Radiation-induced gray matter atrophy in patients with nasopharyngeal carcinoma after intensity modulated radiotherapy: a MRI magnetic resonance imaging voxel-based morphometry study

Nasopharyngeal carcinoma (NPC) ranks the third most common malignant tumor among men in certain regions of East Asia, and it has a high incidence rate of 15 to 50 per 100,000 (1). Radiotherapy (RT) has long been adopted as the standard radical treatment method. However, when the skull base was infiltrated by the tumor and the superior retropharyngeal lymph nodes were treated at the same time, bilateral temporal lobes (TLs) of NPC patients’ were routinely exposed to high doses of radiation. The long-term survival chance for these patients usually exceeds 70%, and the potential for intellectual impairment and cognitive deficits such as impaired learning and memory can be observed after a few months to few years post-irradiation (2-4)