Structural and Functional Changes in the Central Nervous System Following Cancer Therapy

Abstract

Chemotherapy Induced Peripheral Neuropathy (CIPN) is known to impact negatively on patients' quality of life. It has been reported that these patients tend to have sensitivity thresholds to stimuli, such as pain and temperature, that are different from those of normal subjects. The effect of chemotherapeutic agents on the central nervous system (CNS) has been observed; however, most of the mechanisms involved are not exactly understood. A quantitative investigation into the temperature sensitivity changes in the spinal cords and brains of chemotherapy patients would provide important information in understanding the side effects of this treatment modality. In the first part of the project, the temperature perceptional changes in terms of brain activation patterns of the chemotherapy patients with CIPN are studied using brain function MRI. In the second part of the project, the structural changes of the brain and spinal cord of chemotherapy patients with CIPN are studied using diffusion tensor imaging (DTI). High b-value (b = 1500 s/mm2) and low b-value (b=650 s/mm2) settings will be use during the spinal cord DTI scans. Due to the sample size limitation, no comparison between healthy volunteers and CIPN patients can be done based on the existing temperature fMRI data. However, the developed temperature fMRI protocol shows good reliability in detecting temperature response. Based on the spinal cord DTI result using b = 1500 s/mm2, decrease in FA value has been observed. The corresponding FA values of CIPN patient and healthy volunteers are 0.28±0.10 and 0.41±0.02 , respectively. (t-test = 2.63 >2.447, p=0.05 level of significant) However, no significant difference is observed in other diffusion parameters. This results also suggests that application of high b-value setting is more suitable as it is better at detecting diffusion at microstructure.