Molecular Imaging (PET and SPECT) for Children with Hypoxic-Ischemic-Encephalopathy and Cerebral Palsy Before and After Cell Therapy
Introduction: Glucose metabolism has been the focus of research in order to understand pathological conditions associated with diseases such as neonatal Hypoxic- Ischemic-Encephalopathy (HIE), Cerebral Palsy (CP) and cerebral infarction.
Objective: To evaluate the use of molecular imaging (SPECT and PET) for children with HIE and CP before and after cell therapy, and to propose future perspectives on the use of those modalities for assessment of brain function in children with these conditions.
Methods: PubMed search for studies using PET or SPECT scans for HIE and CP in children.
Results: We identified 18 PET and 17 SPECT studies that have been performed in cases under age of 19 over the past three decades (1991-2021). Six papers on PET use consisted of one with human Umbilical Cord derived Mesenchymal Stromal Cells, one mobilized Peripheral Blood Mononuclear Cells, three autologous Bone Marrow Mononuclear Cells and one allogeneic Umbilical Cord Blood. 4/6 papers reported that PET-CT scan revealed increased glucose metabolism and 1/6 showed no significant change in glucose metabolism after cell therapy. One article on SPECT reported that 2/5 cases had improvement of cerebral perfusion in the thalamus after treatment.
Discussion: SPECT in the first few weeks of life is useful and more sensitive than MRI in predicting major neurological disability. SPECT is not appropriate for neonates because of the risk of radiation, improvement of other clinical test equipment. PET studies reported high glucose metabolisms in the early neonatal period of children with mild to moderate HIE, but not in the most severe cases, including those neonates that died. We suggested that PET could be more useful tool to estimate effectiveness of stem cell therapy than SPECT.
Conclusion: PET might be good clinical modalities to clarify mechanism of stem cell therapy for CP. We need further clinical studies to clarify more precisely.