ESTRO 38 Abstract book

S843 ESTRO 38

83.2 Gy), while in series with BRT boost, median total dose was 78.0 Gy (range: 56.0-96.0 Gy). Median acute G ≥ 3 GU and GI toxicities were 2.0% (range: 0.0-7.0%) and 0.0% (0.0-5.0%), respectively. Median Late G ≥ 2 GU and GI toxicities reported were 7.5% (0.0-39.0%) and 6.3% (0.0- 21.0%), respectively. Median 5-year bDFS was 94.0% (range: 70.5-98.0%). Conclusion Based on our analysis, the strategy of boosting the DIL is correlated with reasonable toxicity and excellent results in terms of bDFS. EP-1562 CyberKnife or HDR Brachytherapy Alone for the Treatment of Prostate Cancer: A Matched Pair Analysis P. Wojcieszek 1 , G. Głowacki 2 , T. Krzysztofiak 1 , P. Lelek 1 , M. Szlag 3 , A. Cholewka 3 , M. Fijałkowski 1 , S. Kellas- Ślęczka 1 , K. Krysiak 1 , L. Miszczyk 4 1 Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Brachytherapy Department, Gliwice, Poland ; 2 COiDO, Radiotherapy, Tomaszów Mazowiecki, Poland ; 3 Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Radiotherapy Planning Department, Gliwice, Poland ; 4 Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Radiotherapy Department, Gliwice, Poland Purpose or Objective To evaluate the efficacy and morbidity of CyberKnife (CK) compared to high-dose-rate (HDR) brachytherapy alone. Material and Methods Two independent prospective trials were conducted in our cancer centre between 2008 and 2015. Outcome blinded patients from both trials exceeding six months of the follow-up were matched 1:1 with following criteria: Gleason score, maximum PSA, T stage, D’Amico risk, Age. No high-risk patients were allowed in this analysis. Wilcoxon rank test was used to assess the differences among the groups. Kaplan-Meier method, log-rank test and Cox regression model were used to analyse the biochemical recurrence-free survival. Results One hundred ninety patients were enrolled in this study. There were no statistically significant differences among the two cohorts except for the age. Median follow-up for HDR and CK was 48 months (16-120 mo) and 52 months (9- 74 mo), respectively. HDR was linked with higher mild genitourinary toxicity (p-0.03), while CK was associated with higher gastrointestinal morbidity (p-0.002). There was no difference in the time to achieve nadir PSA. Biochemical relapse-free survival was higher in the HDR cohort with no statistical significance (94% vs 88%; p-0.11). There were no differences in the overall survival. Conclusion HDR alone and CK are safe with comparable outcomes. Less invasive treatment may be considered for older patients with good prognosis. A randomised controlled study should be designed to consider the best options for different groups of prostate cancer patients. EP-1563 PSMA-ligand based radiotherapy for lymph node relapsed prostate cancer after radical prostatectomy C. Henkenberens 1 , N. Schmidt-Hegemann 2 , M.M.E. Vogel 3 , S. Kirste 4 , J. Becker 5 , C. Belka 2 , S.E. Coombs 3 , A. Grosu 4 , M. Arndt-Christian 5 , S.G.C. Kroeze 6 , M. Guckenberger 6 , H. Christiansen 1 , D. Walacides 1 1 Medical School Hannover, Department of Radiotherapy and Special Oncology, Hannover, Germany ; 2 University Hospital LMU, Department of Radiation Oncology, Munich, Germany ; 3 Technical University Munich, Department of Radiation Oncology, Munich, Germany ; 4 University of Freiburg, Department of Radiation Oncology, Freiburg, Germany ; 5 University Hospital Tübingen, Department of Radiation Oncology, Tübingen,

Conclusion Compared to baseline QoL, a transient increase of urinary symptoms was seen in the acute and late phase, and sexual function temporarily deteriorated in the first six months. Bowel symptoms did not increase after focal salvage HDR-BT. In contrast with the side-effects associated with ADT, this treatment has very low impact on QoL of recurrent prostate cancer patients. EP-1561 Prostate cancer radiotherapy: a systematic review about boost on the dominant intraprostatic lesion S. Cammelli 1 , M. Buwenge 1 , S. Giambattista 1 , A. Zamagni 1 , E. Galofaro 1 , P. Valeria 1 , M. Ntreta 1 , E. Alexopoulou 2 , M. Ferro 3 , E. Arena 3 , G. Macchia 3 , F. Deodato 3 , S. Cilla 4 , I. Djan 5 , G.P. Frezza 6 , A.G. Morganti 1 1 Radiation Oncology Center, Dept. of Experimental- Diagnostic and Specialty Medicine – DIMES- University of Bologna- S.Orsola-Malpighi Hospital, Bologna, Italy ; 2 Department of Radiation Oncology, University of Patras Medical School, Patras, Greece ; 3 Radiotherapy Unit, Fondazione di Ricerca e Cura "Giovanni Paolo II", Campobasso, Italy ; 4 Medical Physics Unit, Fondazione di Ricerca e Cura "Giovanni Paolo II", Campobasso, Italy ; 5 Institute of Oncology Vojvodina, Medical Faculty- University of Novi Sad, Novi Sad, Serbia ; 6 Radiation Oncology Unit, Bellaria Hospital, Bologna, Italy Purpose or Objective Local recurrence has been shown to originate within the initial tumor in prostate cancer (PCa). Modern imaging allows identification of dominant intra-prostatic lesions (DIL). Evidence suggests that higher radiotherapy (RT) doses result in increased biochemical control, but dose escalation to the whole prostate is limited by the surrounding normal tissues tolerance. Therefore, a systematic review was conducted to analyse the current evidence of RT boost to DIL and assess toxicity and PubMed Electronic database was searched through 9th April 2018 for clinical studies on DIL boost irradiation published in English. Established inclusion criteria were: ≥ 15 number of patients, localized PCa, and only clinical studies with planned boost to the DIL. Results Thirteen studies with a total of 1044 patients (range: 15- 239) reported on a boost to DIL. In all studies, functional imaging was used in DIL delineation to correlate with the histopathological findings. Boost RT to DIL-PTV was delivered using hypofractionated image-guided RT techniques. In series where boost RT was delivered by IMRT-SIB, median dose to DIL was 82.0 Gy (range: 74.0 - biochemical outcome. Material and Methods