螺旋CT灌注成像在鼻咽癌放疗后局部复发诊断及定量分析中的应用

Application of Spiral Computed Tomography Perfusion Imaging in the Diagnosis and Quantitative Analysis of Local Recurrence of Nasopharyngeal Carcinoma after Radiotherapy

目的探讨螺旋CT灌注成像在鼻咽癌放疗后局部复发诊断及定量分析中的应用价值。方法选取2013年1月~2015年1月于本院行鼻咽癌放疗的患者96例,根据治疗后鼻咽镜病理活检结果将患者分为复发组（n=46）、放疗后改变组（n=32）及无改变组（n=18）,对所有患者进行螺旋CT灌注成像检查,比较3组患者的CT灌注成像参数,主要包括血容量（BV）、血流量（BF）、表面通透性（PS）、平均通过时间（MTT）,并根据ROC曲线分析BF、PS数值对诊断鼻咽癌放疗后局部复发的最佳临界值。结果 3组患者CT灌注成像参数比较结果显示,BF、BV、PS数值存在显著差异（P〈0.05）;复发组与放疗后改变组的MTT指标比较无显著差异（P〉0.05）,与无改变组比较存在显著差异（P〈0.05）;BF、BV、PS的ROC曲线面积分别为0.899、0.935、0.778,BF、BV、PS最佳临界值分别为335.49 m L/100 g·min、10.20 m L/100 g、17.35 m L/100 g·min,灵敏度分别为93.5%、96.8%、82.0%,特异度分别为76.5%、82.4%、60.8%。结论采用螺旋CT灌注成像诊断鼻咽癌放疗后局部复发准确率较高,可根据局部组织灌注参数进行定量或半定量分析,对指导临床治疗及提高患者生存率具有重要意义。

Objective To investigate the application value of computed tomography（CT） perfusion imaging in the diagnosis and quantitative analysis of local recurrence of nasopharyngeal carcinoma after radiotherapy. Methods 96 cases of nasopharyngeal carcinoma treated with radiotherapy from January 2013 to January 2015 were chosen as the research objects. Based on nasopharyngoscopy biopsy results, the patients were divided into relapse group（n=46）, change-after-radiotherapy group（n=32）, and no-change group（n=18）. All patients underwent spiral CT perfusion imaging. CT perfusion imaging parameters of the three groups of patients were compared, including blood volume（BV）, blood flow（BF）, permeability surface（PS）, and mean transit time（MTT）. In accordance with ROC curve, the research analyzed the optimal critical value of BF and PS in the diagnosis of local recurrence of nasopharyngeal carcinoma after radiotherapy. Results The comparison of the CT perfusion parameters of the three groups indicated that there was statistically significant difference existing in BF, BV, and PS value（P0.05）. There was no statistically significant difference in the MTT index between the relapse group and change-after-radiotherapy group（P0.05）. Yet there was significant difference between the relapse group and the no-change group（P0.05）. ROC curve area of the BF, BV, and PS was 0.899, 0.935, and 0.778 respectively. The optimal critical value of BF, BV, and PS was 335.49 m L / 100 g·min, 10.20 m L/100 g, and 17.35 m L/100 g·min respectively. The sensitivity was 93.5%, 96.8% and 82.0% respectively. The specificity was 76.5%, 82.4% and 60.8% respectively. Conclusion The application of spiral CT perfusion imaging increased diagnostic accuracy of local recurrence of nasopharyngeal carcinoma after radiotherapy, which can be quantitatively or semi-quantitatively analyzed based on local tissue perfusion parameters and was of great significance in the guidance of clinical treatment and thus increase the survival rate of patients.