99 Tcm-MIBI SPECT在原发性鼻咽癌诊断、放疗后残余或复发监测中的应用

目的：评价^99Tc^m-甲氧基异丁基异腈(MIBI)SPECT显像对原发性鼻咽癌的诊断和鼻咽癌放疗后局部残余或复发的鉴别价值。方法：20例经病理检查证实的原发性鼻咽癌患者于治疗前、放疗后3和6个月分别行^99Tc^m-MIBI SPECT显像，与同期CT和(或)MRI结果对照，分别计算肿瘤或正常鼻咽部与头皮的放射性计数比值，作为^99Tc^m-MIBI摄取指数(MUI)。以接受器工作特性(ROC)曲线确定MUI判别阈值。以鼻咽部内镜检查、病理活组织检查及18个月的临床随访资料作为鼻咽癌残余或复发的依据。结果以MUI≥2．15为阳性标准，^99Tc^m-MIBISPECT显像诊断原发性鼻咽癌的灵敏度、特异性和准确性均为95％。以MUI≥1．32为阳性标准，^99Tc^m-MIBI SPECT显像监测鼻咽癌残余或复发的灵敏度为3／4例，特异性93．8％，准确性90．0％。CT和(或)MRI监测鼻咽癌残余或复发的灵敏度为3／4例，特异性81．3％，准确性80．0％。^99Tc^m-MIBISPECT显像与CT和(或)MRI联合鉴别鼻咽癌残余或复发的灵敏度、特异性和准确性分别为2／2例、92．9％和93．8％。结论:^99Tc^m-MIBI SPECT显像对确定鼻咽癌原发灶范围有一定价值；与CT和(或)MRI联合，可提高对放疗后鼻咽癌残余或复发的早期诊断效能。

99 Tcm-MIBI SPECT in detection of primary nasopharyngeal carcinoma and in differentiation of residual or recurrent lesions after radiotherapy

Objective To investigate the diagnostic potential of 99 Tc m-methoxyisobutylisonitrile (MIBI) SPECT in evaluating the extent of primary disease and differentiating residual/recurrent lesions post radiotherapy in patients with nasopharyngeal carcinoma (NPC). Methods Twenty patients with primary NPC histologically confirmed with biopsy underwent repeated 99 Tc m-MIBI SPECT before radiotherapy and at 3 months,6 months after radiotherapy. The scintigraphic findings were compared with that of CT/MRI. Nasopharyngeal-to-scalp ratios were obtained as MIBI uptake index (MUI). The recurrent lesions were judged with biopsy and (or) clinical follow-up which lasted for 18 months after radiotherapy. Receiver operating characteristic analysis was used to defined the cut-off of MUI. Results When MUI 2.15 was used as cut-off,the sensitivity,specificity and accuracy for detecting the primary NPC were all 95%. The optimum cut-off of 1.32 of MUI was defined with sensitivity of 3/4,specificity of 93.8%,and accuracy of 90.0% for differentiating residual/recurrent lesions from the benign process post radiotherapy,while CT/MRI evaluations showed sensitivity of 3/4,specificity of 81.3%,and accuracy of 80.0%. A combination of CT/MRI and 99 Tc m-MIBI SPECT for 16 NPC patients with congruent results showed sensitivity of 2/2,specificity of 92.9%,and accuracy of 93.8% for differentiating residual/recurrent NPC from benign lesions. Conclusions 99 Tc m-MIBI SPECT may play a role in detecting primary NPC. The combination of CT/MRI and 99 Tc m-MIBI SPECT may give more accurate diagnosis and differentiation in distinguishing residual/recurrent lesions in the post radiotherapy follow-up.