Antenor-Dorsey Jo Ann V, Laforest Richard, Moerlein Stephen M, Videen Tom O, Perlmutter Joel S
Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Eur J Nucl Med Mol Imaging. 2008 Apr;35(4):771-8. doi: 10.1007/s00259-007-0644-6. Epub 2007 Dec 11.
N-([(11)C]methyl)benperidol ([(11)C]NMB) can be used for positron emission tomography (PET) measurements of D(2)-like dopamine receptor binding in vivo. We report the absorbed radiation dosimetry of i.v.-administered (11)C-NMB, a critical step before applying this radioligand to imaging studies in humans.
Whole-body PET imaging with a CTI/Siemens ECAT 953B scanner was done in a male and a female baboon. After i.v. injection of 444-1221 MBq of (11)C-NMB, sequential images taken from the head to the pelvis were collected for 3 h. Volumes of interest (VOIs) were identified that entirely encompassed small organs (whole brain, striatum, eyes, and myocardium). Large organs (liver, lungs, kidneys, lower large intestine, and urinary bladder) were sampled by drawing representative regions within the organ volume. Time-activity curves for each VOI were extracted from the PET, and organ residence times were calculated by analytical integration of a multi-exponential fit of the time-activity curves. Human radiation doses were estimated using OLINDA/EXM 1.0 and the standard human model.
Highest retention was observed in the blood and liver, each with total residence times of 1.5 min. The highest absorbed radiation doses were to the heart (10.5 μGy/MBq) [DOSAGE ERROR CORRECTED] and kidney (9.19 μGy/MBq), [DOSAGE ERROR CORRECTED] making these the critical organs for [(11)C]NMB. A heart absorption of 50 mGy would result from an injected dose of 4,762 MBq [(11)C]NMB.
Thus, this study suggests that up to 4,762 MBq of [(11)C]NMB can be safely administered to human subjects for PET studies. Total body dose and effective dose for [(11)C]NMB are 2.82 μGy/MBq [DOSAGE ERROR CORRECTED] and 3.7 mSv/kBq, respectively.
N-([(11)C]甲基)苯哌利多([(11)C]NMB)可用于体内D(2)样多巴胺受体结合的正电子发射断层扫描(PET)测量。我们报告静脉注射(11)C-NMB的吸收辐射剂量测定，这是将这种放射性配体应用于人体成像研究之前的关键步骤。
使用CTI/西门子ECAT 953B扫描仪对一只雄性和一只雌性狒狒进行全身PET成像。静脉注射444-1221 MBq的(11)C-NMB后，收集从头部到骨盆的连续图像，持续3小时。确定了完全包含小器官(全脑、纹状体、眼睛和心肌)的感兴趣区(VOI)。通过在器官体积内绘制代表性区域对大器官(肝脏、肺、肾脏、下大肠和膀胱)进行采样。从PET中提取每个VOI的时间-活度曲线，并通过对时间-活度曲线的多指数拟合进行分析积分来计算器官驻留时间。使用OLINDA/EXM 1.0和标准人体模型估计人体辐射剂量。
血液和肝脏中的滞留量最高，总驻留时间均为1.5分钟。心脏(10. μGy/MBq)[剂量错误已校正]和肾脏(9.19 μGy/MBq)[剂量错误已校正]的吸收辐射剂量最高，这使它们成为[(11)C]NMB的关键器官。注射4762 MBq[(11)C]NMB会导致心脏吸收50 mGy。
因此，本研究表明，高达4762 MBq的[(11)C]NMB可安全地给予人体受试者进行PET研究。[(11)C]NMB的全身剂量和有效剂量分别为2.82 μGy/MBq[剂量错误已校正]和3.7 mSv/kBq。
