Poon M, et al. – Analysts conducted a retrospective study to assess the dosimetric accuracy of applying deformed conventional CT images for dose calculations, in the hope of inferring the utility of adaptive radiotherapy (ART) using planning CT (PCT) images that deformed to up–to–date cone–beam computed tomography (CBCT) images for patients with nasopharyngeal carcinoma (NPC). Owing to unknown clinical significanceof dose deviation results obtained from this study, it was demonstrated that a conventional CT scan is still n for replanning in patients with nasopharyngeal carcinoma who are experiencing significant anatomical changes during the course of radiation treatment.