PET/CT与MRI在鼻咽癌淋巴结转移诊断和N分期中的比较研究

目的 比较PET／CT与MRI在鼻咽癌淋巴结转移诊断和N分期中的作用。方法116例鼻咽癌患者于治疗前行PET／CT和MRI检查。依据随访结果比较PET／CT和MRI在淋巴结转移诊断和N分期中的作用。结果116例患者的614个淋巴结的随访结果显示,阳性340个,阴性274个。PET／CT诊断转移淋巴结的敏感性、特异性及准确性分别为93．2％、98．2％和95．4％,而MRI分别为88．8％、91．2％和89．9％,两者各指标比较,差异有统计学意义（P〈0．05）。按1992年福州分期,109例（94．0％）的PET／CT分期正确,103例（88．8％）的MRI分期正确;按UICC分期,108例（93．1％）的PET／CT分期正确,100例（86．2％）的MRI分期正确。结论PET／CT判断鼻咽癌淋巴结转移和N分期较MRI准确,但对炎性增生、大面积坏死淋巴结,或直径小于PET空间分辨率的转移淋巴结应警惕其假阳性和假阴性判断。

Comparison between PET/CT and MRI in diagnosing lymph node metastasis and N staging of nasopharyngeal carcinoma

Objective To compare the clinical significance of PET/CT and MRI in diagnosing lymph node metastatsis and N staging of nasopharyngeal carcinoma ( NPC). Methods 116 NPC patients had undergone PET/CT and MRI before therapy. The findings of PET/CT and MRI in diagnosing lymph node metastatsis and N staging were compared according to the results of follow-up. Results A total of 614 lymph nodes in 116 patients were analyzed. 340 positive nodes and 274 negative nodes interpreted by image findings were verified during follow-up. The sensitivity, specificity and accuracy of PET/CT in diagnosing node metastatsis was 93. 2% , 98. 2% and 95. 4% , while that of MRI was 88. 8% , 91. 2% and 89. 9% , respectively, with statistically significant difference in each between PET/CT and MRI (P<0.05). Based on Fuzhou Staging System, 109 patients (94. 0%) were correctly staged by PET/CT, and 103 patients (88. 8% ) by MRI, while according to UICC Staging System, 108 patients (93. 1% ) were correctly staged by PET/CT, and 100 patients (86.2% ) by MRI. Conclusion PET/CT is superior to MRI in diagnosing lymph node metastatsis and N staging of nasopharyngeal carcinoma. The false-positive and false-negative assessment based on PET-CT scan findings may be caused by; ( 1) inflammatory hyperplastic node; ( 2 ) node with large areas of necrosis; (3) node in diameter less than spatial resolution limitation of PET.