Author contributions
M.R. and E.R. conceived and designed the trial, coordinated trial procedures, analysed, and interpreted the clinical data, and wrote the manuscript. M.R., E.R., Co.D. included and treated patients in the trial. P.L. analysed and interpreted clinical data and wrote the manuscript. E.R. conceived and supervised the immune monitoring experiments. G.V. analysed and interpreted translational data and wrote the manuscript together with E.T. E.T. contributed to FACS staining and analysis. M.M., L.B., and Ca.D. included patients in the trial and delivered radiation therapy. V.F., E.L., and N.P. included patients and performed the majority of biopsies. La.L. performed the histological analyses. D.M. and A.V.-S. supervised the histological analyses. S.V. performed NGS and transcriptomic sequencing. Lo.L. performed the bioinformatic analyses of NGS and transcriptomic sequencing. N.S. and I.B. supervised the NGS and transcriptomic sequencing and the related bioinformatic analyses. M.C. performed the statistical analysis of the clinical data. C.M., V.H., and L.C. performed the assessment of pelvic MRI and PET-CT scans. Z.C.-A. and G.M. helped with trial coordination. M.K. gave input on trial design, coordinated tissue biobanking, and gave input on NGS and transcriptomic sequencing analyses. S.A. and O.L. advised on the immune monitoring analyses. All authors edited and approved the manuscript.