ESTRO 2021 Abstract Book

S1098

ESTRO 2021

GS was not determined because of too small samples from the biopsy. Median biochemical recurrence-free survival (BRFS) was 90 months, 2- and 5-year BRFS was 80.9% and 63.3%, respectively. Median local recurrence-free survival (LRFS) and metastasis-free survival (MFS) was 108.3 months and 107.6 months, respectively. Whereas, 2- and 5-year LRFS was 93.5% and 81.6%, respectively, 2- and 5-year MFS was 89% and 72.7%, respectively. There was no correlation between assessed survival parameters and initial treatment, Gleason pattern, or PSA concentration at recurrence.

Conclusion Salvage HDR-BT is an efficient treatment of localised prostate cancer relapse after primary irradiation. However, the selection of candidates for this treatment should be carried out carefully with the consideration of the individual risk of distant failures. PO-1337 Long Follow Up Of Late Toxicity After Hypofractionated Postoperative Radiation In Prostate Cancer J. Valero 1 , M. Izquierdo Merchán 2 , Á. Montero Luis 3 , O. Hernando Requejo 4 , X. Chen 4 , E. Sanchez Saugar 5 , B. Álvarez Rodríguez 6 , M. Núñez Báez 7 , R. Ciérvide Jurio 8 , M.D.L.O. García-Aranda Pez 6 , M. López González 9 , P. Fernández Letón 10 , J. Martí Asenjo 10 , A. Prado Barragán 10 , R.M. Alonso 11 , K.D. Rossi Coronado 12 , C. Rubio Rodríguez 6 1 Hospital Universitario HM Sanchinarro -Puerta del Sur. HM Hospitales, Radiation Oncology, Spain, Spain; 2 Hospital Universitario HM Sanchinarro.Puerta del Sur HM Hospitales , Radiation Oncology, Madrid , Spain; 3 Hospital Universitario HM Sanchinarro.Puerta del Sur. HM Hospitales , Radiation Oncology, Madrid , Spain; 4 Hospital Universitario HM Sanchinarro. Puerta del Sur.HM Hospitales , Radiation Oncology, Madrid , Spain; 5 Hospital Universitario HM Sanchinarro. Puerta del Sur. HM Hospitales, Radiation Oncology, Madrid , Spain; 6 Hospital Universitario HM Sanchinarro. HM Hospitales, Radiation Oncology, Madrid, Spain; 7 Hospital Universitario HM Sanchinarro. HM Hospitales, Radiation Oncology, Madrid , Spain; 8 Hospital Universitario HM Sanchinarro. Puerta del Sur. HM Hospitales, Radiation Oncology, Madrid, Spain; 9 Hospital Universitario HM Sanchinarro.Puerta del Sur. HM Hospitales, Radiation Oncology, Madrid, Spain; 10 Hospital Universitario HM Sanchinarro. HM Hospitales, Medical Physics , Madrid, Spain; 11 Hospital Universitario HM Sanchinarro. Puerta del Sur. HM Hospitales, Radiation Oncology , Madrid, Spain; 12 Hospital Universitario HM Sanchinarro. Puerta del Sur.HM Hospitales, Radiation Oncology, Madrid, Spain Purpose or Objective The aim of this study was to evaluate tolerance profile of a moderate hypofractionated scheme with long follow up for patients with prostate cancer (PC) who underwent prostatectomy. Materials and Methods From June 2015 to June 2018, 63 patients (p) with PC who underwent prostatectomy, were included. All patients were recommended to receive adjuvant (21 patients) or salvage (42 patients) radiotherapy (RT). Median age was 62 years (range 45 – 75 years). 51% of patients (32p) had previous urinary incontinence: 31 patients with grade 1-2 and 2 patients with grade 3. Two internal gold-fiducial markers were placed transperineally, guided by transrectal ultrasound, before treatment, without complications derived of the procedure. CTV was countered according to RTOG guidelines including surgical bed of prostatectomy and expanded 3 mm posteriorly and 5 mm in all other direction to create PTV. Median PTV volume (cm 3 ) is 164.86 cm 3 and median bladder volume (cm 3 ) is 24.409 cm 3 . All patients underwent treatment with image guided IMRT/VMAT to a total dose of 65Gy in 25 fractions, at 2,5Gy/day (EQD2Gy for a/b=1.5 of 70 Gy). Treatments were delivered in Novalis and Elekta Linac with daily IGRT (Exactract®/CBCT- Clarity 3D ultrasound system) in 54 patients with fiducial marker and in 9 patients without fiducial marker. Seven patients (11%) received concomitant androgen deprivation therapy. Acute and late toxicities were assessed using Common Terminology Criteria for Adverse Events vs4.0 and Toxicity was assessed according to RTOG/EORTC criteria, respectively. Institutional review board approved this study. Results All patients completed radiotherapy. Median follow up was 47months (range 32-64 months ). All patients but