This study evaluated three-dimensional geometric distortion of six selected potential MR sequences for radiotherapy applications, acquired from a 1.5T 700mm-wide bore MR-simulator. Every sequence was investigated in three acquisition-orientations and multiple receiver-bandwidths, under various diameter-sphere-volume (DSVs). A large geometric accuracy phantom was constructed to quantify the distortion within the largest field-of-view allowed. Detailed distortion statistics, evaluation based on distortion requirements of different radiotherapy applications and comparison among sequences were reported. Results showed that sequence-types and acquisition-orientations were more influential to distortion than receiver-bandwidths. The distortion statistics are also a valuable guideline for sequence selection and optimization for radiotherapy.