[P1–362]: DIAGNOSTIC UTILITY OF FDG‐PET TO CONFIRM A CLINICAL SUSPICION OF AMYOTROPHIC LATERAL SCLEROSIS

We performed a systematic review to assess the available evidence of FDG-PET utility in the diagnosis of Amyotrophic Lateral Sclerosis (ALS) with and without cognitive impairment. The search was performed on Medline, Embase and Cochrane on November 20, 2015. Critical outcomes for this PICO are sensitivity, specificity and accuracy of FDG-PET in distinguishing patients with ALS from patients with other pathologies or healthy people, as assessed versus clinical diagnosis. Minimum sample size was set at 10 subjects with the target condition. Data were extracted and assessed as to publication bias, heterogeneity, imprecision, risk of bias, indirectness, and applicability. We provide assessment of the quality of evidence, of the target effect, and of strength of recommendation. Out of the 16 papers selected, 2 reported the outcomes of interest. These provided moderate quality of evidence (Table) that hypometabolic regions including the prefrontal cortex, thalamus, primary motor cortex, striatum and posterior cingulate can distinguish ALS patients from healthy controls with 94.8–95.4% sensitivity, 80.0–82.5% specificity and 91.8–93.2% accuracy (Laere et al., 2014; and Pagani et al., 2014). Concerns regarding the applicability of FDG-PET as assessed here are due to the use of semiquantitative methods of image analysis (increasingly but not yet routinely adopted in clinical context). The available data provide moderate quality of evidence for high diagnostic utility of FDG-PET in distinguishing ALS patients from healthy controls. However, all studies were performed considering baseline clinical diagnosis as the reference standard, raising doubt on either methodological validity or the actual clinical usefulness of FDG-PET in improving clinical diagnosis. We conclude for a doubtful recommendation for clinical use of FDG-PET in the diagnosis of ALS. Further research is warranted to provide proper assessment of the incremental value of FDG-PET on this issue.