Fig. 1.

Flowchart describes the procedures of MR examinations and radiotherapy (RT) for patients with nasopharyngeal carcinoma. Pre-MR and post-MR are the MR examinations within 2 weeks before RT (pre-RT) and 4 weeks after RT (post-RT), respectively. CT reset scanning proceeded approximately 5 weeks after the beginning of RT for the formulation of the second course RT scheme