11C-PiBを用いたアミロイドPET

Amyloid PET using C-11 PiB

PiBは，Pittsburgh compound Bの略で，アミロイドPETの事実上の標準（de facto standard）の地位を確立した薬剤である。本項では，PiB PETによって集積されてきたアルツハイマー病（Alzheimer’s disease：AD）に関する膨大な知見の中から，アミロイドPETの臨床や今後の研究を進めるうえで，参考となるようなPiB PETの知見について述べる。

PiB is a C-11 labelled amyloid PET tracer, which has greatly contributed to understanding the clinical and pathophysiological significance of amyloid accumulation in Alzheimer’s disease. Post-mortem studies have demonstrated that the accumulation of PiB reflects the density of amyloid plaque. Equivocal scan of PiB, which is a visual read criteria suggested in J-ADNI study, may show a risk of progression of AD. Longitudinal data confirmed that amyloid deposition increases with a sigmoid curve in the progression of AD. SUVR of PET with F-18 amyloid tracer can be transformed to Centiloid scale through SUVR of PiB PET. PiB will continue to be used in the future.