Microstructural white matter alterations associated to neurocognitive deficits in childhood leukemia survivors treated with cranial radiotherapy - a diffusional kurtosis study

Radiotherapy for central neurocytoma: A multicentric retrospective study in France

PURPOSE

Neurocytomas represent 0.25 to 0.5% of primary brain tumours and are mainly found in young adults. These tumours have neuronal differentiation. The cornerstone treatment is neurosurgery. The efficacy of other therapies, including radiotherapy, is still unclear. The objective of this study was to evaluate the management of central neurocytomas and the role of radiotherapy.

MATERIALS AND METHODS

All adult patients (age 18 years or older) newly diagnosed with a histologically confirmed neurocytoma between 2006 and 2015 in France were included.

RESULTS

One hundred and sixteen patients were diagnosed with a central neurocytoma during the study period. All patients underwent surgical resection, and six received adjuvant radiotherapy. Eleven patients received radiotherapy due to progression. After a median follow-up of 68.7 months, local failure occurred in 29 patients. The 5-year local control rate was 73.4%. According to univariate analysis, marker of proliferation Ki67 index greater than 2% (hazard ratio [HR]: 1.48; confidence interval [CI]: 1.40-1.57; P=0.027) and subtotal resection (HR: 8.48; CI: 8.01-8.99; P<0.001) were associated with an increase in local failure. Gross total resection was associated with a higher risk of sequelae epilepsy (HR: 3.62; CI: 3.42-3.83; P<0.01) and memory disorders (HR: 1.35; CI: 1.07-1.20; P<0.01). Ten patients (8.6%) died during the follow-up. The 10-year overall survival rate was 89.0%. No prognostic factors for overall survival were found.

CONCLUSION

The analysis showed that patients who underwent subtotal surgical resection, particularly when the tumour had a Ki67 index greater than 2%, had an increased risk of local recurrence. These patients could benefit from adjuvant radiotherapy.

Diffusion kurtosis imaging of brain white matter alteration in patients with coronary artery disease based on the TBSS method

Object

The aim of our study was to examine the alterations in microstructure in patients with coronary artery disease (CAD) and cognitive impairment (CI) using diffusion kurtosis imaging (DKI). Additionally, we aimed to investigate the potential correlation between DKI parameters and cognitive function.

Materials and methods

A total of 28 CAD patients and 30 healthy controls (HC) were prospectively enrolled in our study. All participants underwent routine and diffusion sequences of head imaging. DKE software was utilized to generate various diffusion kurtosis imaging parameters (DKI), including kurtosis fractional anisotropy (KFA), mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), fractional anisotropy (FA), and mean diffusivity (MD). Nonparametric tests were conducted using tract-based spatial statistics (TBSS) to compare the parameter values between the two groups. The parameter values of the significantly different fiber tracts were extracted and correlated with the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores.

Results

Compared to the HC group, patients with coronary artery disease exhibited significant reductions in FA values in the bilateral Superior corona radiata, bilateral Anterior corona radiata, bilateral Posterior corona radiata, corpus callosum, left Posterior thalamic radiation, right Posterior limb of internal capsule, Anterior limb of internal capsule, and Cerebral peduncle, as well as in the left Superior longitudinal fasciculus. Additionally, KFA values decreased in the bilateral Anterior corona radiata, bilateral Anterior limb of internal capsule, and Genu of the corpus callosum. The MK values decreased in the right Posterior corona radiata, Retrolenticular part of the internal capsule, Posterior thalamic radiation (including optic radiation), Superior longitudinal fasciculus, and left Posterior thalamic radiation (including optic radiation). Moreover, the RK values decreased in the bilateral Retrolenticular part of the internal capsule, right Posterior thalamic radiation (including optic radiation), and Superior longitudinal fasciculus, as well as in the left Superior longitudinal fasciculus and Posterior thalamic radiation (including optic radiation) (p < 0.01, TFCE corrected), while no significant differences were observed in other parameter values (p > 0.01, TFCE corrected). The FA values of the right posterior limb of the internal capsule (r = 0.610, p = 0.001) and the right cerebral peduncle (r = 0.622, p < 0.001) were positively correlated with MMSE scores. Additionally, a significant correlation between kurtosis and diffusion coefficient parameters (FA and KFA) was observed.

