ESTRO 2020 Abstract book

S685 ESTRO 2020

A total of 115 pts with mUC, 96 men (83,5%), median age 68 years old, 95 pts (82.6%) with ECOG 0-1, bladder primary in 101 (87.8%), transitional histology in 103 pts (89.6%), were treated with ICIs because of metastaic progression. Nodal progressive disease was present in 88 pts (76.5%), lung metastases (met) in 45 (39.1%), liver met in 23 (20%) and bone met in 27 (23.5%). RLT previously performed to ICIs was a radical cystectomy in 62 (53.9%) and radical radiotherapy in 7(6.1%). In 46 pts (40%) no RLT was done. ICIs prescribed were atezolizumab (55.7%), pembrolizumab (16.5%), durvalumab (11.3%), durvalumab/tremelimumab (7.8%), nivolumab (5.2%) and avelumab (3.5%). Median OS was 11.23 mo (95% IC; 6.02-16.44) and 7.95 mo (95%IC; 5.15-10.75) for group A and group B, respectively (P=0.481). Progression Free Survival (PFS) was 5.29 mo (95%IC; 2.01-8.56) for the RLT group vs 2.62 mo (95% IC; 1.20-4.04) for the non local treatment pts (P=0.306). The disease control rate (CR [6.9%] +PR [9.6%] +SD [14.1%]) was higher for pts with previous RLT compared to those pts who did not receive RLT (CR [3.2%] + PR [5.8%] + SD [6.4%], this difference was no statically significant (P=0.325). Conclusion Despite the results did not meet statistical significance, these are hypothesis generating and might suggest that RLT could play a role in the outcome of pts with mUC treated with ICIs. The true value of this approach remains to be demonstrated in prospective studies PO-1211 Stereotactic radiotherapy combined with immune- or targeted therapy for renal cell cancer patients. S. Kroeze 1 , C. Fritz 1 , S. Siva 2 , K.H. Kahl 3 , N. Sundahl 4 , O. Blanck 5 , D. Kaul 6 , A.L. Grosu 7 , J.J.C. Verhoeff 8 , G. Skazikis 9 , F. Roeder 10 , M. Geier 11 , F. Eckert 12 , M. Guckenberger 1 1 University Hospital Zürich, Radiation Oncology, Zurich, Switzerland ; 2 Peter MacCallum Cancer Centre, Radiation Oncology, Melbourne, Australia ; 3 University Hospital Augsburg, Radiation Oncology, Augsburg, Germany ; 4 University Hospital Ghent, Radiation Oncology, Ghent, Belgium ; 5 University Medical Center Schleswig-Holstein, Radiation Oncology, Kiel, Germany ; 6 Charité-University Hospital Berlin, Radiation Oncology, Berlin, Germany ; 7 University Medical Center Freiburg, Radiation Oncology, Freiburg, Germany ; 8 University Medical Center Utrecht, Radiation Oncology, Utrecht, The Netherlands ; 9 Schwarzwald-Baar Klinikum, Radiation Oncology, Villingen-Schwenningen, Germany ; 10 University Hospital Munich, Radiation Oncology, Munich, Germany ; 11 Ordensklinikum Linz, Radiation Oncology, Linz, Austria ; 12 University Hospital Tübingen, Radiation Oncology, Tübingen, Germany Purpose or Objective Approximately 2/3 of renal cell carcinoma (RCC) patients will present with, or develop metastatic disease. Treatment with tyrosine kinase inhibitors (TKI) or immune checkpoint inhibitors (ICI) has improved their prognosis significantly. However, when progression under these therapies occurs, second-line options usually show low response rates. Therefore, a multidisciplinary approach with a localized treatment is increasingly performed. Stereotactic radiotherapy (SRT) results in high local response rates and has now been included in the NCCN guidelines for mRCC patients. The aim of this study was to analyze the effectivity and safety of stereotactic radiotherapy (SRT) in mRCC patients receiving targeted- or immunotherapy. Material and Methods Data on mRCC patients was extracted from the retrospective international multicenter register study (TOaSTT) investigating SRT concurrent (≤30d) to TKI/ICI. Overall survival (OS), progression free survival (PFS), local

BioXmark fiducials markers at the tumorborders on a CT scan showing at the borders of a bladder tumor.

two examples of blurring\diffuse spreading of lipiodol through the bladder wall, inaccurate for delineating purposes. Conclusion The novel BioXmark® liquid fiducial marker appears to be safe, easy injectable, stable over time and showed sustained visibility in the use for daily-online adaptive IGRT for bladder preserving chemoradiotherapy in muscle- invasive bladder cancer. PO-1210 Local treatment on the outcome of immune- checkpoint inhibitors in metastatic urothelial carcinoma J. Maldonado 1 , R. Morales Barrera 2 , N. Vidal 3 , N. Feltes 4 , M. Domenech 5 , J. Puente 3 , M. Figols 5 , M. González 2 , F. Lozano 6 , H. López 5 , E. Gallardo 7 , D. Moreno 1 , C. Suárez 2 , J. Morote 6 , J. Carles 2 , J. Giralt 1 1 Hospital Universitario Vall d'Hebron, Radiation Oncology, Barcelona, Spain ; 2 Hospital Universitario Vall d'Hebron, Medical Oncology, Barcelona, Spain ; 3 Hospital Universitario Puerta de Hierro, Medical Oncology, Madrid, Spain ; 4 Hospital de Terrassa, Radiation Oncology, Terrassa, Spain ; 5 Althaia_ Hospital Sant Joan de Deu, Medical Oncology, Manresa, Spain ; 6 Hospital Universitario Vall d'Hebron, Urology, Barcelona, Spain ; 7 Hospital Universitari Parc Taulí, Medical Oncology, Sabadell, Spain Purpose or Objective Immune checkpoint inhibitors(ICIs) bring patients (pts) with metastatic urothelial carcinoma (mUC) to new scenarios. Moreover recent retrospective studies have reported the potential benefit of radical local (RLT) treatment to primary bladder cancer in pts with metastatic disease. We evaluate if a previous RLT in pts with mUC treated with ICIs impacts in the outcome Material and Methods Data from a multi-institutional database of pts with mUC treated with ICIs was evaluated from May 2013 to May 2019. Stratification was made according previous RLT with ICIs versus no RLT with ICIs. RLT was defined as radical surgery or external beam radiotherapy (>50 Gy) delivered to the bladder. A descriptive analysis was performed to assess oncologic outcomes. The X 2 test was used to determine differences in rates. Overall survival (OS) in previously RLT pts plus ICIs (group A) versus no RLT pts plus ICIs (group B) was generated using Kaplan-Meier method and results were compared with a log-rank test. OS was calculated from the date of initiation of ICI to the date of death. Analyses were performed using SPSS v21 Results