ESTRO 2022 - Abstract Book

S1204

Abstract book

ESTRO 2022

Gy; p = 0.630) (Fig. 2). For both structures the spread of the planned dose per fraction was wider for the simulated ATP plans compared to the ATS plans. Fig. 1: Planned simulated ATP dose and planned ATS dose for the spared neurovascular bundles.

Fig. 2: Planned simulated ATP dose and planned ATS dose for the spared internal pudendal arteries.

Conclusion For the NVB, the mean D0.1cc was significantly lower in the ATS plans compared to the simulated ATP plans. The dose spread of the NVB and IPA of the 5 fractions was narrower in the ATS plans. These early results support the use of MRgRT for daily contouring in neurovascular-sparing treatment. Within the next months, more trial patients will be treated and analyzed.

PO-1421 Is it possible to deliver on-line MR-guided RT for prostate cancer within a feasible time frame?

T. Schytte 1 , P.K. Møller 1 , U. Bernchou 2 , K.L. Gottlieb 3 , E.L. Lorenzen 4 , S. Agergaard 2 , H.R. Jensen 3 , C.J. Nyborg 1 , L. Dysager 1 , O. Hansen 5 , F. Mahmood 2 , R. Bahij 5 , C. Brink 2 , A.S. Bertelsen 3 1 Odense University Hospital, Oncology, Odense , Denmark; 2 Odense University Hospital, Laboratory of Radiation Physics, Odense, Denmark; 3 Odense University Hospital, Laboratory of Radiation Physics, Odense , Denmark; 4 Odense University Hospital, Laboratory of Radiation Physics, Odense University Hospital, Denmark; 5 Odense University Hospital, Oncology, Odense, Denmark Purpose or Objective The PRISM-OUH protocol (Prostate Radiotherapy Integrated with Simultaneous MRI) has included patients with localized prostate cancer treated on the 1.5 T MR-linac (Unity, Elekta AB, Stockholm, Sweden). The protocol aimed to assess the feasibility, safety, and tolerability of the adaptive treatments. The primary endpoint was to evaluate whether on-line MR-