Conclusion

CAD patients showed radial shrinkage and complexity of brain white matter microstructure. Whole-brain white matter analysis based on TBSS DKI can objectively reflect the characteristics of white matter damage in CAD patients, providing a basis for the auxiliary diagnosis of CAD with CI.

Methylphenidate improves cognitive function and health-related quality of life in survivors of childhood brain tumours

OBJECTIVES

The growing population of survivors of childhood brain tumors present the challenge of long-term quality of survival. The domains most affected by tumor and treatment are those implicated in development of typical intellectual functions: attention, working memory, and processing speed, with consequent effects upon function and quality of life. In this paper we present service evaluation data on the 12-month effect upon processing speed, visual and auditory attentional domains in 29 patients receiving methylphenidate aged 5-16 years (Mean=10.6).

METHODS

Patients received immediate-release methylphenidate and were converted to modified-release as appropriate. Mean optimal dose of immediate-release methylphenidate was 0.34 mg/kg per dose (range 0.2-0.67).

RESULTS

Patients showed a significant positive impact of methylphenidate on attention in all tests of selective visual attention from the Test of Everyday Attention for Children 2. A significant improvement was also shown on response time. Significant change was not found on psychometric measures of sustained auditory or visual attention, or selective auditory attention. Ratings of Health-Related Quality of Life showed a positive benefit of methylphenidate at 12 months. Side effects were minimal and not statistically significant.

CONCLUSIONS

Survivors of childhood brain tumor with attentional and processing speed deficit show clinical benefit from methylphenidate.

[Recent research on cognitive impairment in children with acute lymphoblastic leukemia]

Acute lymphoblastic leukemia (ALL) is the most common malignant neoplastic disease in children. With the continuous improvement in diagnosis and treatment, there has been an increasing number of ALL children who achieve long-term survival after complete remission; however, a considerable proportion of these children have cognitive impairment, which has a serious adverse impact on their learning, employment, and social life. This article reviews the latest research on cognitive impairment in children with ALL from the aspects of the influencing factors, detection techniques, and prevention/treatment methods for cognitive impairment.

Neurocognitive and radiological changes after cranial radiation therapy in humans and rodents: a systematic review

BACKGROUND

Radiation-induced brain injury is a common long-term side effect for brain cancer survivors, leading to a reduced quality of life. Although there is growing research pertaining to this topic, the relationship between cognitive and radiologically detected lesions of radiation-induced brain injury in humans remains unclear. Furthermore, clinically translatable similarities between rodent models and human findings are also undefined. The objective of this review is to then identify the current evidence of radiation-induced brain injury in humans and to compare these findings to current rodent models of radiation-induced brain injury.

METHODS

This review includes an examination of the current literature on cognitive and radiological characteristics of radiation-induced brain injury in humans and rodents. A thorough search was conducted on PubMed, Web of Science, and Scopus to identify studies that performed cognitive assessments and magnetic resonance imaging techniques on either humans or rodents after cranial radiation therapy. A qualitative synthesis of the data is herein reported.

RESULTS

A total of 153 studies pertaining to cognitively or radiologically detected radiation injury of the brain are included in this systematic review; 106 studies provided data on humans while 47 studies provided data on rodents. Cognitive deficits in humans manifest across multiple domains after brain irradiation. Radiological evidence in humans highlight various neuroimaging-detectable changes post-irradiation. It is unclear, however, whether these findings reflect ground truth or research interests. Additionally, rodent models do not comprehensively reproduce characteristics of cognitive and radiological injury currently identified in humans.

CONCLUSION

This systematic review demonstrates that associations between and within cognitive and radiological radiation-induced brain injuries often rely on the type of assessment. Well-designed studies that evaluate the spectrum of potential injury are required for a precise understanding of not only the clinical significance of radiation-induced brain injury in humans, but also how to replicate injury development in pre-clinical models.

Dose-dependent early white matter alterations in patients with brain metastases after radiotherapy

PURPOSE

Previous diffusion tensor imaging (DTI) studies have mainly focused on dose-dependent white matter (WM) alterations 1 month to 1 year after radiation therapy (RT) with a tract-average method. However, WM alterations immediately after RT are subtle, resulting in early WM alterations that cannot be detected by tract-average methods. Therefore, we performed a study with an along-tract method in patients with brain metastases to explore the early dose-response pattern of WM alterations after RT.

