Woods, Steven P2024-07-262024-07-262024-052024-05-13May 2024https://hdl.handle.net/10657/17643Pediatric brain tumors are among the most common cancers of childhood. As survival rates have improved, the emphasis among medical professionals has shifted from mere survival to maximizing quality of life. A conventional method of treatment, photon radiotherapy (XRT), subjects healthy brain tissue to toxic radiation exposure. This neurotoxicity often manifests as damage to microstructure of white matter tracts, which is measured through diffusion tensor imaging (DTI). Additionally, the neurotoxicity of XRT contributes to maladaptive neurocognitive function and quality of life. In recent decades, proton radiotherapy (PRT) has been theorized as a less neurotoxic alternative to XRT. The advantages of PRT have been empirically supported through DTI and neurocognitive outcomes research. However, PRT potentially confers some neurocognitive risk, especially in the domains of fine motor skills and processing speed and especially when PRT is administered via craniospinal irradiation (CSI). The current study examined fine motor skills, processing speed, and white matter structural integrity in pediatric brain tumor survivors who received PRT either via CSI (n = 33) or focally (n = 34). All participants completed a standardized neuropsychological battery and underwent MRI with DTI sequences. The focal and CSI PRT groups were compared on fine motor/processing speed outcomes and DTI metrics of white matter integrity using MANCOVAs. The relationship between DTI metrics and fine motor/processing speed outcomes was tested with multiple regression models. Analyses revealed that the CSI group had significantly worse fine motor speed/dexterity and psychomotor processing speed than the focal group. DTI analyses of white matter integrity showed mixed results, with weaker integrity of the forceps major and right corticospinal tract (CST) that did not remain significant after multiple comparisons corrections. Integrity of the CST and forceps major were significantly associated with fine motor speed/dexterity, although these associations did not remain significant after multiple comparisons correction. This study suggests that pediatric brain tumor survivors who received CSI PRT carry neurocognitive risk in fine motor skills/processing speed domains and white matter structural integrity, predictors and moderators of which remain to be determined.application/pdfenPediatric brain tumorsradiotherapywhite matterfine motorprocessing speedThesis2024-07-26