Quantitative F-18 Flute PET provides more data about brain amyloid

F-18 Flutemetamol (F-18 Flute) alone has been used to procure positive or negative results in visual interpretations of beta-amyloid in the brain as a tool to aid in the diagnosis and study of Alzheimer’s disease. Quantitative analysis could further supercharge this technique by bringing in more data about regional and total tracer uptake, according to a study published Aug. 21 in the Journal of Nuclear Medicine.

Researchers including Lennart Thurfjell, PhD, from the Institute of Neuroscience and Physiology, University of Gothenburg in Gothenburg, Sweden, evaluated quantitative PET in a large retrospective study to see how effective it was.

“[Q]uantification provides additional information about regional and global tracer uptake and may have utility for image assessment over time and across different centers,” wrote Thurfjell et al. “Using postmortem brain neuritic plaque density data as a truth standard to derive a standardized uptake value ratio (SUVR) threshold, we assessed a fully automated quantification method comparing visual and quantitative scan categorizations.”

For this study, information from 345 people was gathered from eight previous clinical studies involving F-18 Flute PET. Data was grouped into three separate cohorts including an autopsy group of 68 patients, another group of 172 study patients with either mild cognitive impairment, probably Alzheimer’s disease and healthy volunteers, and a third group of 105 healthy volunteers for defining SUVR reference.

“Quantification of F-18 flutemetamol amyloid imaging data using an automated PET-only method and categorization of scans using an SUVR threshold derived from an autopsy cohort gave excellent concordance with majority visual read results,” the researchers wrote.

The researchers pointed out that using the pons as the reference region lended a tighter relationship with visual interpretation then using cerebellar gray matter and the whole cerebellum. However all three regions were deemed useful as a reference.

Thurfjell is also a researcher for GE Healthcare, a noted affiliation for this study. F-18 Flute is still investigational and more study and regulatory approval is needed before it could be used in the clinical evaluation of Alzheimer’s and other dementias.