脑转移瘤放疗疗效的DTI研究

目的探讨弥散张量成像（DTI）多参数定量分析脑转移瘤放疗疗效的临床应用价值。方法 28例脑转移瘤放疗患者,共计44个病灶。患者放疗前、放疗结束当日、放疗后1、3、6月行MRI常规扫描以及DTI检查。选取32个病灶,测量放疗前后不同时期的ADC、FA值。结果放疗后不同时期病灶的ADC值呈逐渐上升趋势。放疗结束当日与放疗前比较,ADC值差异无统计学意义;放疗后1、3、6月分别与放疗前比较ADC值升高,差异均有统计学意义。而FA值变化幅度不大,组间差异无统计学意义。结论放疗后转移瘤ADC值逐渐上升反映放疗的早期疗效较好,而FA值在判断瘤体疗效上价值不大。在放疗早期MRI上未发生改变之前,DTI的ADC值已发生变化,能更好反应其微观病理学改变,在评价早期放疗疗效上比常规MRI检查更优越。

Assessment of radiotherapy effects on metastatic brain tumors with diffusion tensor imaging

Objective To evaluate the clinical application of diffusion tensor magnetic resonance imaging（DTI） in the assessment of radiotherapy effects on metastatic brain tumors.Methods Twenty-eight patients with metastatic brain tumors（44 foci） were enrolled in the study.All patients received pan-brain radiotherapy and followed up for at least 6 months after treatment.Routine MRI examination and DTI were performed to measure ADC,FA value in-focus and periventricle alba of 32 foci before radiotherapy,immediately and 1,3,6 months after radiotherapy.Results Compared with pre-radiotherapy levels,ADC value was significantly rising 1,3,6 months after radiotherapy;while FA value changed very little.Conclusion ADC value measured by DTI may be a more sensitive indicator for pathological change in brain metastatic foci and early effect of radiotherapy than routine MRI examination.