18F-FDG PET/CT在鼻咽癌诊断及分期中的临床价值

背景与目的:PET/CT能够通过准确显示肿瘤形态、大小及相邻关系从而对鼻咽癌(NPC)进行诊断及分期研究.本研究结合PET/CT、MRI结果及部分颈部小淋巴结病理结果,探讨18SF-FDG PET/CT在鼻咽癌TNM分期中的价值.方法:从2005年9月至2007年3月.选取行PET/CT和MRI检查的鼻咽癌患者68例.PET数据采用2D采集模式,CT扫描电压140 kV,采用自动毫安量跟踪扫描加血管增强的扫描方案,18F-FDG按3.7～5.5 MBq/kg剂量静脉注射.MRI检查采用T1W和T2W成像及T1W增强扫描成像.并对其中10例患者颈部小淋巴结切除和穿刺组织病理检查,进行图像与病理对照.结果:68例鼻咽癌患者所有鼻咽区域的病灶PET/CT均可以清晰显示,MRI和PET/CT显示病灶一致:对于直径≤1 cm的138枚PET/CT示阳性小淋巴结,MRI仅有约28%可作不肯定提示.10例鼻咽癌患者颈部16枚PET/CT显示阳性小淋巴结与病理结果相符14枚,符合率达87.5%.对于颈部肿大淋巴结PET/CT.和MRI均能显示,对部分放疗过程PET/CT示增殖活性明显受抑制的肿大淋巴结,MRI和PET/CT增强扫描可见强化.对于其中8例Ⅳb期鼻咽癌患者肺、骨、肝脏等转移灶,PET/CT全身扫描可清晰显示病灶,而MRI具有较多限制.由于18F-FDG PET/CT检查使其中24例的分期进行调整.结论:18F-FDG-PET/CT扫描采用自动毫安量跟踪扫描加血管增强的扫描方案,充分利用PET/CT信息进行鼻咽癌的临床分期,其结果较MRI全面、可靠.

Role of 18F-FDG PET/CT in diagnosis and staging of nasopharyngeal carcinoma

BACKGROUDING & OBJECTIVE: Because (18)F-FDG PET/CT can display cancer lesion morphology, size and the relatinship of the cancer lesion to adjacent tissues, it is used in the diagnosis and classification of nasopharyngeal carcinoma (NPC). This study was to explore the application value of (18)F-FDG PET/CT in TNM staging by comparing the performance of MRI and PET/CT together with pathological results for some small lymph nodes. METHODS: Sixty-eight pathologically proven NPC patients were selected from Sep.2005 to Mar. 2007 in Sun Yat-sen University Cancer Center. All cases underwent both MRI and (18)F-FDG PET/CT examinations. PET/CT two-dimensional (2D) data were collected. Automatic dose tracking scanning and contrast-enhanced CT scanning were performed. (18)F-FDG was intravenously administrated at a dose of 3.7-5.5 MBq/kg. MRI T1W, T2W and T1W Gd-DTPA enhanced images were obtained. Neck lymph nodes of 10 NPC patients were pathologically examined. RESULTS: Nasopharyneal lesions of all 68 cases were all clearly displayed by both PET/CT and MRI. Among 138 small lymph nodes smaller than 1cm in diameter, which were positively detected by PET/CT, only 28.0% were suggested questionable by MRI scanning. Fourteen out of sixteen (87.5%) positive lymph nodes detected by PET/CT from 10 patients were pathologically confirmed. Both PET/CT and MRI revealed enlarged lymph nodes of the neck. Some lymph nodes whose proliferation was inhibited during radiotherapy suggested by PET/CT were displayed intensified images by contrast-enhanced PET/CT and MRI. Metastases to lung, bone and liver in eight stage IVb patients were clearly displayed by PET/CT, but not by MRI. The stage of 24 patients was adjusted after PET/CT scanning. CONCLUSIONS:(18)F-FDG PET/CT with automatic dose tracking scanning protocol and contrast-enhanced scanning can provide more comprehensive information than MRI in diagnosing and staging NPC.