Hybrid SPECT/CT for Tracking of Mesenchymal Stem Cells after Intravenous and Intra-Thecal Administration in Acute Cervical Traumatic SpinalCord Injury

Introduction: Mesenchymal stem cells (MSCs) are a promising strategy for spinal cord repairafter traumatic spinal cord injury (tSCI), but their ability to migrate, engraft, and survive at injury sites has yet to be investigated in humans.Case Presentation: In this case report, using hybrid SPECT/CT, we found that radiolabeled autologous bone marrow-derived MSCs after intravenous administration distributed in the reticuloendothelial system and lung parenchyma, but accumulated unremarkably at the site of tSCI, whereas after intrathecal administration they spread rostraly in the cerebrospinal fluid and accumulated at the site of tSCI as early as 1 hour after administration, with increasing accumulation at 4 hours. The migration and homing potential of MSCs after intrathecal administration was maintained even one and a half years after tSCI. We observed no serious side effects during and after the procedure, however, neurologic recovery was minimal and could not be attributed solely to MSCs administration.Discussion: This case suggests that hybrid SPECT/CT imaging could be successfully used to track radiolabeled MSCs within the first day after intravenous and intrathecal administration of MSCs in a patient with tSCI without serious side effects.