Biokinetics Study of Tc-99m DMSA for Dose Reduction in Pediatric Molecular Imaging
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 24
- 试验地点
- 1
- 主要终点
- Radioactivity in target organs at various time points
研究概览
简要总结
The radiation exposure resulting from medical imaging is a topic of some concern. Nuclear medicine provides potentially life-saving information regarding physiological processes, and is of particular value in children where the rapid and unequivocal diagnosis of pathological concerns is essential for the health of these patients. The overall objective of this investigation is to optimize pediatric patient absorbed dose by keeping it as low as possible while maintaining excellent diagnostic quality of nuclear medicine images. This is particularly important since children are at increased risk due to the enhanced radiosensitivity of their tissues and the longer time-period over which radiation effects may manifest. Current dosimetric estimations in children are based on either animal biokinetic or pharmacokinetic data from adults due to paucity of data that exists for children. This situation will be improved through the following specific aims:
- Collect image-based pharmacokinetic (PK) data from patient volunteers in different age groups scheduled for routine nuclear medicine studies for 4 radiopharmaceuticals commonly used in pediatric nuclear medicine
- Pool and analyze the data for different age groups for each radiopharmaceuticals and
- Generate biokinetic models to be used in subsequent dosimetric models for the optimization of pediatric nuclear medicine procedures.
Since inadequate pharmacokinetic data currently exist in these patients, the investigators will use the data acquired in this study to establish PK models applicable to different age categories. Data on the pharmacokinetics of agents used in pediatric nuclear medicine are almost completely lacking. Internationally adopted dose coefficients (mSv/MBq) for pediatric nuclear medicine make age-dependent adjustments only for patient size and anatomical differences, while time-dependent kinetics from adult PK models are assumed due to the lack of kinetic data for children. The data obtained from this study will make it possible for the first time to determine how the PK in pediatric patients differs from adults. This will be done for Tc-99m dimethylsuccinic acid (DMSA), a radiopharmaceutical commonly used for pediatric nuclear medicine imaging. The overall hope is that results will allow the molecular imaging community to implement pediatric dose-reduction approaches that substantially improve upon current guidelines pointing to future technological advances that could yield even greater dose-reduction while simultaneously improving diagnostic image quality.
详细描述
The overall objective of this investigation is to optimize pediatric patient absorbed dose by keeping it as low as possible while maintaining and even improving the diagnostic quality of nuclear medicine images. Current dosimetric estimations in children are based on either animal biokinetic or pharmacokinetic data from adults. This is due to paucity of data that exists specifically for children. This situation will be improved through the following specific aims:
- Collect imaging-based pharmacokinetic (PK) data from patient volunteers in different age groups scheduled for selected, routine nuclear medicine studies for 4 radiopharmaceuticals commonly used in pediatric nuclear medicine
- Pool and analyze the data for different age groups for each radiopharmaceuticals and
- Generate biokinetic models to be used in subsequent dosimetric models for the optimization of pediatric nuclear medicine procedures.
Pediatric absorbed dose estimates that are typically reported apply adult PK data with pediatric variations in body size and anatomy but not for differences in physiology between children and adults. Depending on the diagnostic agent, such differences can be of greater impact than anatomical differences. The investigators will acquire image data that will allow us to develop PK models for Tc-99m dimethylsuccinic acid (DMSA), a radiopharmaceutical commonly used in children for renal cortical imaging. Patients undergoing standard of care imaging will be asked to consent to being imaged at one additional time point, either prior or subsequent to the time typical for clinical imaging. No patient will be asked to undergo more than one additional imaging time-point.
It is important to note that the patient volunteers will not receive any additional radiation exposure for inclusion in this study. They are only being ask to allow imaging at an additional time point.
Patients ages 1-6 years old will be enrolled. Routine imaging will be performed 3-4 h post-administration (PA) with a dual-detector rotating gamma camera. In each age group, half of the subjects will also be imaged between 30 and 90 min, post-administration. The 2nd half will be imaged at 4-6 h, post-administration.
研究设计
- 研究类型
- Observational
- 观察模型
- Other
- 时间视角
- Other
入排标准
- 年龄范围
- 9 Months 至 6 Years（Child）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •All patients within the specified age ranges scheduled at Boston Children's Hospital for a nuclear medicine study utilizing Tc-99m DMSA will be eligible to volunteer for inclusion in this study. It is also essential that inclusion does not compromise the potential of acquiring the clinically indicated image acquisition.
排除标准
- •Inability to be imaged at the additional time point without the need for sedation or anesthesia
研究组 & 干预措施
Tc-99m DMSA
Patients aged 1-6 years old will be enrolled. Routine SPECT imaging will be performed 3-4 h post-administration (PA) with a dual-detector rotating gamma camera over a 360˚ rotation for 8 s per view using a 1282 matrix. In each age group, half of the subjects will also be imaged between 30 and 90 min, post-administration. The 2nd half will be imaged at 4-6 h, post-administration. It is important to note that the patient volunteers will not receive any additional radiation exposure for inclusion in this study. They are only being ask to allow imaging at one additional time point.
干预措施: Imaging Time (Drug)
结局指标
主要结局
Radioactivity in target organs at various time points
时间窗: 6 hours
The target-organ radioactivity measurements will be used to estimate the time-integrated activity in the target organs, hopefully leading to better estimates of absorbed dose to patients of different ages.
次要结局
未报告次要终点
研究者
Frederic Fahey
Professor of Radiology
Boston Children's Hospital