Abstract / Summary
It is not yet clear whether there are differences in the impact of different chemotherapy regimens on brain function. Especially, the distinct brain network alterations between patients underwent different regimens are still unclear. This study aimed to explore regimen-associated differences in resting-state brain networks between colorectal cancer (CRC) patients receiving 5-FU-based chemotherapy and NSCLC patients receiving carboplatin-based chemotherapy, without inferring direct causation due to inherent clinical heterogeneity. A total of 43 CRC patients after receiving 2–3 month-long fluorouracil-based chemotherapy and 54 NSCLC patients underwent 2–3 month-long carboplatin-based chemotherapy were enrolled. At end of treatment, MRI data were acquired and preprocessed from patients. Firstly, brain networks were constructed based on resting-state functional MRI data. Then nodal metrics were computed and compared between CRC and NSCLC groups. Secondly, resting-state networks were identified using group independent component analysis method. Both static functional network connectivity (sFNC) and dynamic FNC (dFNC) were calculated to evaluate resting-state network connectivity. Firstly, compared with CRC patients received 5-fluorouracil-based chemotherapy, NSCLC patients undergone carboplatin-based chemotherapy showed decreased nodal degree and decreased nodal global efficiency of the left precuneus, which survived the multiple comparison correction. Secondly, compared to NSCLC patients, CRC patients showed decreased intra-FNC in the right cuneus of the precuneus network. In additionally, CRC patients exhibited decreased inter-FNC between dorsal default mode network (dDMN) and salience network (SN), dDMN and language network (LN), ventral DMN and primary visual network (PVN), sensorimotor network (SMN) and PVN. Moreover, four dynamic states identified, and CRC patients demonstrated decreased mean dwell time and fractional windows in State 2, as well as increased dFNC between SN and right executive control network (RECN), SMN and LN, PVN, decreased dFNC between left ECN (LECN) and SMN, auditory network, PVN, right ECN and SMN in State 2. Notably, the graph theory findings were corrected for multiple comparisons and are more robust, whereas the sFNC/dFNC findings are exploratory and require validation. In this study, carboplatin-based regimens were associated with more pronounced alterations in left precuneus topology. Distinct chemotherapy-related abnormalities of sFNC and dFNC were found in the brain of CRC and NSCLC patients after receiving different chemotherapy regimens. However, given the heterogeneity (different cancer types, metastatic patterns, and multiple regimens within each group), these findings should be interpreted as regimen-associated associations rather than direct evidence of differential neurotoxicity.