Comparison of Fasting With Low-carbohydrate High-fat Diet for the Standardized Uptake Values of ^(18)F-FDG in Human Tissues and Different Cancers

比較禁食與低碳水化合物高脂飲食對人體組織及不同腫瘤去氧葡萄糖標準攝取值的差異

邱宇莉(Yu-Li Chiu) ； 胡瑨(Chin Hu) ； 王雅君(Ya-Chun Wang) ； 石娉雯(Ping-Wen Shih) ； 劉文山(Wen-Shan Liu) ； 彭南靖(Nan-Jing Peng)

《核子醫學暨分子影像雜誌》 33卷3期 (2020/09) Pp. 168-177

https://doi.org/10.6332/ANMMI.202009_33(3).0004

摘要

Background: Low-carbohydrate high-fat diet (LCHFD) has been reported to suppress myocardial ^(18)F-fluorodeoxyglucose (FDG) uptake and decrease the uptake of ^(18)F-FDG in hypermetabolic brown adipose tissue, and might decrease false-positive findings on oncologic ^(18)F-FDG positron emission tomography (PET) scans. This study was proposed in order to compare fasting with LCHFD for the distribution of FDG in the human body and cancers of the same individuals and evaluate the availability of LCHFD to be an alternative method of fasting in the ^(18)F-FDG PET/ computed tomography (CT) study. Methods: We recruited asymptomatic volunteers and patients with diabetes and primary cancer to perform fasting and LCHFD PET/CT. Both PET/CT scans were performed 24 hours apart. The LCHFD and fasting protocols were standardized. Blood tests before FDG injection were recorded. The maximal standardized uptake value (SUVmax) of the organs on PET/CT was measured including the brain, the myocardium, the mediastinum, the liver, the lungs, the muscles, and the tumors. Means and the standard deviation was determined, and a site-to-site comparison using the paired Student's t-test was performed to assess p values. Results: Eighteen asymptomatic volunteers, 9 diabetics and 11 patients with cancers were included. In all of the 38 subjects, the blood tests showed no significant difference in blood glucose and fatty acid on LCHFD and fasting protocols. The SUVmax of the organs on LCHFD showed decreased in the brain, the myocardium, the liver, the mediastinum, and the lungs, but increased in muscles as compared to those on fasting protocol. The difference was significant only in the mediastinum (p = 0.04), especially diabetics (p = 0.039). In the 11 patients with cancers, there was no significant difference in the SUVmax of the tumors between PET/CTs of fasting and LCHFD protocols either using patient or lesion-based statistics. Conclusions: LCHFD could suppress mediastinal ^(18)F-FDG uptake, and provided better image quality. Since it does not influence the FDG uptake in cancers, LCHFD might be an alternative method of fasting in the ^(18)F-FDG PET/CT study.

關鍵字

low-carbohydrate high-fat diet ； FDG ； PET/CT ； standardized uptake values (SUV)

並列摘要

背景：研究顯示低碳水化合物高脂飲食（Low-carbohydrate high-fat diet, LCHFD）可抑制心肌氟-18去氧葡萄糖的攝取及降低棕色脂肪組織氟-18去氧葡萄糖的攝取，因而減低癌症造影時偽陽性的結果。本研究的目的為比較同一人於禁食（fasting）及LCHFD檢查時，氟-18去氧葡萄糖於身體各器官及各種癌症腫瘤攝取的差異性，藉此評估LCHFD取代fasting為常規氟-18去氧葡萄糖正子造影檢查的準備程序的可行性。方法：本研究徵募無症狀的志願者、糖尿病患者及癌症病患，接受fasting及LCHFD氟-18去氧葡萄糖正子造影檢查，兩次檢查相隔24小時以上。LCHFD及fasting過程均標準化，收集注射氟-18去氧葡萄糖前的抽血數值。正子造影檢查完成後，偵測各器官組織的最大標準攝取值（maximal standardized uptake value, SUVmax），包括腦部、心臟、肝臟、縱隔腔、肺臟及肌肉等，以及癌症病患之癌症腫瘤。以成對Student's t-test做每一處之平均值及標準差的比對，算出統計差異（p值）。結果：共計38例受檢者，包括18例無症狀的健康志願者，11例癌症病例及9例糖尿病患者完成本研究。38例受檢者LCHFD檢查前之血糖及醣化血色素數值較fasting檢查前低，但C-胜鏈胰島素、胰島素及脂肪酸較fasting高。在影像方面，腦部、心臟、肝臟、縱隔腔及肺臟SUVmax在LCHFD較fasting降低，肌肉略增高，但除縱隔腔SUVmax（p=0.04）外，各器官SUVmax均無明顯差異。癌症病例中，以每例病人之主要腫瘤（n=11）及以病灶計算之腫瘤（n=22），SUVmax均無明顯差異（p＜0.05）。結論：LCHFD可降低縱隔腔氟-18去氧葡萄糖的攝取，提供縱隔腔較佳的影像品質。但不影響糖尿病患者之影像品質及癌症病患之腫瘤攝取。LCHFD可成為fasting氟-18去氧葡萄糖正子造影檢查的替代方法。

並列關鍵字

低碳水化合物高脂飲食 ； 氟-18去氧葡萄糖 ； 正子斷層造影檢查 ； 標準攝取值