Clinical implementation and feasibility of long-course fractionated MR-guided chemoradiotherapy for patients with esophageal cancer: An R-IDEAL stage 1b/2a evaluation of technical innovation. - Boekhoff MR; Bouwmans R; Doornaert PAH; Intven MPW; Lagendijk JJW; van Lier ALHMW; Rasing MJA; van de Ven S; Meijer GJ; Mook S (Clinical and translational radiation oncology, 2022)