单发肺类癌的18F-FDG PET/CT表现

18F-FDG PET/CT image manifestations of solitary lung carcinoid tumor

目的探讨肺类癌的18F-氟脱氧葡萄糖(FDG)PET/CT显像的影像学特点。方法回顾性分析2009年3月至2018年8月于南京医科大学第一附属医院经病理证实的16例肺类癌患者的18F-FDG PET/CT影像学表现,包括病灶的位置、形态特征、代谢情况及全身转移情况。16例肺类癌患者包括男性6例、女性10例,年龄43~78岁,中位年龄65岁;典型类癌(AC)5例,非典型类癌(TC)11例。采用t检验比较TC与AC两组病灶的最大标准化摄取值(SUVmax)的差异。结果16例肺类癌均为单发,病灶密度均匀,均无坏死囊变和钙化,CT值为(38±7)HU.9例中央型肺类癌中,8例可见"冰山征",5例伴阻塞性肺炎;7例周围型肺类癌均未见阻塞性肺炎。1例AC患者可见多发骨转移,其余15例均未发现淋巴结及远处转移。16例肺类癌的SUVmax为4.00±1.64,最大径为(2.59±1.00)cm,SUVmax与最大径无相关性(r=0.238,P=0.375)。TC的SUVmax为3.32±1.17,AC的SUVmax为5.49±1.60,二者比较差异有统计学意义(t=-3.083,P=0.008)。结论肺类癌18F-FDG PET/CT多表现为类圆形软组织结节或肿块,对18F-FDG的摄取轻度增高。

Objective To analyze the image features of lung carcinoid tumor during 18F-fluorodeoxyglucose(18F-FDG)PET/CT.Methods The 18F-FDG PET/CT image manifestations of 16 patients with lung carcinoma,as confirmed by pathology,who underwent 18F-FDG PET/CT pretreatment from March 2009 to August 2018 were reviewed.The location,shape,whole-body metastasis,and metabolism of the lesions were observed.The 16 cases included 6 males and 10 females aged 43-78 years old,with a median age of 65 years.The cases included 5 typical carcinoma(TC)and 11 atypical carcinoma(AC).The statistical difference in maximum standardized uptake value(SUVmax)between TC and AC was investigated using t test.Results All the 16 cases were solitary and showed uniform lesion density and no necrotic cystic degeneration nor calcification.The CT value was(38±7)HU.Nine and seven cases were central and peripheral types,respectively.Out of the nine central type cases,eight showed iceberg lesions,and five presented obstructive pneumonia.However,obstructive pneumonia was absent in the seven cases of peripheral pulmonary carcinoma.In total,1 case exhibited multiple bone metastases through PET/CT,whereas the remaining 15 cases revealed no lymph node nor distant metastasis.The tumor size and SUVmax were(2.59±1.00)cm and 4.00±1.64,respectively.No correlation was found between the SUVmax and tumor size(r=0.238,P=0.375).The SUVmax of TC and AC reached 3.32±1.17 and 5.49±1.60,respectively,with significant difference between two groups(t=-3.083,P=0.008).Conclusions The 18F-FDG PET/CT manifestations of most lung carcinoid tumors were round soft tissue nodules or masses with mild 18F-FDG uptake.Iceberg sign was detected in most central lung carcinomas,whereas necrotic cystic degeneration and calcification were rare.