鼻咽癌放疗后MRI分析

MRI Analysis in Nasopharyngeal Carcinoma after Radiotherapy

目的提高对鼻咽癌(NPC)放疗后改变及复发的MRI表现的认识。方法详细分析经临床和病理证实的48例NPC放疗后复查的MRI资料。结果NPC放疗后无复发组28例,其中鼻咽腔正常2例,鼻咽腔变形15例,鼻咽壁增厚19例,茎内增厚7例,咽旁间隙变窄3例,颅底残留破坏缺损5例。复发组21例,鼻咽壁和茎内增厚各12例,颅底骨质破坏18例,颞下窝肿块4例,口咽肿块2例,眼眶、上颌骨/上颌窦骨质破坏2例,颞颌关节骨质破坏1例,乳突骨质破坏、双侧腮腺肿块及环绕颈部浸润肿块1例,咽旁间隙变窄/消失9例。经统计学处理,在茎内增厚、咽旁间隙变窄/消失方面,两组间均有显著性差异(P<0.05)。无复发组中,7例茎内增厚在T1WI和T2WI上均表现为茎内软组织等信号或低信号肿块影,5例无强化,2例轻度强化;复发组中,12例茎内增厚在T1WI和T2WI上表现为形态不规则的等信号或略高号肿块影,11例行增强扫描,明显强化9例,轻度强化2例。结论MRI可以很好地显示NPC放疗后变化,尤其是对放疗后纤维化斑块与肿瘤复发的鉴别有重要作用。

Objective To improve the recognization of the recurrence and changes of MRI in nasopharyngeal carcinoma （NPC） after radiotherapy. Methods MRI of 48 patients confirmed by followed-up or pathology in NPC after radiotherapy were analyzed in details. Results In the 28 non-recurrent cases, justo of cavum nasopharyngeum（n=2）,distortion of cavum nasopharyngeum（n=15）, nasopharyngeal wall thicken（n=19）, medial soft tissue of styloid process （MSTSP） thicken（n=7）, narrowing of parapharyngeal space（n=3）, skull base residues encroached（n=5）. In the 21 recurrent cases,each nasopharyngeal wall and MSTSP thicken （n=12）, skull base destruction（n=18）, tumor in infratemporal fossa（n=4）, tumor in oropharynx（n=2）, fossa orbitalis, maxilla and maxillary sinus invaded （n=2）, temporomandibular joint invaded（n= 1）, in 1 case with mastoid process invaded and tumor of bilateral parotid glands and encircling collare, narrowing or disappearance of parapharyngeal space （n=9）. By statistical analysis, there were significant difference between the non-recurrent and the recurrence in （P〈0.05）, among the MSTSP thicken and narrowing or disappearance of parapharyngeal space. In the nonrecurrent, 7 cases with MSTSP thicken were displayed with a tumor of isointensity to hypointensity on T1WI and T2WI; on the enhanced MRI, 5 cases with no enhancement, 2 cases with slight enhancement. In the recurrence, 12 cases with MSTSP thicken were displayed with a irregular mass of isointensity to hyperintensity on TlWI and T2WI; 11 cases were done with enhanced MRI, 9 cases with strong enhancement, 2 cases with slight enhancement. Oonclusion MRI can show the changes in NPC after radiotherapy, especially playing an important role in differentiating recurrent NPC from radiofibrosis.