; HR 4.3; CI 95 % [1.9-9.8]). Neutrophilia remained an independent statistically significant prognostic factor for LRFS (HR 2.0, p=0.033) and for OS (HR 2.4, p=.009). Conclusion Pretreatment BM SUVmax on 18F-FDG PET is a significant prognostic factor for LRFS and OS in locally advanced cervical cancer treated with CRT plus IGABT. Strikingly, baseline BM SUVmax tended to be a better predictor of locoregional recurrence than tumor SUVmax. This PET biomarker could help identifying patients with higher risk of locoregional recurrence beyond tumor staging. OC-0395 The significance of elevated SCC-Ag in squamous-cell carcinoma of uterine cervix with chemoradiation K.H. Choi 1 , S.W. Lee 1 , Y.S. Kim 1 , M. Yu 2 , S. Jeong 3 , S. Sung 4 , J.H. Lee 4 1 Seoul St. Mary's Hospital, Department of Radiation Oncology, Seoul, Korea Republic of 2 Bucheon St. Mary's Hospital, Department of Radiation Oncology, Bucheon, Korea Republic of 3 Ewha Woman's University School of Medicine, Department of Radiation Oncology, Seoul, Korea Republic of 4 St. Vincent's Hospital, Department of Radiation Oncology, Suwon, Korea Republic of Purpose or Objective Most studies in cervical cancer have set the level of Scc- Ag (squamous-cell carcinoma antigen) over 1.5-2.5 ng/mL as a significant one for poor prognosis. However, there is no definitive guideline for the significance and cut-off value for Scc-Ag in cervical cancer. Thus, we attempt to analyze the optimal cut-off value for predicting tumor recurrence and patient survival in squamous-cell carcinoma of uterine cervix. Material and Methods From January 2004 to December 2016, we enrolled cervical cancer patients staging FIGO Ib-IVa who were diagnosed as squamous-cell carcinoma and received concurrent chemoradiation and intra-cavitary radiotherapy as a radical aim in multi-institution. All patients underwent pelvic MRI and evaluated Scc-Ag before radiotherapy. The cut-off value for Scc-Ag was calculated using the Receiver Operating Characteristic curve (ROC), and the comparison for recurrence-free survival (RFS) and overall survival (OS) was performed using Kaplan-Meier method. Results A total of 309 patients were enrolled in this study. The ROC curve of Scc-Ag level was calculated for the tumor recurrence, the optimal cut-off value of Scc-Ag level was set at 4 ng/mL (sensitivity, 0.636 and specificity, 0.678, p<0.001). After median follow-up time of 31.1 months, the 3-year RFS (68.1% vs. 88.2%, p<0.001) and OS (72.1% vs. 86.8%, p=0.005) rates were significantly higher in Scc- Ag ≥ 4 ng/mL arm than in Scc-Ag < 4 ng/mL arm. The locoregional recurrence (17.6% vs. 7.0%, p=0.003), para- aortic recurrence (9.4% vs. 2.1%, p=0.014), and distant metastasis (20.4% vs. 6.9%, p=0.002) rates at 3 years were significantly different between Scc-Ag ≥ 4 ng/mL and Scc-Ag < 4 ng/mL arms. Conclusion The elevated level of Scc-Ag over 4 ng/mL is expected to be a useful predictor of tumor recurrence and patient survival in patients with squamous-cell carcinoma of uterine cervix after definitive chemoradiation.