Clinical utility of FDG-PET in amyotrophic lateral sclerosis and Huntington’s disease

Abstract

Relative to other neurodegenerative diseases, the clinical use of FDG-PET in ALS and HD is still in its infancy. Once validated by disease-control studies, FDG-PET might represent a potentially useful biomarker for ALS diagnosis. FDG-PET is presently not justified as a routine investigation to predict conversion to HD, nor to detect evidence of brain dysfunction justifying cognitive decline in ALS and HD.

European Association of Nuclear Medicine and European Academy of Neurology recommendations for the use of brain 18F‐fluorodeoxyglucose positron emission tomography in neurodegenerative cognitive impairment and dementia: Delphi consensus

“…Literature searches, assessments and decisions answered whether FDG‐PET should be performed as adding diagnostic value (in terms of increased accuracy and versus clinical confirmation) compared to standard clinical/neuropsychological assessment alone to confirm a clinical suspicion of ALS in patients with or without cognitive impairment (section PICO 17); to detect brain dysfunction related to cognitive deterioration in patients with ALS (section PICO 18); to pick early signs of neurodegeneration in patients with a genetic risk of HD (section PICO 19); and to discriminate frontal‐lobe hypometabolism responsible for cognitive deterioration in patients with HD (section PICO 20). The panel did not support the clinical use of FDG‐PET for any of these aims .…”

“…The evidence assessment for the 21 literature searches, available at https://drive.google.com/open?id=0B0_ JB3wzTvbpVFYtUGxHdGZWYmc (Data S2), is reported in detail in dedicated review papers [23][24][25][26][27][28][29] and briefly summarized in the pertinent sections below. All panellists filled the whole questionnaire at each of the four rounds.…”

Clinical utility of FDG PET in Parkinson’s disease and atypical parkinsonism associated with dementia

“…Delphi decisions for the other PICO questions of the EANM/EAN initiative led to supporting FDG PET in all clinical scenarios [1] with the exception of preclinical cases [9] and of amyotrophic lateral sclerosis and Huntington’s disease [10]…”

Assessing FDG-PET diagnostic accuracy studies to develop recommendations for clinical use in dementia

“…In order to facilitate the communication on available evidence with panelists, we produced, besides the tables with all extracted data for each PICO, summary of findings tables reporting the outcomes assessed globally across papers, and abstracts better elucidating all findings (see (23)(24)(25)(26)(27)(28)(29). These explained both the quantitative data as based on the methodological assessment described, and the "qualitative" findings, as based on the pattern of hypometabolism correlated to the target disorders for each PICO.…”

“…Considering overall the quality of methodology (type of gold-or reference-standard and head-tohead comparison between index-test and comparator), the number of total subjects for PICO, effect sizes, and consistency of results across studies (see (23)(24)(25)(26)(27)(28)(29)), PICO 21 resulted the only one with relatively good evidence. PICO 21 had a total of 9 studies with validated measures of accuracy as proper critical outcomes, with a total of 586 subjects, and considerably high and consistent values of effect size (Tables 5 and 6; (28)); for this PICO, only 3 studies had inadequate reference standard (only baseline clinical diagnosis) (28).…”