Chemotherapy Potentially Facilitates the Occurrence of Radiation Encephalopathy in Patients With Nasopharyngeal Carcinoma Following Radiotherapy: A Multiparametric Magnetic Resonance Imaging Study

Immunotherapy may promote the occurrence of radiation-induced brain injury in NSCLC patients with brain metastases undergoing radiotherapy: a retrospective propensity score-matching and inverse probability of treatment weighting study

PURPOSE

The combination of radiotherapy (RT) and immunotherapy can significantly improve the prognosis of non-small cell lung cancer (NSCLC) patients. However, concerns about whether the synergistic effect may increase the risk of radiation-induced brain injury (RIBI) remain controversial. This study aims to explore the impact of immune checkpoint inhibitors (ICIs) on the occurrence of RIBI in patients with NSCLC brain metastases (BMs).

METHODS

This study retrospectively enrolled NSCLC patients with BMs undergoing RT between January 2017 and December 2023. Patients were stratified into groups based on PD-1/PD-L1 checkpoint inhibitors, administration, with confounding factors controlled via propensity score matching (PSM) and inverse probability of treatment weighting (IPTW). Final cohorts included an RT-only group (n = 54) and an RT + ICIs group (n = 28). RIBI incidence and progression-free survival (PFS) were compared between groups.

RESULTS

After 1:1 PSM analysis, the incidence of RIBI in the RT + ICIs group was significantly higher than that in the RT-only group (17.9% vs 42.9%, P = 0.042). Further IPTW analysis showed that the incidence of RIBI in the RT + ICIs group was significantly higher than that in the RT-only group (24.8% vs 47.8%, P = 0.033). Regarding the impact on PFS, there was no statistical difference between the two groups in both PSM and IPTW (P > 0.05).

CONCLUSIONS

Immunotherapy combined with RT may increase the occurrence of RIBI in patients with NSCLC BMs. The mechanism underlying this phenomenon requires further investigation.

Alterations in surface-based amplitude of low-frequency fluctuations primary open-angle glaucoma link to neurotransmitter profiling and visual impairment severity

The study aimed to examine alterations in surface-based amplitude of low-frequency fluctuations (ALFF) and fractional amplitude of low-frequency fluctuations (fALFF) in primary open-angle glaucoma (POAG) patients using resting-state functional magnetic resonance imaging (rs-fMRI), and to investigate their relationships with visual function and molecular profiling. A total of 70 POAG patients and 45 age- and sex-matched healthy controls (HCs) underwent rs-fMRI scans. The differences between POAG and HCs groups were compared by two-sample t-test. Spearman's correlation analyses assessed the relationship between ALFF/fALFF values and ophthalmic parameters. Spatial correlation analysis of the patients-control difference map with brain imaging data further explores underlying neurobiological mechanisms. POAG patients displayed altered brain activity compared to HCs, including decreased ALFF/fALFF in the visual network and increased in the frontoparietal and default mode networks. They exhibited reduced fALFF in the somatomotor network and increased ALFF in the dorsal and ventral attention networks. These changes are linked to neurotransmitter systems, with fALFF particularly associated with the dopamine system. Moreover, the altered ALFF/fALFF in brain regions related to vision and attention - the occipital lobe, temporal lobe, parietal lobe, paracentral lobule, and frontal lobe correlated with ophthalmic examination parameters. Surface-based ALFF/fALFF in POAG decreased in visual processing regions and increased in brain regions related to cognitive control, working memory, and attention. These changes were linked to neurotransmitter distributions important for emotional stability and mental health, potentially informing treatment approaches for POAG patients.

Altered neural intrinsic oscillations in patients with multiple sclerosis: effects of cortical thickness

Objective

To investigate the effects of cortical thickness on the identification accuracy of fractional amplitude of low-frequency fluctuation (fALFF) in patients with multiple sclerosis (MS).

Methods

Resting-state functional magnetic resonance imaging data were collected from 31 remitting MS, 20 acute MS, and 42 healthy controls (HCs). After preprocessing, we first calculated two-dimensional fALFF (2d-fALFF) maps using the DPABISurf toolkit, and 2d-fALFF per unit thickness was obtained by dividing 2d-fALFF by cortical thickness. Then, between-group comparison, clinical correlation, and classification analyses were performed in 2d-fALFF and 2d-fALFF per unit thickness maps. Finally, we also examined whether the effect of cortical thickness on 2d-fALFF maps was affected by the subfrequency band.

