Dual-phase 18F-FDG PET in Peripheral Nerve Schwannoma: Incidental Findings in an Asymptomatic Individual for Cancer Screening

神經鞘瘤之雙相氟－18-FDG PET造影：無症狀患者於癌症篩檢之偶然發現

10.6332/ANMS.1804.007

吳明哲(Ming-Che Wu)；林谷鴻(Ku-Hung Lin)；張雯燕(Wen-Yen Chang)；杜高瑩(Kao-Yin Tu)

氟－18-氟化去氣葡萄糖 ； 正子斷層掃描／電腦斷層掃描 ； 神經鞘瘤 ； FDG ； PET/CT ； schwannoma

核子醫學雜誌

18卷4期（2005 / 12 / 01）

235 - 240

英文

一位54歲女性在健康檢查時接受氟－18-氟化去氧葡萄糖(18F-fluorodeoxyglucose, FDG)正子斷層掃描(Positron Emission Tomography PET)癌症篩檢，於注射FDG後45分鐘造影所得影像顯示在右側大腿軟組織有異常之FDG攝取，且延後三小時再次造影時依然明顯可見，雖然其標準攝取值(SUV)已比第一次造影時略爲降低，不過仍然高達3.59，故建議患者做進一步處置。隨後開刀切除結果證實爲一良性之神經鞘瘤(schwannoma)。本病例於兩次造影間標準攝取值之變化與文獻上之報告不盡相同，顯示神經鞘瘤對於氟－18-氟化去氧葡萄糖攝取之強度範圍與變化差異相當大，不足以藉此區分其良惡屬性。此外因爲使用正子斷層掃描／電腦斷層掃描(positron emission tomography/computed tomography, PET/CT)而得以藉由電腦斷層掃描之影像精確定位氟－18-氟化去氧葡萄糖攝取區之相關位置，使得正子斷層掃描報告之參考價值增加，並因此簡化隨後之處置程序與加速處置之速度，對患者應屬有益。爲謹慎起見，做氟－18-氟化去氧葡萄糖正子斷層掃描癌症篩檢時值得考慮將下肢包含在造影範圍內。

A 54-year-old female had 18F-FDG PET for cancer screening during health examination. The early PET images showed abnormal soft tissue uptake in the right thigh while the delayed images showed persistent uptake in the same area. Though the SUV on the delayed images is slightly lower than that of the early images, it is still as high as 3.59, so further workup of the lesion is recommended. The lesion was subsequently excised and proved to be a schwannoma. The change of SUV between the early and delayed images is different from that has been reported in literature and may reflect a wide range variation of FDG uptake that cannot be used to reliably differentiate benign from malignant lesions. With the addition of a concurrent CT scan in a PET/CT scanner, we were able to precisely locate the lesion hence made the PET report more valuable and would likely benefit the patient by saving additional imaging and correlation and facilitate further management. For cancer screening we suggested a more prudent practice by including the lower extremities in the scanning field.