磁共振灌注成像在鼻咽癌放射治疗中的应用

Application of Magnetic Resonance Perfusion Weighted Imaging in Nasopharyngeal Carcinoma Radiotherapy

目的探讨磁共振灌注成像(MR-PWI)参数作为评价鼻咽癌放疗敏感性指标的可行性,及其在鼻咽癌放射治疗后随访中的价值。方法收集64例经组织病理学证实的鼻咽癌患者临床资料,收治前均未有放、化疗史,放射治疗前1天及放疗4周后各行1次常规MRI及MR-PWI检查,对比分析放疗前后鼻咽部肿瘤的大小、灌注特点及灌注参数的变化。结果在MR-PWI图像上,放疗前鼻咽癌肿块主要表现为高灌注,其显示的高灌注区域最大层面面积要小于放疗前增强T1WI脂肪抑制序列显示面积(P<0.05);40 Gy剂量放射治疗后,敏感组高灌注区域明显下降,其下降面积要大于增强T1WI脂肪抑制序列显示面积(P<0.05);肿瘤放疗后坏死或纤维化表现为BV下降,而复发表现为BV升高(P<0.05)。结论常规MRI检查结合MR-PWI成像,可以更准确的反应鼻咽癌放疗前后的生物学变化;灌注图像及其参数在作为评价鼻咽癌放疗敏感性的指标,及鉴别肿瘤放疗后复发与坏死或纤维化中具有重要的参考价值。

Objective To study the application of magnetic resonance perfusion weighted imaging（ MR-PWI） parameters as the feasibility of nasopharyngeal carcinoma radiotherapy sensitivity evaluation index,and its value in the follow-up after radiotherapy for nasopharyngeal carcinoma（ NPC）. Methods 64 cases of patients with nasopharyngeal carcinoma（ NPC）,which were confirmed by histopathology,history of treated before are not radiotherapy or chemotherapy. The day before radiotherapy and radiotherapy after four weeks in a routine MRI and MR PWI inspection,comparison and analysis,the size of the tumor before and after radiotherapy of nasopharyngeal perfusion characteristics and changes of perfusion parameters. Result In the image of MR-PWI,before radiotherapy of nasopharyngeal mass mainly for high perfusion,it is high perfusion area bigger level display area is smaller than before radiotherapy enhanced T1 WI fat suppression sequence（ P〈 0. 05）; After 40 Gy dose radiotherapy,high sensitive group significantly decreased perfusion area,high sensitive group significantly decreased perfusion area,its decline in area than enhanced T1 WI fat suppression sequence,（ P〈 0. 05）. Conclusion Combined with perfusion imaging,can be more accurate reflection of biological changes after radiotherapy of nasopharyngeal carcinoma; perfusion image and its parameters in as evaluation index of nasopharyngeal carcinoma radiotherapy sensitivity,and the identification of tumor recurrence after radiotherapy and necrosis or fibrosis has important reference value.