Induction therapy with ipilimumab and nivolumab followed by consolidative chemoradiation as organ-sparing treatment in urothelial bladder cancer: study protocol of the INDIBLADE tr... oleh C.F. Stockem, J.J.J. Mellema, B.W.G. van Rhijn, T.N. Boellaard, M.L. van Montfoort, S. Balduzzi, J.L. Boormans, M. Franckena, R.P. Meijer, D.G.J. Robbrecht, B.B.M. Suelmann, E.E. Schaake, M.S. van der Heijden