Abnormal topological organization in white matter structural networks in survivors of acute lymphoblastic leukaemia with chemotherapy treatment

// Liwei Zou 1, * , Lianzi Su 1, * , Rongmiao Qi 1, * , Fang Bao 1 , Xianjing Fang 1 , Longsheng Wang 1 , Zhimin Zhai 2 , Dan Li 3 and Suisheng Zheng 1, 4 1 Department of Radiology, The Second Hospital of Anhui Medical University, Anhui, China 2 Department of Hematology, The Second Hospital of Anhui Medical University, Anhui, China 3 Department of Scientific Research, The Second Hospital of Anhui Medical University, Anhui, China 4 Medical Image Research Center, Anhui Medical University, Anhui, China * Co-first authors Correspondence to: Suisheng Zheng, email: zhengss0509@sina.com Keywords: acute lymphoblastic leukaemia, chemotherapy, network, white matter, diffusion tensor imaging Received: March 22, 2017      Accepted: June 16, 2017      Published: July 08, 2017 ABSTRACT Previous diffusion tensor imaging (DTI) studies have detected white matter (WM) integrity abnormalities in some specific fibre bundles in acute lymphoblastic leukaemia (ALL) patients with chemotherapy. However, little is known about the changes in the topological organization of the WM structural network in ALL patients with chemotherapy. In the present study, we acquired DTI datasets from 28 ALL patients (mean age: 40.71 ± 8.58 years, years since diagnosis: 7–38) with chemotherapy and 20 matched healthy controls (mean age: 42.95 ± 6.39 years) and performed WM network analysis using a deterministic fibre-tracking approach. Graph theoretical analysis was used to compare the topological parameters of the WM networks between the two groups. Both ALL patients with chemotherapy and healthy controls had small-worldness in their WM networks. ALL patients showed significantly reduced global network efficiency, as indicated by the abnormally decreased clustering coefficient Cp and the normalized clustering coefficient γ and increased shortest path length Lp compared with healthy controls. Moreover, hubs were located more in parietal regions of healthy controls and in temporal regions in the ALL patients. We revealed the abnormal topological organization of the WM networks of ALL patients with chemotherapy, which may improve our understanding of the neural mechanism of chemotherapy in ALL from a WM topological organization level.