MRI对鼻咽癌放疗后局部复发或残留的评估价值

The value of MRI in detection of local recurrences or residues of nasopharyngeal carci- noma after radiotherapy

目的探讨MRI影像学特征对鼻咽癌放疗后局部复发或残留的评估价值。方法鼻咽癌放疗后3个月～3年复查MRI诊断残留或复发患者47例，其中38例经病理证实为复发或残留。所有病例均行鼻咽颅底及颈部的MRI轴位T1wI、T2WI、SPIR，以及GD—DTPA增强扫描后T1WI轴位、矢状位扫描。在不同序列MRI图像上观察有无复发或残留肿瘤。结果本组38例MRI与病理诊断符合，其中鼻咽腔肿块21例，鼻咽腔外肿块17例；假阳性9例；诊断准确性为80．9％。鼻咽腔外肿块发生在咽旁间隙肿块11例，颅底骨质破坏8例，海绵窦受侵犯4例，眼眶受侵犯2例，副鼻窦及鼻腔侵犯5例，颅内侵犯3例。MRI增强扫描可见复发或残留处肿块呈明显强化。结论鼻咽癌放疗后局部残留或复发的原因多种多样，病变形态多样，侵及范围广；MRI增强扫描对评估鼻咽癌复发或残留具有重要价值，是鼻咽癌放疗后疗效判断重要的检查手段。

Objective To explore the value of MRI in the detection of local recurences or residues of nasopharyngeal carcinoma after radiotherapy. Methods 47 patients were diagnosed as local recurences or residues by MRI 3 months to 3 years after radiotherapy. 38 of the patients were confirmed by pathological examination. All the patients underwent MRI scans for nasopharynx, skull base and neck with axial T1WI, T2WI, and SPIR, and GD-DTPA enhanced T1WI axial and sagittal scans. MR1 images in different sequences were observed to identify recurrent or residual tumors. Results MRI diagnosis matched the pathological diagnosis in all the patients. 21 patients were diagnosed as nasal cavity masses, 17 nasopharyngeal masses, and 9 had false positive results with a diagnostic accuracy of 80.9%. Nasopha- ryngeal cavity masses orginated from parapharyngeal space occurred in 11 patients, destruction of skull base bone in 8, cavernous sinus invasion in 4, orbital invasion in 2, paranasal and nasal invasion in 5, and intracranial invasion in 3. Enhanced MRI scans revealed significant enhancement in the recurrent or residual masses. Conclusions The causes and shapes of local recurences or residues are varied and the lesions have a wide range of invasion. Enhanced MRI scan has a significant value in detection of recurrent or residual nasopharyngeal carcinoma and is the most important approach in assessing the efficacy of radiotherapy.