Standardized Expression of 18F-NAV4694 and 11C-PiB β-Amyloid PET Results with the Centiloid Scale

• Published in: The Journal of nuclear medicine (1978) Vol. 57; no. 8; pp. 1233 - 1237
• Main Authors: Rowe, Christopher C, Jones, Gareth, Doré, Vincent, Pejoska, Svetlana, Margison, Laura, Mulligan, Rachel S, Chan, J Gordon, Young, Kenneth, Villemagne, Victor L
• Format: Journal Article
• Language: English
• Published: United States 01.08.2016
• Subjects: Adult; Amyloid beta-Peptides - metabolism; Benzofurans - pharmacokinetics; Benzothiazoles - pharmacokinetics; Brain - diagnostic imaging; Brain - metabolism; Female; Fluorine Radioisotopes - pharmacokinetics; Humans; Hydrocarbons, Fluorinated - pharmacokinetics; Image Interpretation, Computer-Assisted - standards; Male; Molecular Imaging - standards; Positron-Emission Tomography - methods; Positron-Emission Tomography - standards; Practice Guidelines as Topic; Protein Interaction Mapping - standards; Radiopharmaceuticals - pharmacokinetics; Reproducibility of Results; Sensitivity and Specificity; Tissue Distribution; beta-amyloid; centiloid; standardization; amyloid imaging; Alzheimer’s disease
• ISSN: 1535-5667
• DOI: 10.2967/jnumed.115.171595

A common quantitative output value for PET measures of β-amyloid (Aβ) binding across tracers and methods would allow better comparison of data across sites and application of universal diagnostic and prognostic values. A method has recently been developed that generates a unit of measurement called the centiloid. We applied this method to 2-[2-(18)F-fluoro-6-(methylamino)-3-pyridinyl]-1-benzofuran-5-ol ((18)F-NAV4694) and (11)C-Pittsburgh compound B ((11)C-PiB) Aβ images to derive the scaling factor required to express tracer binding in centiloids. Fifty-five participants, including 10 young controls (33 ± 7 y old), underwent both (11)C-PiB and (18)F-NAV4694 imaging no more than 3 mo apart, with the images acquired 50-70 min after tracer injection. The images were spatially normalized and analyzed using the standard centiloid method and regions (cortex and whole-cerebellum reference) downloaded from the Global Alzheimer Association Interactive Network website. SUV ratios (SUVRs) showed a strong correlation in tracer binding ((18)F-NAV4694 SUVR = 1.09 × (11)C-PiB SUVR - 0.08, R(2) = 0.99). The equation to convert (18)F-NAV4694 to centiloids [100 × ((18)F-NAV4694 SUVR - 1.028)/1.174] was similar to a published equation for (11)C-PiB [100 × ((11)C-PiB SUVR - 1.009)/1.067]. In the young controls, the variance ratio ((18)F-NAV4694 centiloid SD divided by (11)C-PiB centiloid SD) was 0.85. The results for both (11)C-PiB and (18)F-NAV4694 can now be expressed in centiloids, an important step that should allow better clinical and research use of Aβ imaging. The standard centiloid method also showed that (18)F-NAV4694 has slightly higher Aβ binding and lower variance than (11)C-PiB, important properties for detecting early Aβ deposition and change over time.