Non-input analysis for incomplete trapping irreversible tracer with PET

作者：Ohya Tomoyuki^*; Kikuchi Tatsuya; Fukumura Toshimitsu; Zhang Ming Rong; Irie Toshiaki

来源：Nuclear Medicine and Biology, 2013, 40(5): 664-669.

DOI：10.1016/j.nucmedbio.2013.02.012

• Irreversible tracer
• Non-input analysis
• PET
• Quantitative analysis
• Tracer elimination

Introduction: When using metabolic trapping type tracers, the tracers are not always trapped in the target tissue; i.e., some are completely trapped in the target, but others can be eliminated from the target tissue at a measurable rate. The tracers that can be eliminated are termed 'incomplete trapping irreversible tracers'. These incomplete trapping irreversible tracers may be clinically useful when the tracer beta-value, the ratio of the tracer (metabolite) elimination rate to the tracer efflux rate, is under approximately 0.1. In this study, we propose a non-input analysis for incomplete trapping irreversible tracers based on the shape analysis (Shape), a non-input analysis used for irreversible tracers.
Methods: A Monte Carlo simulation study based on experimental monkey data with two actual PET tracers (a complete trapping irreversible tracer [C-11]MP4A and an incomplete trapping irreversible tracer [(18) F]FEP-4MA) was performed to examine the effects of the environmental error and the tracer elimination rate on the estimation of the k(3)-parameter (corresponds to metabolic rate) using Shape (original) and modified Shape (M-Shape) analysis. The simulation results were also compared with the experimental results obtained with the two PET tracers.
Results: When the tracer beta-value was over 0.03, the M-Shape method was superior to the Shape method for the estimation of the k(3)-parameter. The simulation results were also in reasonable agreement with the experimental ones.
Conclusions: M-Shape can be used as the non-input analysis of incomplete trapping irreversible tracers for PET study.

• 出版日期2013-7