Debebe Senait Aknaw, Goryawala Mohammed, Adjouadi Malek, Mcgoron Anthony J, Güleç Seza A
Florida International University, Herbert Wertheim College of Medicine, Department of Surgical Oncology, Miami, USA Phone: (001) (786) 6930821 E-mail:
Mol Imaging Radionucl Ther. 2016 Feb 5;25(1):32-8. doi: 10.4274/mirt.24008.
This phase-I imaging study examined the imaging characteristic of 3'-deoxy-3'-(18F)-fluorothymidine (18F-FLT) positron emission tomography (PET) in patients with pancreatic cancer and comparisons were made with (18F)-fluorodeoxyglucose (18F-FDG). The ultimate aim was to develop a molecular imaging tool that could better define the biologic characteristics of pancreas cancer, and to identify the patients who could potentially benefit from surgical resection who were deemed inoperable by conventional means of staging.
Six patients with newly diagnosed pancreatic cancer underwent a combined FLT and FDG computed tomography (CT) PET/CT imaging protocol. The FLT PET/CT scan was performed within 1 week of FDG PET/CT imaging. Tumor uptake of a tracer was determined and compared using various techniques; statistical thresholding (z score=2.5), and fixed standardized uptake value (SUV) thresholds of 1.4 and 2.5, and applying a threshold of 40% of maximum SUV (SUVmax) and mean SUV (SUVmean). The correlation of functional tumor volumes (FTV) between 18F-FDG and 18F-FLT was assessed using linear regression analysis.
It was found that there is a correlation in FTV due to metabolic and proliferation activity when using a threshold of SUV 2.5 for FDG and 1.4 for FLT (r=0.698, p=ns), but a better correlation was obtained when using SUV of 2.5 for both tracers (r=0.698, p=ns). The z score thresholding (z=2.5) method showed lower correlation between the FTVs (r=0.698, p=ns) of FDG and FLT PET.
Different tumor segmentation techniques yielded varying degrees of correlation in FTV between FLT and FDG-PET images. FLT imaging may have a different meaning in determining tumor biology and prognosis.
本I期成像研究检测了3'-脱氧-3'-(18F)-氟胸苷（18F-FLT）正电子发射断层扫描（PET）在胰腺癌患者中的成像特征，并与(18F)-氟脱氧葡萄糖（18F-FDG）进行了比较。最终目的是开发一种分子成像工具，能够更好地界定胰腺癌的生物学特征，并识别那些通过传统分期方法被认为无法手术切除但可能从手术切除中获益的患者。
6例新诊断的胰腺癌患者接受了FLT和FDG联合计算机断层扫描（CT）PET/CT成像方案。FLT PET/CT扫描在FDG PET/CT成像后1周内进行。使用各种技术确定并比较示踪剂的肿瘤摄取情况；统计阈值化（z评分=2.5）、固定标准化摄取值（SUV）阈值1.4和2.5，以及应用最大SUV（SUVmax）和平均SUV（SUVmean）的40%作为阈值。使用线性回归分析评估18F-FDG和18F-FLT之间功能肿瘤体积（FTV）的相关性。
发现当使用FDG的SUV阈值为2.5和FLT的SUV阈值为1.4时，由于代谢和增殖活性，FTV之间存在相关性（r=0.698，p=无统计学意义），但当两种示踪剂均使用SUV 2.5时，相关性更好（r=0.698，p=无统计学意义）。z评分阈值化（z=2.5）方法显示FDG和FLT PET的FTV之间相关性较低（r=0.698，p=无统计学意义）。
不同的肿瘤分割技术在FLT和FDG-PET图像的FTV之间产生了不同程度的相关性。FLT成像在确定肿瘤生物学和预后方面可能具有不同的意义。