Results

In contrast with 2d-fALFF, more changed regions in 2d-fALFF per unit thickness maps were detected in MS patients, such as increased region of the right inferior frontal cortex and faded regions of the right paracentral lobule, middle cingulate cortex, and right medial temporal cortex. There was a significant positive correlation between the disease duration and the 2d-fALFF values in the left early visual cortex in remitting MS patients (r = 0.517, Bonferroni-corrected, p = 0.008 × 4 < 0.05). In contrast with 2d-fALFF, we detected a positive correlation between the 2d-fALFF per unit thickness of the right ventral stream visual cortex and the modified Fatigue Impact Scale (MFIS) scores (r = 0.555, Bonferroni-corrected, p = 0.017 × 4 > 0.05). For detecting MS patients, 2d-fALFF and 2d- fALFF per unit thickness both performed remarkably well in support vector machine (SVM) analysis, especially in the remitting phase (AUC = 86, 83%). Compared with 2d-fALFF, the SVM model of 2d-fALFF per unit thickness had significantly higher classification performance in distinguishing between remitting and acute MS. More changed regions and more clinically relevant 2d-fALFF per unit thickness maps in the subfrequency band were also detected in MS patients.

Conclusion

By dividing the functional value by the cortical thickness, the identification accuracy of fALFF in MS patients was detected to be potentially influenced by cortical thickness. Additionally, 2d-fALFF per unit thickness is a potential diagnostic marker that can be utilized to distinguish between acute and remitting MS patients. Notably, we observed similar variations in the subfrequency band.

Application value of 3D pCASL in early assessment of potential radiation encephalopathy in nasopharyngeal carcinoma patients undergoing radiotherapy

OBJECTIVE

The study explores the application value of three-dimensional arterial spin labeling magnetic resonance imaging (3D pCASL) in early assessment of radiation encephalopathy (REP) in patients with nasopharyngeal carcinoma (NPC).

METHODS

A retrospective analysis of 39 cases of NPC was performed. Routine enhanced MRI scan and 3D pCASL imaging were used to examine the apparent diffusion coefficient (ADC) and brain blood flow (CBF) before and after treatment with intensity-modulated radiotherapy (IMRT). Dosimetric analysis of irradiation was performed. Receiver operating characteristic curve (ROC) was used to analyze diagnostic performance of two imaging methods.

RESULTS

There was no statistically significant difference between the two methods for the measurement of temporal white matter ADC, but statistically significant difference was found in CBF. 3D pCASL imaging showed more sensitivity, specificity and higher accuracy than conventional MRI enhanced scan in showing REP. The maximum dose of the temporal lobe was at the enhanced area.

CONCLUSION

The present study demonstrates that 3D pCASL scan at month 3 can reflect blood flow perfusion differences in NPC patients after IMRT and can accurately assess the possibility of REP at early stage. Enhanced areas have a higher probability of REP than the surrounding areas.

ADVANCES IN KNOWLEDGE

There is few magnetic resonance angiography studies used to evaluate arterial circulation on its application on potential REP after radiotherapy for NPC. In our study, we evaluate the application value of 3D pCASL in the early assessment of potential REP in patients with NPC after radiotherapy. The study was to provide an improved understanding of the early specific characteristics on MRI imaging and evolution of potential radiation encephalopathy using 3D pCASL technique, which can quantitatively evaluate the changes of blood flow in tissues at early stage and help to diagnose and treat potential radiation encephalopathy as early as possible.

MRI-based radiomics models for the early prediction of radiation-induced temporal lobe injury in nasopharyngeal carcinoma

Objective

This study was conducted to develop and validate a radiomics-clinics combined model-based magnetic resonance imaging (MRI) radiomics and clinical features for the early prediction of radiation-induced temporal lobe injury (RTLI) in patients with nasopharyngeal carcinoma (NPC).

