PET radiotracer Chemical name and structure Application in ALS References [11 C]PBR28 [11 C]PBR28 (aryloxianilide)11 C]methoxybenzyl)-2-phenoxy-5-pyridinamine Increased uptake in motor regions and the precentral gyrus in ALS patients as compared with controls and the lung, spine, and brain (primarily the hindbrain) in mouse models. [49 –52 ] [11 C]PK11195 N-(sec-butyl)-1-(2-chlorophenyl)-N-(methyl-11 C)isoquinoline-3-carboxamide Several regions with increased uptake, including the motor cortex, frontal lobe, thalamus, occipital lobe, temporal lobe, pons, sensorimotor cortex, and cerebellum when compared to controls. [55 , 56 ] [18 F]DPA714 N,N-diethyl-2-(2-(4-(2-(fluoro-18 F)ethoxy)phenyl)-5,7-dimethylpyrazolo[1,5-a]pyrimidin-3-yl)acetamide Increased primary motor cortex uptake in humans and increased brainstem uptake in mice models. [52 , 57 ] [11 C](l)-deprenyl-D2 or [11 C]DED (R)-N-(methyl-11 C)-N-(1-phenylpropan-2-yl)prop-2-yn-1-amine-1,1-d2 Increased uptake in pons and white matter, decreased uptake in parietal and temporal areas when compared to controls. [59 ] [18 F]THK5351 (R)-1-(fluoro-18 F)-3-((2-(6-(methylamino)pyridin-3-yl)quinolin-6-yl)oxy)propan-2-ol Multiple regions with increased uptake, such as the precentral gyri, motor cortex, and temporal lobes. Sample size is limited. [60 , 62 ] [11 C]KD2 N-((1s,3s)-adamantan-1-yl)-8-(methoxy-11 C)-4-oxo-1-pentyl-1,4-dihydroquinoline-3-carboxamide Demonstrated specific uptake in ALS postmortem spinal cord tissue. [64 ] [18 F]RS-126 N-((1s,3s)-adamantan-1-yl)-1-(2-(2-(fluoro-18 F)ethoxy)ethyl)-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxamide No specific binding to CB2 receptors in ALS postmortem spinal tissue. [63 ] [11 C]RS-028 1-(2-Ethoxyethyl)-N-((1r,3r)-3-hydroxyadamantan-1-yl)-8-(methoxy-11 C)-4-oxo-1,4-dihydroquinoline-3-carboxamide Increased and specific binding to ALS postmortem spinal tissue compared to control tissue. [63 ]