METHODS

Sixteen patients with brain metastases underwent DTI before and 1-3 days after brain RT. DTI metrics, such as fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD) and mean diffusivity (MD), were calculated. Along-tract statistics were then used to resample WM fibre streamlines and generate a WM skeleton fibre tract. DTI metric alterations (post_RT-pre_RT DTI metrics) and the planned doses (max or mean doses) were mapped to 18 WM tracts. A linear fixed model was performed to analyse the main effect of dose on DTI metric alterations.

RESULTS

AD alterations in the left hemispheric uncinated fasciculus (UNC_L) were associated with max doses, in which decreased AD alterations were associated with higher doses.

CONCLUSION

Our findings may provide pathological insight into early dose-dependent WM alterations and may contribute to the development of max dose-constrained RT techniques to protect brain microstructure in the UNC_L.

Cranial MRI in Childhood Acute Leukemia during Treatment and Follow-Up Including the Impact of Intrathecal MTX-A Single-Center Study and Review of the Literature

Due to high survival rates, long-term sequelae, especially neurotoxicity, need to be considered in childhood acute leukemias. In this retrospective analysis of morphologic changes of the brain in children treated for acute leukemias, we included 94 patients (77 ALL, 17 AML; 51 male, 43 female; median age: 5 years) from a single center. We analyzed 170 cranial MRI scans (T2, FLAIR axial) for morphologic alterations of the brain and variations of the ventricular width (GDAH). In addition, the corresponding literature was reviewed. More than 50% of all patients showed cerebral pathomorphologies (CP). They were seen more often in children with ALL (55.8%), ≤ 6 years of age (60.8%), in relapse (58.8%) or after CNS irradiation (75.0%) and included white matter changes, brain atrophy, sinus vein thrombosis and ischemic events. GDAH significantly enlarged mainly in children up to 6 years, with relapse, high-risk leukemias or ALL patients. However, GDAH can normalize again. The number of intrathecal Methotrexate applications (≤12 vs. >12) showed no correlation to morphologic alterations besides a significant increase in GDAH (−0.3 vs. 0.9 mm) between the first and last follow-up MRI in ALL patients receiving >12 ith. MTX applications. The role of ith. MTX on CP needs to be further investigated and correlated to the neurocognitive outcome of children with acute leukemias.

Diffusion tensor imaging indices as biomarkers for cognitive changes following paediatric radiotherapy: a systematic review and meta-analysis

Diffusion tensor imaging (DTI) can detect subtle manifestations of white matter (WM) injury following paediatric radiotherapy, which may be a potential biomarker for cognitive changes. This study aimed to synthesise the relationships between DTI indices and cognitive changes following paediatric radiotherapy through systematic review and meta-analysis. PubMed and Scopus electronic databases were used to identify eligible studies. Quality assessment was performed using the National Institute of Health (NIH) Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Information on demographics, DTI changes, and associations to cognitive outcomes were extracted. Meta-analyses were performed on DTI changes in specific anatomical locations. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed in the preparation of this report. Eighteen studies were included (median study size: 21; range 18-146). 17/18 studies showed significant cognitive decline following irradiation. Meta-analyses found significant cognitive changes within patient's group of acute lymphoblastic leukaemia (ALL; standard mean differences [SMD] = -0.075, P = 0.01) and brain tumours (BT; SMD = -1.037, P ≤ 0.001) compared to control/baseline. Both groups also had significantly lower fractional anisotropy (FA) scores in the corpus callosum (ALL: SMD = -0.979, P = 0.002; BT: SMD = -1.025, P < 0.001). Decreased FA was consistently associated with cognitive decline. Correlation on WMFA integrity to cognitive domains was statistically significant (Z = 9.86, P < 0.001) with a large effect size (r = 0.52). White matter tract integrity of the corpus callosum measured with FA has the potential to be a biomarker for radiotherapy-related cognitive decline. Inclusion of DTI in follow-up imaging should be encouraged.

Cognitive interference processing in adult survivors of childhood acute lymphoblastic leukemia using functional magnetic resonance imaging

BACKGROUND

Childhood acute lymphoblastic leukemia (ALL) is associated with cognitive impairment in adulthood. Cognitive interference processing and its correlated functional magnetic resonance imaging (fMRI) activity in the brain have not yet been studied in this patient group.

