FDG-PET在鼻咽癌诊断、疗效监测及转移灶判定中的临床应用

Clinical utility of FDG-PET in diagnosing and detecting residue/recurrence/metastasis of nasopharyngeal carcinomas

目的:探讨脱氧葡萄糖-正电子发射计算机断层(FDG-PET)在鼻咽癌(NPC)诊断、疗效监测及转移灶判定中的临床价值。方法:41例共53次显像分为2组。组1(9例13次)为无NPC病史而PET提示鼻咽癌。组2(32例40次)为临床确诊NPC,经放化疗后PET用于疗效监测。以标准摄取值(SUV)≥2.0定为葡萄糖代谢增高。将PET所示结果与临床及其它影像资料比较,并对每一病例进行了充分的随访(6～24月)。结果:组1仅2例证实为NPC,余7例均为假阳性。组2中10例治疗后病灶完全消失。与同期和?或随后的CT?MR及随访结果一致,PET预测NPC完全缓解的准确性为100%,PET预测完全缓解的时间至少可达6个月以上。余22例PET共发现11例鼻咽局部残留?复发病灶,40处全身转移灶,综合分析表明,1例残留?复发病灶假阳性,2例转移灶假阳性。患者追加治疗后,1例病灶消失,5例病情改善。结论:PET诊断鼻咽癌,准确性较差。对疗效监测,转移灶判定,PET拥有独特的优势。PET与其它方法综合运用,将大大提高鼻咽癌的临床诊治水平。

Objective:To investigate the diagnostic accuracy of positron emission tomography(PET)with18-fluoro-2-de-oxyglucose (FDG)in nasopharyngeal carcinoma (NPC)and to evaluate its value for monitoring therapeutic effect after treatment in clinically diagnosed NPC.Methods:Total53scans were performed using Siemens ECAT EXACT HR+PET scanner un-der the standardized procedures during the period from Oct.1999to Jan.2002.Forty-one patients were further divided into two groups.Cases in group1(n=9,13scans)had no previous NPC history,7had biopsy of nasopharynx subsequently,the other two had nasopharyngoscope without biopsy.Patients in group2who were clinically diagnosed NPC with pathological evidence.Case of both group1and group2underwent PET for the purpose of evaluation therapeutic effect after radiotherapy or chemotheraphy.Standardized uptake value (SUV)was calculated and SUV≥2.0was used as standard.For further investiga-tion,we had sufficient follow up in every patient.Result:All patients in group1had abnormal radioactivity uptake in the nasopharyx with SUV varying between2.01to8.30(5.16±2.44,mean±standard deviation).Among them,only two were proved to be NPC and all the other cases were false positive by biopsy and at least six months followed up.Based on multi-modality imaging results and follow-up,ten cases in group2got complete remission.The accuracy of PET in judging com-plete remission was100%.The remission period was at least6months.Eleven recurrent?persistent foci and40metastasis in group2were found.One recurrent?persistent focus and two metastasis were proved to be false positive.The accuracy were91%and95%respectively.Additional therapy were given in21cases,one got complete remission and five partially improved.Con clusion:PET did not have much potential in diagnosing NPC.PET could be used as a powerful tool in judging thera-peutic effect,it could accurately estimate complete remission and sensitively differentiate necrotic?persistent?recurrent foci.Also it had unique superiority in finding metastasis by whole body scan.Combined with CT?MR?US,PET could greatly improve pa-tient 's management and ameliorate prognosis.