Kubota K, Ishiwata K, Kubota R, Yamada S, Takahashi J, Abe Y, Fukuda H, Ido T
Department of Nuclear Medicine and Radiology, Tohoku University, Sendai, Japan.
J Nucl Med. 1996 Feb;37(2):320-5.
L-[methyl-11C]methionine (11C-Met) is a useful tracer for tumor imaging with PET. The drawbacks include a short half-life and high physiological accumulation in abdominal organs. To overcome these shortfalls, the feasible use of [18F]fluorophenylalanine (18F-Phe), which shares the same amino acid transport system with Met, for tumor imaging was examined.
The time course of tissue distribution of 18F-Phe and the tumor uptake response to radiotherapy were compared with 14C-Met and [3H] thymidine (3H-Thd) in the rat AH109A tumor model. Intratumoral distribution of 18F-Phe was compared with 14C-Met and 14C-Thd using double-tracer macroautoradiography (ARG). We also evaluated whole-body ARG.
Tumor uptake of 18F-Phe peaked at 60 min postinjection and was higher than that of the liver, intestine and kidney but lower than the pancreas. Tumor uptake of 18F-Phe was similar to that of 14C-Met. Tumor-to-blood and tumor-to-muscle ratios were higher in 14C-Met compared with that of 18F-Phe because of the rapid blood clearance of 14C-Met. With whole-body ARG, the tumor was clearly visualized with high contrast. Radiotherapeutic response of tumor uptake of 18F-Phe was as rapid as that with 14C-Met and with 3H-Thd. Intratumoral distribution of 18F-Phe and 14C-Met were identical, and 18F-Phe and 14C-Thd were similar.
Fluorine-18-Phe seems to be a potentially useful amino acid tracer for tumor imaging with a longer half-life than 11C, with higher tumor contrast in the abdomen than Met and a similar sensitive response to radiotherapy.
L-[甲基-11C]蛋氨酸（11C-Met）是一种用于正电子发射断层扫描（PET）肿瘤成像的有用示踪剂。其缺点包括半衰期短以及在腹部器官中的生理性摄取高。为克服这些不足，研究了与蛋氨酸共享相同氨基酸转运系统的[18F]氟苯丙氨酸（18F-Phe）用于肿瘤成像的可行性。
在大鼠AH109A肿瘤模型中，将18F-Phe的组织分布时间进程以及肿瘤对放疗的摄取反应与14C-Met和[3H]胸腺嘧啶核苷（3H-Thd）进行比较。使用双示踪剂宏观放射自显影术（ARG）比较18F-Phe与14C-Met和14C-Thd在肿瘤内的分布。我们还评估了全身ARG。
18F-Phe的肿瘤摄取在注射后60分钟达到峰值，高于肝脏、肠道和肾脏，但低于胰腺。18F-Phe的肿瘤摄取与14C-Met相似。由于14C-Met的血液清除迅速，14C-Met的肿瘤与血液和肿瘤与肌肉的比率高于18F-Phe。通过全身ARG，肿瘤以高对比度清晰可见。18F-Phe的肿瘤摄取对放疗的反应与14C-Met和3H-Thd一样迅速。18F-Phe和14C-Met在肿瘤内的分布相同，18F-Phe和14C-Thd相似。
氟-18-苯丙氨酸似乎是一种潜在有用的氨基酸示踪剂，用于肿瘤成像，其半衰期比11C长，在腹部的肿瘤对比度高于蛋氨酸，并且对放疗的反应敏感性相似。