MATERIAL

Twenty-six adult childhood ALL survivors (median [interquartile range {IQR}] age, 40.0 [37.0-42.3] years) were investigated at median age (IQR), 35.0 (32.0-37.0) years after treatment with intrathecal and intravenous chemotherapy as well as cranial radiotherapy (24 Gy) and compared with 26 matched controls (median [IQR] age, 37.5 [33.0-41.5] years).

METHODS

Cognitive interference processing was investigated in terms of behavioral performance (response times [ms] and accuracy performance [%]) and fMRI activity in the cingulo-fronto-parietal (CFP) attention network as well as other parts of the brain using the multisource interference task (MSIT).

RESULTS

ALL survivors had longer response times and reduced accuracy performance during cognitive interference processing (median [IQR] interference effect, 371.9 [314.7-453.3] ms and 6.7 [4.2-14.7]%, respectively) comparedwith controls (303.7 [275.0-376.7] ms and 2.3 [1.6-4.3]%, respectively), but did not exhibit altered fMRI activity in the CFP attention network or elsewhere in the brain.

CONCLUSION

Adult childhood ALL survivors demonstrated impaired behavioral performance but no altered fMRI activity when performing cognitive interference processing when compared with controls. The results can be used to better characterize this patient group and to optimize follow-up care and support for these individuals.

Early-Onset Micromorphological Changes of Neuronal Fiber Bundles During Radiotherapy

BACKGROUND

Patients receiving cranial radiation face the risk of delayed brain dysfunction. However, an early medical imaging marker is not available until irreversible morphological changes emerge.

PURPOSE

To explore the micromorphological white matter changes during the radiotherapy session by utilizing an along-tract analysis framework.

STUDY TYPE

Prospective.

POPULATION

Eighteen nasopharyngeal carcinoma (two female) patients receiving cranial radiation.

FIELD STRENGTH/SEQUENCE

3.0 T; Diffusion tensor imaging (DTI) and T1- and T2-weighted images (T1W, T2W); computed tomography (CT).

ASSESSMENT

Patients received three DTI imaging scans during the radiotherapy (RT), namely the baseline scan (1-2 days before RT began), the middle scan (the middle of the RT session), and the end scan (1-2 days after RT ended). Twelve fibers were segmented after whole-brain tractography. Then, the fractional anisotropy (FA) values and the cumulative radiation dose received for each fiber streamline were resampled and projected into their center fiber.

STATISTICAL TESTS

The contrast among the three scans (P1: middle scan-baseline scan; P2: end scan-middle scan; P3: end scan-baseline scan) were compared using the linear mixed model for each of the 12 center fibers. Then, a dose-responsiveness relationship was performed using Pearson correlation. P < 0.05 was considered statistically significant.

RESULTS

Six of the 12 center fibers showed significant changes of FA values during the RT but with heterogeneous patterns. The significant changes along a specific center fiber were associated with their cumulative dose received (Genu: P1 r = -0.6182, P2 r = -0.5907; Splenium: P1 r = 0.4055, P = 0.1063, P2 r = 0.6742; right uncinate fasciculus: P1 r = -0.3865, P2 r = -0.4912, P = 0.0533; right corticospinal tract: P1 r = 0.4273, P = 0.1122, P2 r = -0.6885).

DATA CONCLUSION

The along-tract analysis might provide sensitive measures on the early-onset micromorphological changes.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 3.

Brain Microstructural Changes Associated With Neurocognitive Outcome in Intracranial Germ Cell Tumor Survivors

Background

Childhood intracranial germ cell tumor (GCT) survivors are prone to radiotherapy-related neurotoxicity, which can lead to neurocognitive dysfunctions. Diffusion kurtosis imaging (DKI) is a diffusion MRI technique that is sensitive to brain microstructural changes. This study aimed to investigate the association between DKI metrics versus cognitive and functional outcomes of childhood intracranial GCT survivors.

Methods

DKI was performed on childhood intracranial GCT survivors (n = 20) who had received cranial radiotherapy, and age and gender-matched healthy control subjects (n = 14). Neurocognitive assessment was performed using the Hong Kong Wechsler Intelligence Scales, and functional assessment was performed using the Lansky/Karnofsky performance scales (KPS). Survivors and healthy controls were compared using mixed effects model. Multiple regression analyses were performed to determine the effects of microstructural brain changes of the whole brain as well as the association between IQ and Karnofsky scores and the thereof.

