ESTRO 36 Abstract Book

S720 ESTRO 36 2017 _______________________________________________________________________________________________

metastases reported a pain flare (grade I), 5 patients with lymph node metastases reported diarrhea (grade I in three patients, grade II in two patients).

Pathological characteristics are summarized in Table 1. Two internal gold-fiducial markers were placed transperineally guided by transrectal ultrasound, in every patient before treatment. CTV was countered according to RTOG guidelines and expanded 3 mm posteriorly and 5 mm in all other direction to create the PTV. All patients underwent treatment with IMRT up to a total dose of 62.5Gy in 25fx (2,5Gy/day) in a Novalis linac. Daily verification was performed with IGRT-Exactrac®, and 6D- robotic couch. Six (26%) patients received androgen deprivation. Acute toxicity was assessed according to RTOG/EORTC criteria and was recorded weekly during treatment and one month after radiation therapy.

Conclusion SBRT might safely and effectively be used to postpone ADT in patients with oligometastatic recurrence of prostate cancer. EP-1357 moderate hypofractionated-imrt of prostate bed after radical prostatectom : acute toxicity J. Valero Albarran 1 , A. Ruiz Herrero 2 , A. Montero 1 , E. Sanchez 1 , E. Castro 3 , D. Olmos 3 , M. Hernandez 1 , R. Ciervide 1 , X. Chen 1 , B. Alvarez 4 , M. Garcia Aranda 4 , M. Lopez 1 , M. Serrano 5 , L. Osorio 6 , M. Asenjo 7 , P. Fernandez Leton 8 , A. Acosta 1 , O. Hernando Requejo 1 , C. Rubio 1 1 Hospital University HM Sanchinarro, Radiation Oncology, Madrid, Spain 2 Infanta Cristina Hospital, Radiiation Oncology, Madrid, Spain 3 Hospital University HM Sanchinarro, Medical Oncology, Madrid, Spain 4 Hospital University HM Sanchinarro Radiation Oncology Madrid, Radiation Oncology, Madrid, Spain 5 Hospital University HM Sanchinarro, Urology, Madrid, Spain 6 Hospital University HM Sanchinarro Radiation Oncology Madrid, Urology, Madrid, Spain 7 Hospital University HM Sanchinarro, Radiophisyc, Madrid, Spain 8 Hospital University HM Sanchinarro, Radiophisic, Madrid, Spain Purpose or Objective Hypofractionated radiation therapy as primary treatment for prostate cancer is currently being investigated in large phase 3 trials. However, evidences in post-operative setting are scarce. We report our experience about feasibility and acute toxicity of a moderate hypofractionated intensity modulated radiotherapy (Hypo-IMRT) schedule for prostate cancer (PC) after From October 2015 to July 2016, 23 patients (pts) were included for adjuvant (60,9%) or salvage radiation therapy (39,1%). They were classified with NCCN criteria in: low (2 pts), intermediate (13 pts) and high risk (8 pts). Median age was 63 years (range 55-77 years). Median PSA pretreatment was 0.31ng/mL (range 0.04 – 4.38ng/mL). radical prostatectomy. Material and Methods

Gleason score: 6 7(3+4) 7(4+3) 8-10 9% 35% 26% 30% Seminal vesicles invasion: -Yes -No 17% 83% Extracapsular extension: -Yes -No 61% 39% Positive Margin : -Yes -No 48% 52% Perineural invasion: -Yes -