ESTRO 2025 - Abstract Book

S4370

RTT - Treatment planning, OAR and target definitions

ESTRO 2025

Conclusion: The small standard deviation over 5 fractions, translated to contouring differences of about 0.2 mm, suggesting a high consistency in daily contouring. Hormonal therapy and fraction dose have a significant, but small influence on the prostate. When PTV margins of 3 mm are used, changes in prostate volume mostly don’t require re-contouring, allowing for more time-efficient methods such as ‘adapt to position’ or ‘adapt to rotation’.