ESTRO 2022 - Abstract Book

S1171

Abstract book

ESTRO 2022

Conclusion CBCT guided SBRT and online correction allows a safe target and organ at risk monitorization, permitting a high dose delivery with an excellent acute toxicity profile. Efficacy results will be reported once appropriate follow up is reached.

PO-1382 Moderate hypofractionation for prostate cancer with fiducials markers

J.G. Molina Osorio 1 , G. Meca Santamaria 2 , M. Villalobos Monardes 1 , S. Moreno López 1 , R. Ballester Alabau 3 , A. Álvarez Gracia 1 , S. Comas Anton 1 , J. Jové Teixido 2 , M. Caro Gallarin 2 , L. Prats Cabeces 4 , E. Luguera Sanchez 4 , J. Molero Savall 4 , S. Villà Freixa 5 1 Institut Català d'Oncologia, Radiation Oncology, Badalona (Barcelona), Spain; 2 Institut Català d'Oncologia. , Radiation Oncology, Badalona (Barcelona), Spain; 3 Institut Català d'Oncologia , Radiation Oncology, Badalona (Barcelona), Spain; 4 Institut Català d'Oncologia, Medical Physics, Badalona (Barcelona), Spain; 5 Institut Català d'Oncologia, Radiation Oncology , Badalona (Barcelona), Spain Purpose or Objective Hypofractionated radiotherapy for prostate cancer has become a new gold standard. Otherwise It has been described that the use of fiducials markers implanted within the prostate allows significant reduction of PTV margins, and this could be related with decreased toxicity. The purpose of this study was to analyze toxicity of moderate hypofractionation with fiducial guide radiotherapy for prostate cancer patients. Materials and Methods Between August 2018 and July 2021, 167 patients with prostate cancer were selected to receive radiotherapy at dose of 60 Gy in 20 fractions over 4 weeks. Three gold fiducials markers were implanted within prostate before the treatment planning procedure. Radiation was delivered using VMAT (Volumetric Modulated Arc Therapy) technique with 6 MV photon beams. Daily image guide control with CBCT was performed. Toxicity was evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE) v5.0.