Methods

This retrospective study was conducted using data from 130 patients with NPC (80 patients with and 50 patients without RTLI) who received radiotherapy. Cases were assigned randomly to training (n = 91) and testing (n = 39) datasets. Data on 168 medial temporal lobe texture features were extracted from T1WI, T2WI, and T1WI-CE MRI sequences obtained at the end of radiotherapy courses. Clinics, radiomics, and radiomics–clinics combined models (based on selected radiomics signatures and clinical factors) were constructed using machine learning software. Univariate logistic regression analysis was performed to identify independent clinical factors. The area under the ROC curve (AUC) was performed to evaluate the performance of three models. A nomogram, decision curves, and calibration curves were used to assess the performance of the combined model.

Results

Six texture features and three independent clinical factors associated significantly with RTLI were used to build the combined model. The AUCs for the combined and radiomics models were 0.962 [95% confidence interval (CI), 0.9306–0.9939] and 0.904 (95% CI, 0.8431–0.9651), respectively, for the training cohort and 0.947 (95% CI, 0.8841–1.0000) and 0.891 (95% CI, 0.7903–0.9930), respectively, for the testing cohort. All of these values exceeded those for the clinics model (AUC = 0.809 and 0.713 for the training and testing cohorts, respectively). Decision curve analysis showed that the combined model had a good corrective effect.

Conclusion

The radiomics–clinics combined model developed in this study showed good performance for predicting RTLI in patients with NPC.

Functional changes of the prefrontal cortex, insula, caudate and associated cognitive impairment (chemobrain) in NSCLC patients receiving different chemotherapy regimen

INTRODUCTION

Chemotherapy-induced cognitive impairment (CICI), termed "chemobrain", is highly prevalent in cancer patients following the administration of chemotherapeutic agents. However, the potential pathophysiological mechanisms underlying CICI remain unknown. This study aimed to explore the functional changes of the brain and associated cognitive impairment in non-small cell lung cancer (NSCLC) patients receiving different chemotherapy regimen.

METHODS

A total of 49 NSCLC patients (25 patients receiving pemetrexed plus carboplatin chemotherapy (PeCC) and 24 patients receiving paclitaxel plus carboplatin chemotherapy (PaCC)) and 61 healthy controls (HCs) were recruited and underwent resting-state functional magnetic resonance imaging (rs-fMRI) scanning, as well as cognitive function tests including Mini Mental State Exam (MMSE), Montreal Cognitive Assessment (MoCA), Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog). Brain functional activities were measured by regional homogeneity (ReHo) values, which were calculated and compared between groups. In addition, the associations between ReHo values of changed brain regions and scores of cognitive scales were evaluated.

RESULTS

NSCLC patients showed decreased scores of MMSE, MoCA and FACT-Cog and decreased ReHo values in the bilateral superior frontal gyrus (medial), middle frontal gyrus, left inferior frontal gyrus (orbital part) and increased ReHo values in the bilateral insula and caudate. Compared with HCs, patients receiving PeCC demonstrated decreased ReHo values in the right superior frontal gyrus (dorsolateral), left superior frontal gyrus (medial orbital), middle frontal gyrus, insula and rectus gyrus while patients receiving PaCC presented increased ReHo values in the right rolandic operculum, left insula and right caudate. Compared with patients receiving PaCC, patients receiving PeCC had decreased ReHo values in the left superior frontal gyrus (orbital part), middle frontal gyrus and increased ReHo values in the left inferior temporal gyrus, lingual gyrus. Moreover, positive relationships were found between ReHo values of the left and right superior frontal gyrus (medial) and the total scores of FACT-Cog in the patient group.

CONCLUSION

The findings provided evidences that carboplatin-based chemotherapy could cause CICI accompanied by functional changes in the prefrontal cortex, insula, caudate. These might be the pathophysiological basis for CICI of NSCLC patients and were affected by the differences of chemotherapeutic agent administration through different biological mechanisms.

