【摘要】 背景与目的:枕骨斜坡是鼻咽癌复发的常见部位之一,因位置深在,周围解剖复杂,很难进行枕骨斜坡部位活检,只能根据临床表现及随访情况作出判断。早期鉴别鼻咽癌放疗后枕骨斜坡纤维化(Radiofibrosis,RF)与复发(RecurrentNPC,RNPC)十分困难。本研究对放疗后纤维化与复发的枕骨斜坡进行动态MRI检查,旨在了解这两种枕骨斜坡的动态增强特点,探讨动态增强MRI技术在鼻咽癌放疗后枕骨斜坡纤维化与复发的鉴别诊断中的价值。方法:将38例经中山大学肿瘤防治中心及第二附属医院放射治疗并随访1～5年的鼻咽癌患者分为2组:鼻咽癌枕骨斜坡放疗后纤维化组22例(RF组)及枕骨斜坡复发组16例(RNPC组)。常规鼻咽部MRI平扫后,行动态增强MRI检查。动态增强后,行常规增强T1WI扫描。应用分析软件,分别得到两组枕骨斜坡、髁突及鼻甲的最大对比增强率(Maximalcontrastenhancementratio,MCER)、到达最大对比增强率的时间(Tmax)及动态早期(40s时)对比增强率(CER40s)。结果:鼻咽癌放疗后枕骨斜坡纤维化,其MCER、CER40s较低,Tmax较长。而枕骨斜坡复发,其MCER、CER40s较高,Tmax较短,与放疗后纤维化斜坡明显不同。分别以枕骨斜坡CER40s≥150%、枕骨斜坡CER40s≥鼻甲CER40S、两者均符合作为诊断鼻咽癌枕骨斜坡复发的标准,枕骨斜坡CER40s≥鼻甲CER40s的敏感性最高(81.3%),而CER40s≥150%并且枕骨斜坡CER40s≥鼻甲CER40s时,特异性最高(86.4%)。结论:动态增强MRI技术对于鼻咽癌放疗后枕骨斜坡纤维化与复发的鉴别诊断具有重要的价值。当CER40s≥150%并且枕骨斜坡CER40s≥鼻甲CER40s时,提示为鼻咽癌枕骨斜坡复发;当两者不一致时,应首先以枕骨斜坡CER40s≥鼻甲CER40s为标准,结合MCER、Tmax综合分析。更多还原

【Abstract】 BACKGROUND & OBJECTIVE: Basilar clivus is a commonsite of recurrent nasopharyngeal carcinoma (RNPC). Biopsy of the basilarclivus is seldom done because of its deep location and complex anatomicstructure, therefore, early differential diagnosis of radiofibrosis (RF) andRNPC at the basilar clivus is very difficult. This study was designed toinvestigate the characteristics of radiofibrosis and RNPC at the basilar clivuson dynamic enhanced magnetic resonance imaging (DMRI) for differentialdiagnosis. METHODS: A total of 38 NPC patients, treated in Cancer Centerand the Second Affiliated Hospital of Sun Yat-sen University with follow-up of1- 5 years, were divided into 2 groups: 22 in RF group and 16 in RNPC( RNPC at the basilar clivus) group. After conventional plain MRI scan ofnasopharynx, DMRI and conventional contrast enhanced T1-weighted imaging( T1WI) were performed. Maximal contrast enhancement ratio (MCER) , timeto MCER (Tmax), and contrast enhancement ratio at the 40th second of DMRI( CER40s) of basilar clivus, condylar process, and nasal concha weremeasured. RESULTS: The MCER and CER40s of RF at the basilar clivus werelower, and the Tmax was longer than those of RNPC at the basilar clivus.When CER40s ≥150% , CER40s of basilar clivus ≥ CER40s of nasal concha,and the combination of these 2 indexes were respectively set as the DMRIdiagnostic criteria of RNPC at the basilar clivus, the diagnostic sensitivity ofthe second criterion was the highest (81.3%) , and the diagnostic specificityof the third criterion was also the highest (86.4%). CONCLUSIONS: DMRI ishelpful for differential diagnosis of radiofibrosis and RNPC at the basilarclivus. RNPC at the basilar clivus is highly suggested when it meet thecriteria of both CER40s ≥150% and CER40s of basilar clivus ≥ CER40s of nasalconcha. When the 2 criteria are conflictive, the latter is more accurate,MCER and Tmax of the basilar clivus should be took into consideration.更多还原