ESTRO 2021 Abstract Book

S1556

ESTRO 2021

Conclusion The relationship between optimal dose-volume histograms and a good treatment preparation, such as the rectum and bladder filling, is well-known, but this retrospective analysis highlighted it quantitatively. Large rectum EIVs indicate a more difficult optimization due to a large OAR area facing the target. The bladder analysis instead underlined the linear correlation with bladder volume outside the PTV. Furthermore, this quantitative dosimetric analysis is the base of a consequent institutional standard improvement: the highlighted relationships will be in-deep analyzed to determine customized lower achievable dose constraints before treatment planning. PO-1826 A tool to standardize plan quality in moderate hypofractionated prostate radiotherapy S. Trivellato 1 , P. Caricato 1,2 , V. Faccenda 1,2 , G. Montanari 1 , V. Tremolada 1 , R. Lucchini 3,4 , D. Panizza 1,4 , S. Arcangeli 3,4 , E. De Ponti 1,4 1 ASST Monza, Medical Physics Department, Monza, Italy; 2 University of Milan, Department of Physics, Milano, Italy; 3 ASST Monza, Department of Radiation Oncology, Monza, Italy; 4 University of Milan Bicocca, School of Medicine and Surgery, Monza, Italy

Purpose or Objective