Kim Chung Ho, Yoo Ie Ryung, Chung Yong An, Park Young Ha, Kim Sung Hoon, Sohn Hyung Sun, Chung Soo Kyo
Department of Radiology, College of Medicine, The Catholic University of Korea, Kangnam St. Mary's Hospital, 505 Banpodong, Seocho-Gu, Seoul 137-701, South Korea.
Ann Nucl Med. 2009 Feb;23(2):131-6. doi: 10.1007/s12149-008-0218-0. Epub 2009 Feb 19.
In poorly differentiated thyroid cancer originating from thyroid follicular cells, the ability to concentrate iodine is lost. This makes recurrence undetectable by (131)I whole-body scan. In this situation, other radiopharmaceuticals, such as (18)F-fluorodeoxyglucose ((18)F-FDG) and technetium-99m-methoxyisobutylisonitrile ((99m)Tc-MIBI), are used to evaluate recurrence or metastasis. Some reports suggest that (18)F-FDG uptake is increased by thyroid-stimulating hormone (TSH) stimulation. This study aimed to determine the influence of TSH on (18)F-FDG and (99m)Tc-MIBI uptake in human poorly differentiated thyroid cancer cells in vitro.
The cells were stimulated with 1000 muU/ml of recombinant human thyroid-stimulating hormone (rhTSH) for 1 day, 3 days, and 5 days. Each cell was incubated with 0.5 MBq/ml-1 MBq/ml of (18)F-FDG or 0.5 MBq/ml-1 MBq/ml of (99m)Tc-MIBI for 1 h at 37 degrees C. The uptake of each radiopharmaceutical in the cells was quantified as a percent of whole radioactivity per total viable cell number. The quantification of glucose transporter 1, 2, 3 and 4 mRNA expression was measured using RT-PCR.
TSH stimulation increased (18)F-FDG uptake in a time-dependent manner. Following 5 days of rhTSH stimulation, (18)F-FDG uptake was approximately 2.2 times that of the control. The increase in (18)F-FDG uptake following rhTSH stimulation was correlated to the increase in GLUT4 mRNA level. The GLUT1 mRNA level was unchanged. An increased uptake of (99m)Tc-MIBI was observed with a pattern similar to that of (18)F-FDG. The (99m)Tc-MIBI uptake was approximately 1.5 times that of the control 5 days later.
These results suggest that TSH stimulates (18)F-FDG and (99m)Tc-MIBI uptake in poorly differentiated papillary thyroid cancer, and therefore (18)F-FDG-PET or (99m)Tc-MIBI scans under TSH stimulation may be more accurate than under suppression.
在源自甲状腺滤泡细胞的低分化甲状腺癌中，碘摄取能力丧失。这使得（131）I全身扫描无法检测到复发情况。在此种情况下，其他放射性药物，如（18）F - 氟脱氧葡萄糖（（18）F - FDG）和锝 - 99m - 甲氧基异丁基异腈（（99m）Tc - MIBI），被用于评估复发或转移情况。一些报告表明，甲状腺刺激激素（TSH）刺激可增加（18）F - FDG摄取。本研究旨在确定TSH对体外培养的人低分化甲状腺癌细胞中（18）F - FDG和（99m）Tc - MIBI摄取的影响。
用1000μU/ml重组人甲状腺刺激激素（rhTSH）刺激细胞1天、3天和5天。将每个细胞与0.5MBq/ml - 1MBq/ml的（18）F - FDG或0.5MBq/ml - 1MBq/ml的（99m）Tc - MIBI在37℃孵育1小时。将细胞中每种放射性药物的摄取量定量为每总活细胞数的总放射性的百分比。使用逆转录聚合酶链反应（RT - PCR）测量葡萄糖转运蛋白1、2、3和4 mRNA表达的定量。
TSH刺激以时间依赖性方式增加（18）F - FDG摄取。rhTSH刺激5天后，（18）F - FDG摄取量约为对照组的2.2倍。rhTSH刺激后（18）F - FDG摄取的增加与GLUT4 mRNA水平的增加相关。GLUT1 mRNA水平未改变。观察到（99m）Tc - MIBI摄取增加，其模式与（18）F - FDG相似。5天后（99m）Tc - MIBI摄取量约为对照组的1.5倍。
这些结果表明，TSH刺激低分化乳头状甲状腺癌中（18）F - FDG和（99m）Tc - MIBI摄取，因此TSH刺激下的（18）F - FDG - PET或（99m）Tc - MIBI扫描可能比抑制状态下更准确。
