EP-1556 The effect of an endorectal balloon on GI toxicity after EBRT for localized prostate cancer. (April 2019) - Groen, V.; Kerkmeijer, L.; Monninkhof, E.; Van Schie, M.; Kunze-Busch, M.; De Boer, H.; Van der Heide, U.; Pos, F.; Haustermans, K.; Smeenk, R.J.