鼻咽癌放疗后CT影像变化规律探讨

The Changing Order of Nasopharyngeal Carcinoma after Radiotherapy on CT Image

目的:探讨鼻咽癌放疗后CT、影像变化规律。材料与方法:放疗后无瘤生存3年以上,并有较完整各时段CT复查资料的鼻咽癌患者56例,按92’鼻咽癌分期T_113例、T_219例、T_317例、T_49例。总结分析患者放疗前、放疗结束时、放疗后2～9月、放疗后1～2年、放疗后2年以上鼻咽CT影像变化特点。结果:放疗结束时,73.2％(41/56)鼻咽结构基本恢复正常,26.8％(15/56)患侧鼻咽局部仍增厚;放疗后2～9月,89.3％(50/56)咽壁肿胀增厚,咽腔变形、变窄;放疗后1～2年咽壁肿胀增厚逐渐减轻、僵直;放疗后2年以上85.7％(48/56)咽壁变薄、僵直,咽腔扩大。咽旁间隙狭窄放疗结束时61.1％(22/36)恢复正常;放疗结束时未恢复正常者,放疗后恢复呈渐进过程,放疗后3年仍有8.3％(3/36)未恢复正常。颅底骨质破坏难以完全修复,部分患者可部分修复。副鼻窦侵犯者88.9％(8/9)放疗结束时肿瘤完全消退。全组放疗后100％在不同时期出现过不同程度的副鼻窦炎,放疗2年以后明显减少、减轻。结论:鼻咽癌放疗后CT影像表现随时间变化有一定规律。探讨和掌握这些规律,对减少鼻咽癌放疗后CT误诊复发具有重要参考价值。

Objective: To search the changing orders of nasophargngeal carcinoma after radiotherapy on CT image. Methods: CT images of 56 cases with NPC, who were diagnosed being free from tumor more than three years after radiotherapy were studied. The patients were staged according to the 92' stage classification with the following distribution: T113,T219,T3l7,T49. The CT follow-up progress was plot out to 4 sections to summarize and analyze the images' characteristics at different phase; immediate after radiotherapy, 2-9 months after radiotherapy, 1 - 2 years after radiotherapy, 2 years or more after radiotherapy. Results; The nasophargx in 73. 2% (41/56) of the patients came back to normal and 26. 8% (15/56) patients with local incrassation at the primary position, immediately after radiotherapy. Nasophargeal edema appeared in 89. 3% (50/56) of the patients 2 - 9 months after radiotherapy. The nasopharyngeal cavity enlarging and the nasopharyngeal wall thinning happened in 51. 8% (29/56) and 85. 7% (1/56) of the patients, 1 - 2 years and more than 2 years after radiotherapy respectively. The parapharyngeal space of 61. 1% (22/36) of the patients resumed immediately after radiotherapy, and the other patients' resumig progress was gradual, 8. 3% (3/36) of the patieiss didn't resume 3 years after radiotherapy. Reconstruction of bony destruction of the skull base was difficult, just a part of the patients could reconstruct incompletely. The tumor focus involved paranasal sinus disappeared completely in 88. 9% (8/9) of the patients immediately after radiotherapy. Nasosinusitis appeared in ail of the patients in this group at different period after radiotherapy, and alleviated 2 years after radiotherapy. Conclusion: There are some orders about CT image changing to NPC at different time after radiotherapy, which might be favorable to reducing CT misdiagnose of local failure.