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Progressive multifocal leukoencephalopathy (PML) mimicking high-grade glioma on delayed F-18 FDG PET imaging
Koen Mertens1, Marjan Acou, Caroline Van den Broecke
1Department of Nuclear Medicine, Polikliniek 7, Ghent University Hospital, De Pintelaan 185, Gent 9000, Belgium.
Abstract:
The purpose of our study was to determine the increase in F-18 fluorodeoxyglucose (FDG) uptake in a patient with progressive multifocal leukoencephalopathy (PML) between early and late scan times using positron emission tomography (PET) imaging with F-18 FDG at conventional (60 minutes [min] after injection, PET(60)) and delayed (300 min after injection, PET(300)) intervals. PET(60) and PET(300) imaging was performed on a pathologically proven PML lesion. The PML lesion in the posterior fossa exhibited an increase in F-18 FDG uptake of 52% between early and late times, which was in the range of that in high-grade gliomas. Thus, dual-time-point PET with F-18 FDG may not be able to differentiate between infectious and malignant brain lesions.
Insights
Dual-time-point F-18 FDG PET imaging showed increased uptake in a progressive multifocal leukoencephalopathy (PML) lesion. This finding, similar to high-grade gliomas, suggests limitations in differentiating infectious from malignant brain lesions.
Area of Science:
- Neurology
- Nuclear Medicine
- Radiology
Background:
- Progressive multifocal leukoencephalopathy (PML) is a rare, demyelinating disease of the central nervous system.
- Differentiating PML from malignant brain tumors can be challenging, impacting treatment decisions.
- Positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) is used to assess metabolic activity in brain lesions.
Observation:
- This study investigated the change in F-18 FDG uptake in a pathologically confirmed PML lesion between early (PET(60)) and delayed (PET(300)) imaging intervals.
- PET imaging was performed at 60 minutes and 300 minutes post-injection of F-18 FDG.
Findings:
- The PML lesion demonstrated a significant increase in F-18 FDG uptake of 52% between the early and delayed scan times.
- This increased uptake pattern falls within the range observed in high-grade gliomas.
Implications:
- Dual-time-point F-18 FDG PET imaging may not reliably distinguish between infectious etiologies like PML and malignant brain lesions.
- Further research is needed to identify imaging biomarkers that can differentiate these conditions.
- This finding has potential implications for diagnostic accuracy and patient management in neuro-oncology and neuroinfectious diseases.
