The potential of positron emission tomography (PET) scans with the radiotracer (18F)-Flortaucipir (FTP) to detect abnormal protein folds in the brain, a symptom of chronic traumatic encephalopathy (CTE), may not be applicable for diagnosing this condition in former professional American-style football players, according to a recent study published in the Journal of Neurotrauma.
Dr. Aaron Baggish and his team at Massachusetts General Hospital conducted research that compared former professional players with individuals who had not been exposed to repetitive head impacts. The research found no substantial differences in (18F)-FTP uptake between the two groups, and within the former players, no links were found between neurocognitive functioning and (18F)-FTP uptake.
In their conclusion, the authors expressed doubt over the effectiveness of (18F)-FTP PET for evaluating CTE in former professional football players. They questioned its utility, as the uptake of the tracer did not increase in brain regions previously associated with CTE.
Journal of Neurotrauma’s Editor-in-Chief, Dr. David L. Brody, praised the meticulous study design and remarked on the significance of the negative results. He was not surprised given the distinctive abnormal tau folds seen in CTE compared to Alzheimer’s disease and other tauopathies.
American-style football players are exposed to repetitive head impacts, which may lead to CTE. Currently, a conclusive CTE diagnosis requires the identification of localized hyperphosphorylated Tau (p-Tau) after death. Although some studies have suggested that PET with the radiotracer [18F]-Flortaucipir (FTP) might detect p-Tau in living individuals, this recent study raises questions about its effectiveness.
The research further explored associations between FTP, football exposure, and objective neuropsychological measures among former professional football players. Participants underwent structural magnetic resonance imaging and PET using FTP for p-Tau. The football exposure was quantified based on a variety of factors, including the age at first exposure and duration of professional career.
Despite the rigorous testing, no significant differences were found in (18F)-FTP uptake among the football players compared with the control group. Furthermore, there were no associations between objective measures of neurocognitive functioning and (18F)-FTP uptake.
The researchers highlighted a marginally significant difference in (18F)-FTP uptake isolated to the entorhinal cortex among players, suggesting that this could be an area of future investigation. Despite this, the general absence of increased [18F]-FTP uptake among former players questions the utility of this method for clinical evaluation of CTE.