Interaction of chemotherapy and radiotherapy in altering the shape of subcortical structures in patients with nasopharyngeal carcinoma

Neuroimaging studies have found significant structural alterations of the cerebral cortex in patients with nasopharyngeal carcinoma (NPC) following radiotherapy (RT) or concomitant chemoradiotherapy (CCRT), while their effects on the shape of subcortical structures remain largely unknown. In this study, we investigated the subcortical shape alterations between three groups: 56 untreated NPC patients (pre-RT group), 37 RT-treated NPC patients (post-RT group), and 108 CCRT-treated NPC patients (post-CCRT group). Using FSL-FIRST, we found that, compared with the pre-RT group, the post-CCRT group exhibited significant inward atrophy in the bilateral thalamus, bilateral putamen, left pallidum, and left caudate and outward inflation in the left caudate, while the post-RT group only exhibited inward atrophy in the bilateral thalamus. In addition, greater maximum dosage of RT for temporal lobes was associated with more severe inward atrophy of the bilateral thalamus in treated NPC patients. These results indicated that there may be an interaction between RT and CT that can cause subcortical damage.

Surface-Based Falff: A Potential Novel Biomarker for Prediction of Radiation Encephalopathy in Patients With Nasopharyngeal Carcinoma

Radiation encephalopathy (RE) is an important potential complication in patients with nasopharyngeal carcinoma (NPC) who undergo radiotherapy (RT) that can affect the quality of life. However, a functional imaging biomarker of pre-symptomatic RE has not yet been established. This study aimed to assess radiation-induced gray matter functional alterations and explore fractional amplitude of low-frequency fluctuation (fALFF) as an imaging biomarker for predicting or diagnosing RE in patients with NPC. A total of 60 patients with NPC were examined, 21 in the pre-RT cohort and 39 in the post-RT cohort. Patients in the post-RT cohort were further divided into two subgroups according to the occurrence of RE in follow-up: post-RT _non-RE (n = 21) and post-RT _{REproved infollow-up} (n = 18). Surface-based and volume-based fALFF were used to detect radiation-induced functional alterations. Functional derived features were then adopted to construct a predictive model for the diagnosis of RE. We observed that surface-based fALFF could sensitively detect radiation-induced functional alterations in the intratemporal brain regions (such as the hippocampus and superior temporal gyrus), as well as the extratemporal regions (such as the insula and prefrontal lobe); however, no significant intergroup differences were observed using volume-based fALFF. No significant correlation between fALFF and radiation dose to the ipsilateral temporal lobe was observed. Support vector machine (SVM) analysis revealed that surface-based fALFF in the bilateral superior temporal gyri and left insula exhibited impressive performance (accuracy = 80.49%) in identifying patients likely to develop RE. We conclude that surface-based fALFF may serve as a sensitive imaging biomarker in the prediction of RE.

Irradiation-related longitudinal white matter atrophy underlies cognitive impairment in patients with nasopharyngeal carcinoma

To longitudinally investigate alterations in cerebral white matter volume as a function of irradiation dose and time after standard radiotherapy in nasopharyngeal carcinoma patients and to determine how these alterations are related to radiotherapy-associated neurocognitive dysfunction.A total of 120 nasopharyngeal carcinoma patients were included in the present study. Longitudinal structural magnetic resonance imaging was performed at pre-radiotherapy and 1-3, 6, and 9-12 months post-radiotherapy. Twenty healthy controls were recruited and followed up with in parallel. Structural images were processed via FreeSurfer. The Montreal Cognitive Assessment was performed to evaluate cognitive function of the participants. Linear mixed models and general linear models were used to evaluate different trajectories and the relationship between white matter volume and cognition in patients and controls within approximately 12 months of follow-up.Selective and time-dependent white matter atrophy was observed in the right parahippocampal gyrus, right inferior temporal gyrus, right middle temporal gyrus, right fusiform gyrus, and left insular cortex in post-radiotherapy patients compared to the controls. Moreover, radiotherapy-associated white matter atrophy in the right parahippocampal gyrus exhibited a dose-dependent pattern, whereas radiotherapy-associated white matter atrophy in the right inferior temporal gyrus was correlated with progressive cognitive impairment in patients.Taken together, our findings illustrate that white matter volume alterations can be used as a potential biomarker to detect radiotherapy-related subtle brain injury in nasopharyngeal carcinoma patients, which may help further elucidate the pathogenesis of radiation-induced cognitive decline and facilitate studies on cognition-sparing radiotherapy.