Longitudinal amyloid burden with combined [11C]PiB and [18F]NAV4694 PET scans

Abstract The β-amyloid radiotracer [18F]NAV4694 is a desirable alternative to [11C]PiB, possessing similar imaging characteristics and favorable radiopharmaceutical distribution. This work examined the consistency of amyloid measures between [11C]PiB and [18F]NAV4694 as participants transition between radiotracers in longitudinal studies. Thirty-five participants with ≥1 [11C]PiB scans, followed by a [18F]NAV4694 scan, were recruited from ongoing AD studies at the University of Wisconsin. Amyloid stability was evaluated in Aβ- individuals and amyloid accumulation was evaluated in Aβ+ individuals. In Aβ- participants, [18F]NAV4694 measures were consistent with the preceding [11C]PiB measures, showing no significant differences in CL values. Aβ+ participants exhibited an average annualized Aβ accumulation of 6.0 ± 1.8 CL/yr, consistent with modeled [11C]PiB Aβ projected outcomes. [18F]NAV4694 demonstrated both consistency in trending amyloid accumulation and constancy in sustained Aβ- participants compared with [11C]PiB. This study highlights how both radiotracers can be integrated within a single analytical framework under a uniform processing pipeline.