鼻咽癌放疗后局部复发和纤维化的增强CT鉴别诊断价值

目的探讨鼻咽癌放疗后出现块影时,ＣＴ检查对鉴别肿瘤局部复发和放射性纤维化的价值。方法收集１５９例经ＣＴ检查的鼻咽癌,其中放疗后局部复发（ＲＴ）３７例,放射性纤维化（ＲＦ）５４例,以６８例未经放疗的鼻咽癌（ＰＴ）作对比。使用ＥＬＳｃｉｎｔｓｐｒｉｎｔ２０００型ＣＴ机,测量放疗后出现的块影平扫和强化的ＣＴ值,用统计学的方差分析法处理增强前后的ＣＴ值差异。结果ＲＴ组平扫ＣＴ值为５０．４０±８．１０Ｈｕ,增强为７３．７４±７．３７Ｈｕ;ＲＦ组平扫为４８．６２±１０．１５Ｈｕ,增强为５６．７４±８．６９Ｈｕ;对照组（ＰＴ）病变区平扫为４８．３２±９．２０Ｈｕ,增强为７２．３８±７．７５Ｈｕ。测量表明ＲＴ组有明显强化,ＲＴ组与ＲＦ组强化后ＣＴ值差异有非常显著性（Ｐ＜０．０１）。结论鼻咽癌放疗后出现块影时,ＣＴ增强扫描可作为鉴别诊断的重要方法。

Evaluation of enhanced CT examination in the differential diagnosis of local recurrence and postradiation fibrosis in nasopharyngeal carcinoma

OBJECTIVE: To evaluate enhanced CT examination in the differential diagnosis of local tumor recurrence and postradiation fibrosis when a mass appeared is observed after radiation therapy of carcinoma of nasopharynx. METHODS: 159 cases of nasopharyngeal carcinoma were examined by CT, including 37 cases of local recurrence(RT) after radiation therapy and 54 cases of postradiation fibrosis (RF) 68 cases of nasopharyngeal carcinoma (PT) before radiation therapy sened as comparison. Elscint sprint 2000 CT machine was used. The CT number of plain and enhanced examination of the mass appearing after radiation therapy were measured. Variance analysis was used as statistical management for CT number difference of different kinds of mass lesions before and after contrast enhancement. RESULTS: In the RT cases, the average CT number of the mass lesion for plain scan were 50.40 +/- 8.10 Hu, and for enhanced scan it was 73.74 +/- 7.37 Hu. In the RF cases plain scan 48.62 +/- 10.15 Hu, enhanced scan 56.74 +/- 8.69 Hu, In the control cases (PT), the CT number in the plain scan of lesion was 48.32 +/- 9.20 Hu, and 72.38 +/- 7.75 Hu in the enhanced examination. These measurement showed obvious enhancement of recurrence tumor. The CT number of contrast scan of RT and RF was obviousy different (P < 0.01). CONCLUSION: If a mass lesion appears after radiation therapy in carcinoma of nasopharyx, enhancement of the lesion in CT scan is an important criterion for differential diagnosis.