中文摘要：

目的探讨^18F-FDGPET／CT在鼻咽癌患者颈部淋巴结转移分期中的作用。方法按前瞻性设计研究方案，纳入2009年3月至2010年11月病理确诊为鼻咽癌的初治患者62例，其中男48例，女14例，中位年龄43岁。患者放疗前1周内行cT或MRI检查并进行AJCC分期，然后行^18F—FDGPET／CT检查后再次分期。以治疗后随访6个月以上结果为标准，评价2种检查方法进行N分期的准确性。分析PET／CTN分期对治疗方案的影响，并计算Kappa值，进行一致性检验，率的比较采用，检验。结果62例患者中，N09例，N，16例，N：24例，N，13例。^18F—FDGPET／CTN分期准确性为96．8％（60／62），与实际N分期一致性检验Kappa值为0．955；CT或MRIN分期准确性为72．7％（45／62），Kappa值为0．607。30．6％（19／62）患者PET／CT与CT或MRIN分期不一致，随访证实PET／CT正确改变了27．4％（17／62）患者的N分期；其中1例从N0提高至N2，由根治性放疗改为放化疗综合治疗，另16例改变了转移淋巴结GTV的勾画和照射剂量。PET／CT咽后淋巴结检出率为54．8％（34／62），其灵敏度、特异性和准确性分别为80．0％（20／25）、94．4％（17／18）和86．O％（37／43）。比较43例同时有MRI和PET／CT检查结果的患者资料，两者对咽后淋巴结的检出率分别为60．5％（26／43）和55．8％（24／43），差异无统计学意义（x^2=2．000，P〉0．05）。结论^18F—FDGPET／CT较常规CT或MRI对鼻咽癌N分期的准确性高，且能较好地显示咽后淋巴结，在定性较小淋巴结方面有一定优势。

英文摘要：

Objective To investigate the value of is F-FDG PET/CT in N staging nasopharyngeal carcinoma （NPC） patients compared with CT or MRI. Methods Sixty-two patients （48 males, 14 fe- males, median age 43 y） with NPC confirmed by biopsy were enrolled into this prospective study. All pa- tients underwent CT or MRI as well as is F-FDG PET/CT imaging 1 week before the radiotherapy and staging was based on AJCC 6th edition. The accuracies of the two imaging methods for N staging were evaluated by follow-up clinical resuhs （≥6 months）. Kappa andx2 tests were used to analyze the usefulness of ISF-FDG PET/CT imaging for N staging. Results All of the 62 patients （ No = 9, N1 = 16, N2 = 24, N3= 13 ） un- derwent imaging. In this patient-based analysis, the accuracy of ^18F-FDG PET/CT imaging for N staging was 96.8% （60/62） and Kappa was 0. 955, which were 72.7% （45/62） and 0. 607 for CT or MRI. 30. 6% （19/62） patients had discrepant results of N staging in PET/CT and CT or MRI. 27.4% （17/62） patients underwent changes in their N staging by PET/CT correctly. Of note, one patient＇s stage changed from No to N2 （radiotherapy to chemoradiotherapy） and another 16 patients had changes in the exposure do- ses for drawing GTV. The positive rate of PET/CT for retropharyngeal lymph node detection was 54.8% （34/62）, and the sensitivity, specificity and accuracy were 80.0% （20/25）, 94.4% （17/18） and 86. 0% （37/43）. By comparing 43 patients that underwent MRI and PET/CT imaging, results were com- parative in nodal detection： 60, 5% （ 26/43 ） in MRI vs 55.8% （24/43） in PET/CT （X2 = 2. 000, P 〉 0. 05 ）. Conclusions is F-FDG PET/CT imaging has higher accuracy for N staging in NPC than CT or MRI. It could also be more sensitive to retropharyngeal lymphadenopathy especially for small lymph nodes.