Results

The mean Intelligence Quotient (IQ) of GCT survivors was 91.7 (95% CI 84.5 – 98.8), which was below the age-specific normative expected mean IQ (P = 0.013). The mean KPS score of GCT survivors was 85.5, which was significantly lower than that of controls (P < 0.001). Cognitive impairments were significantly associated with the presence of microstructural changes in white and grey matter, whereas functional impairments were mostly associated with microstructural changes in white matter. There were significant correlations between IQ versus the mean diffusivity (MD) and mean kurtosis (MK) of specific white matter regions. The IQ scores were negatively correlated with the MD of extensive grey matter regions.

Conclusion

Our study identified vulnerable brain regions whose microstructural changes in white and grey matter were significantly associated with impaired cognitive and physical functioning in survivors of pediatric intracranial GCT.

The association between White matter microstructure alterations detected by Diffusional kurtosis imaging in Neural circuit and post-stroke depression

AIM

In order to study the mechanism of post-stroke depression (PSD), we used diffusion kurtosis imaging (DKI) to describe the changes in white matter (WM) microstructure in PSD patients, to investigate the association between WM damage in limbic-cortical-striatal-pallidal-thalamic (LCSPT) circuit and PSD, and the utility of DKI in the diagnosis of PSD.

METHODS

Fifty-eight participants were divided into different groups: control group (n=20), stroke patients without depression (Non-PSD, n=21) and PSD group (n=17). All were taken DKI scans. The WM of bilateral superior frontal gyrus, middle frontal gyrus, inferior frontal gyrus, temporal lobe, parietal lobe, occipital lobe, the anterior and posterior limb of internal capsule, the genu and splenium of corpus callosum were selected as the regions of interest (ROI) and selected mean kurtosis (MK), radial kurtosis (RK), axial kurtosis (AK) as the DKI parameters.

RESULTS

Compared with control and Non-PSD, MK of PSD group in bilateral superior frontal gyrus, middle frontal gyrus, temporal lobe and the genu of corpus callosum were decreased significantly, as well as the RK in left superior frontal gyrus, bilateral middle frontal gyrus and temporal lobe. But there was no significant difference in AK. Besides, the decrease in MK and RK in frontal and temporal lobe was negatively associated with the severity of PSD.

CONCLUSION

Our research indicated that the damage to WM microstructure in the frontal lobe, temporal lobe and the genu of corpus callosum may be related toPSD. DKI explores the microstructural changes of WM in PSD patients and may be an auxiliary diagnostic method for PSD.

White matter alterations in adult with autism spectrum disorder evaluated using diffusion kurtosis imaging

PURPOSE

Autism spectrum disorder (ASD) is related to impairment in various white matter (WM) pathways. Utility of the recently developed two-compartment model of diffusion kurtosis imaging (DKI) to analyse axial diffusivity of WM is restricted by several limitations. The present study aims to validate the utility of model-free DKI in the evaluation of WM alterations in ASD and analyse the potential relationship between DKI-evident WM alterations and personality scales.

METHODS

Overall, 15 participants with ASD and 15 neurotypical (NT) controls were scanned on a 3 T magnetic resonance (MR) scanner, and scores for autism quotient (AQ), systemising quotient (SQ) and empathising quotient (EQ) were obtained for both groups. Multishell diffusion-weighted MR data were acquired using two b-values (1000 and 2000 s/mm²). Differences in mean kurtosis (MK), radial kurtosis (RK) and axial kurtosis (AK) between the groups were evaluated using tract-based spatial statistics (TBSS). Finally, the relationships between the kurtosis indices and personality quotients were examined.

RESULTS

The ASD group demonstrated significantly lower AK in the body and splenium of corpus callosum than the NT group; however, no other significant differences were identified. Negative correlations were found between AK and AQ or SQ, predominantly in WM areas related to social-emotional processing such as uncinate fasciculus, inferior fronto-occipital fasciculus, and inferior and superior longitudinal fasciculi.

CONCLUSIONS

Model-free DKI and its indices may represent a novel, objective method for detecting the disease severity and WM alterations in patients with ASD.