Department of Nuclear Medicine, Okmeydani Training and Research Hospital, Istanbul, Turkey.
Eur J Nucl Med Mol Imaging. 2010 May;37(5):1011-7. doi: 10.1007/s00259-009-1330-7. Epub 2010 Jan 27.
This study was done to determine whether interruption of metformin before (18)F-FDG PET/CT imaging could prevent the increased (18)F-FDG uptake in the intestine caused by this drug.
Included in the study were 41 patients with known type 2 diabetes mellitus who were referred to our department for evaluation of various neoplastic diseases. Patients underwent two (18)F-FDG PET/CT scans, the first while they were on metformin and the second after they had stopped metformin. They stopped metformin and did not take any other oral antidiabetic medication starting 3 days before the second study and their blood glucose level was regulated with insulin when necessary to keep it within the range 5.55-8.33 mmol/l. FDG uptake was graded visually according to a four-point scale and semiquantitatively by recording the maximum standardized uptake value (SUVmax) in different bowel segments. A paired-samples t-test method was used to determine whether there was a significant difference between SUVmax measurements and visual analysis scores of the metabolic activity of the bowel in the PET/CT scans before and after stopping metformin.
Diffuse and intense (18)F-FDG uptake was observed in bowel segments of patients, and the activity in the colon was significantly decreased both visually and semiquantitatively in PET/CT scans performed after patients stopped metformin (p<0.05). There was a statistically significant decrease in activity in the small intestine on visual analysis (p<0.05), but semiquantitative measurements did not show a significant decrease in the SUVmax values in the duodenum or jejunum (p>0.05).
Metformin causes an increase in (18)F-FDG uptake in the bowel and stopping metformin before PET/CT study significantly decreased this unwanted uptake, especially in the colon, facilitating the interpretation of images obtained from the abdomen and preventing the obliteration of lesions.
本研究旨在确定在（18）F-FDG PET/CT 成像前中断二甲双胍是否可以预防该药物引起的肠道（18）F-FDG 摄取增加。
本研究纳入了 41 例已知患有 2 型糖尿病的患者，他们因各种肿瘤疾病就诊于我院。患者接受了两次（18）F-FDG PET/CT 扫描，第一次扫描时正在服用二甲双胍，第二次扫描时已经停止服用。他们在第二次研究前 3 天停止服用二甲双胍和任何其他口服降糖药物，必要时使用胰岛素调节血糖水平，使其保持在 5.55-8.33mmol/L 范围内。根据 4 分制对 FDG 摄取进行视觉分级，并通过记录不同肠段的最大标准化摄取值（SUVmax）进行半定量分析。采用配对样本 t 检验方法，确定在停止服用二甲双胍前后的 PET/CT 扫描中，肠道代谢活性的 SUVmax 测量值和视觉分析评分之间是否存在显著差异。
患者的肠段可见弥漫性和强烈的（18）F-FDG 摄取，停止服用二甲双胍后行 PET/CT 扫描，结肠的活性在视觉和半定量分析上均明显降低（p<0.05）。视觉分析显示小肠活性有统计学意义的降低（p<0.05），但半定量测量并未显示十二指肠或空肠 SUVmax 值有显著降低（p>0.05）。
二甲双胍会导致肠道（18）F-FDG 摄取增加，在 PET/CT 研究前停止服用二甲双胍可显著减少这种不必要的摄取，尤其是在结肠，有助于解释腹部获得的图像，并防止病变被掩盖。
