| 摘要: |
| 目的 探讨鼻咽癌患者放疗后常规MRI表现正常的颞叶脑白质微结构及血流动力学的变化特征。方法 对56例常规MRI表现正常的鼻咽癌患者行全脑弥散张量成像(diffusion tensor imaging,DTI)及颞叶动态磁敏感性对比增强MR灌注成像 (dynamic susceptibility contrast-enhanced perfusion MR imaging, DSCE-MR)检查。以放射治疗前14例患者作为对照组,放射治疗后42例患者按放疗后不同时期分为3组,每组14例:组1(0～6个月)、组2(6～12个月)、组3(＞12个月)。测量放疗前后各组患者颞叶脑白质的部分各向异性分数(FA)及相对血流量(rCBF),采用单因素方差分析比较组间差异。结果 对照组及放疗后各组的FA值分别为0.48±0.04、0.37±0.03、0.42±0.04和0.43±0.03,组间差异有统计学意义(F值为13.897,P<0.01)。进一步两两比较,放疗后各组FA值与放疗前相比均降低(P<0.05或P<0.01),放疗后6～12个月组、放疗后＞12个月组均比放疗后0～6个月组升高(P<0.05或P<0.01)。对照组及放疗后各组rCBF值分别为23.21±3.67、17.56±3.01、18.58±3.48和20.34±2.59,组间差异有统计学意义(F值为8.714,P<0.01),放疗后各组rCBF值均比放疗前降低(P<0.05或P<0.01),放疗后＞12个月组比放疗后0～6个月组升高(P<0.05)。结论 DTI 及DSCE灌注成像可以从微观水平反映放射性脑损伤,可作为其早期动态监测评价的手段；血管损伤参与了早期放射性脑损伤。 |
| 关键词: 鼻咽肿瘤 放射疗法 放射损伤 脑 磁共振成像 |
| DOI：10.3724/SP.J.1008.2013.00650 |
| 投稿时间：2013-01-02修订日期：2013-05-22 |
| 基金项目:国家自然科学基金(81271389),广东省科技计划项目(2011b060200002),广州市科技计划项目(11a52120825). |
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| Microstructural and hemodynamic changes following radiation therapy in nasopharyngeal carcinoma patients |
| FENG Xia,QIU Shi-jun* |
(Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou 510515, Guangdong, China
*Corresponding author.) |
| Abstract: |
| Objective To investigate the microstructural and hemodynamic characteristics of the temporal lobes following radiation therapy in nasopharyngeal carcinoma patients with normal MRI manifestations. Methods Diffusion tensor imaging (DTI) and dynamic susceptibility contrast-enhanced perfusion MR imaging (DSCE-MR) were performed in 56 nasopharyngeal carcinoma patients, including 14 pre-radiotherapy patients (control group) and 42 post-radiotherapy patients; the latter was evenly divided into 3 groups: Group 1 (0-6 months after radiation therapy), Group 2 (6-12 months after radiation therapy), and Group 3 (>12 months after radiation therapy). The fractional anisotropy (FA) and relative cerebral blood flow (rCBF) were calculated in bilateral temporal lobes before and after radiotherapy. One-way analysis of variance (one-way ANOVA) test was used for comparison among groups. Results The FA values of the pre-radiation and three post-radiation groups were 0.48±0.04, 0.37±0.03, 0.42±0.04, and 0.43±0.03, respectively, showing significant difference among groups (F=13.897, P<0.01). Multiple comparisons showed that the FA values in the three post-radiation groups were significantly decreased compared with that in the pre-radiation group (P<0.05 or P<0.01). The FA values in Group 2 and Group 3 were higher than that in Group 1 (P<0.05 or P<0.01). The mean rCBF values of the pre-radiation and the three post-radiation groups were 23.21±3.67, 17.56±3.01, 18.58±3.48, and 20.34±2.59, respectively, showing significant difference among groups (F=8.714,P<0.01). The rCBF values in the three post-radiation groups were significantly decreased compared to that in the pre-radiation group (P<0.05 or P<0.01). And the rCBF value in Group 3 was significantly higher than that in Group 1 (P<0.05). Conclusion DTI and DSCE perfusion MRI can detect micro-injury of brain tissue and can be used for early monitoring and evaluation of radiation-induced injury. Blood vessel injury may have participated in the early radiotherapy-induced brain injury. |
| Key words: nasopharyngeal neoplasms radiotherapy radiation injuries brain magnetic resonance imaging |
