Radiation-induced dysphagia in head and neck cancer patients: MRI-based study

头颈部癌症的放射治疗（RT）已知会引起吞咽困难并导致吞咽肌肉的形态学变化。本研究探讨鼻咽癌患者放疗后MRI可检测到的咽缩肌（PCM）的宽度和信号强度比（SIR）、咽旁间隙的SIR以及咽后间隙的宽度的变化。2007年4月至2014年3月间22例接受放疗的鼻咽癌患者，放疗后PCMs厚度明显增加，T1-SIR降低，T2-SIR升高。咽旁间隙的T1和T2-SIR显著降低。咽后间隙宽度增加。在早期和晚期吞咽困难的2级和3级之间，PCM的宽度和SIR、咽旁间隙的SIR和咽后间隙的宽度的变化没有差异。

Radiation therapy (RT) for head and neck cancer is known to induce dysphasia and cause morphologic changes in the muscles of swallowing. This study investigated the changes in the width and signal intensity ratio (SIR) of the pharyngeal constrictor muscles (PCM), SIR of the parapharyngeal space, and the width of the retropharyngeal space detectable by MRI after RT for nasopharyngeal cancer patients. Twenty-two patients receiving RT for nasopharyngeal cancer between April 2007 and March 2014 were enrolled in this study.The patients receiving RT had significant increased thickness, decreased T1-SIR, and increased T2-SIR in PCMs. T1- and T2-SIRs in the parapharyngeal space decreased significantly. And increased width of the retropharyngeal space was noted. The changes in the width and SIR of the PCM, SIR of the parapharyngeal space, and the width of the retropharyngeal space did not differ between Grade 2 and Grade 3 in both early and late dysphagia.