Dopamine Transporter Imaging Using 99mTc-TRODAT-1 SPECT in Parkinson’s Disease

Abstract

BackgroundAlthough the decrease in striatal dopamine transporter (DAT) density has been described in North American, European, and Asian Parkinson’s disease (PD) patients, studies on this issue are required in the rest of the world. This study examined the diagnostic utility of DAT imaging in Brazilian PD patients.Material/MethodsTwenty PD patients (13 males, 7 females, median age: 62 years, median age at disease onset: 56 years, median disease duration: 5 years, and median UPDRS-III score: 29) and 9 age- and sex-matched healthy subjects underwent single-photon emission computerized tomography (SPECT) using 99mTc-TRODAT-1.ResultsPD patients showed a significant decrease in the striatum, caudate nucleus, and putamen DAT densities compared with data from healthy subjects. Striatal 99mTc-TRODAT-1 bindings had the highest diagnostic accuracy compared to those estimates from caudate nucleus and putamen. For the diagnosis of PD, a striatal 99mTc-TRODAT-1 binding cut-off value of 0.90 was associated with a sensitivity of 100% and a specificity of 89%. There was no significant difference between striatal 99mTc-TRODAT-1 binding values provided by different readers, contrary to 99mTc-TRODAT-1 binding estimates in the caudate nucleus.ConclusionsStriatal DAT imaging using 99mTc-TRODAT-1 can be considered a marker for differentiating PD patients from healthy individuals, with a good interobserver reproducibility.

The Treadmill Exercise Protects against Dopaminergic Neuron Loss and Brain Oxidative Stress in Parkinsonian Rats

“…Although it is usually accepted that parkinsonian symptoms develop when approximately 70–80% of DA neurons are lost, imaging studies have shown that a loss around 50% of DA terminals is required for the onset of symptoms in PD patients [ 54 ]. There is an exponential decline of DAT, as the disease progresses, that can be revealed by imaging technics [ 55 ], making DAT a marker for distinguishing PD patients from healthy individuals [ 56 ].…”

A Real-World Study of Cerebral 99mTc-TRODAT-1 Single-Photon Emission Computed Tomography (SPECT) Imaging of the Dopamine Transporter in Patients with Parkinson Disease from a Tertiary Hospital in Brazil

“…Normal versus abnormal scans took into consideration a previous study of our group that assigned cutoff values in DAT imaging scans of Brazilian PD patients versus healthy control individuals [ 14 ]. Figure 2 shows illustrative normal and abnormal scans.…”

“…Indeed, DAT imaging is easier to interpret than modern magnetic resonance imaging, and it has a lower cost than positron emission techniques [ 13 ]. Two Brazilian studies using DAT imaging to differentiate PD patients from normal healthy subjects showed that this technique had high sensitivity (100%) and specificity (89%) [ 14 , 15 ].…”

The role of neuroimaging in Parkinson’s disease

“…The main advantage of [ 99m Tc]Tc-TRODAT-1 is its low price compared to tracers labeled with cyclotron-produced isotopes (e.g., 123 I or 18 F), because 99m Tc can be obtained from 99 Mo/ 99m Tc generators. This might be the reason why studies with [ 99m Tc]Tc-TRODAT-1 are mostly performed in Asia and South America (Ferraz, 2014;Hossein-Tehrani et al, 2020;Hwang et al, 2004;Sasannezhad et al, 2017;Sood et al, 2021). (Appel et al, 2015), 40-50 min for [ 18 F]PR04.MZ (Juri et al, 2021;Kramer, Juri, et al, 2020), >80 min for [ 11 C]RTI-32 (Guttman et al, 1997), and 3-4 h for [ 18 F]CFT (Laakso et al, 1998).…”