Chemotherapy-only Protocols Research Articles

Changed cortical thickness and sulcal depth in pediatric acute lymphoblastic leukemia survivors treated with chemotherapy only.

The purpose of this study is to observe the changes of cortical morphological characteristics and their potential contribution to cognitive function in ALL survivors by using surface-based morphometry (SBM). Using SBM analysis, we calculated and compared group differences in cortical thickness, sulcal depth, gyrification, and fractal dimension of the cerebral cortex between 18 pediatric ALL survivors treated on chemotherapy-only protocols and off treatment within 2years, and 18 healthy controls (HCs) with two-sample t-tests [P < 0.05, family-wise error (FWE) corrected]. Relationships between abnormal cortical characteristic values and cognitive function parameters were investigated with partial correlation analysis, taking age as a covariate. We found decreased cortical thickness mainly located in the prefrontal and temporal region, and increased sulcal depth in left rostral middle frontal cortex and left pars orbitalis in the ALL survivors compared to HCs. There were no statistically significant differences in the gyrification and fractal dimension between the two groups. In ALL survivors, cortical thickness and sulcal depth of above areas values revealed no significant correlation with the cognitive function parameters. In conclusion, pediatric ALL survivors show decreased cortical thickness in prefrontal and temporal regions, and increased sulcal depth in prefrontal region. These results suggest that SBM-based approach can be used to assess changes of cortical morphological characteristics in pediatric ALL survivors.

Structural and Functional Brain Imaging in Long-Term Survivors of Childhood Acute Lymphoblastic Leukemia Treated With Chemotherapy: A Systematic Review.

BackgroundThe effect of chemotherapy on brain development in long-term survivors of pediatric acute lymphoblastic leukemia (ALL) was systematically reviewed.MethodsA systematic search of Pubmed, Scopus, and PsycINFO databases was conducted to identify articles published between January 2000 and February 2020 that implemented magnetic resonance imaging to assess brain structure and function in pediatric ALL survivors (diagnosed younger than 21 years of age). The review included articles that were published on children diagnosed with ALL between 0 and 21 years of age and treated with chemotherapy-only protocols. Articles meeting the inclusion criteria described survivors on average of 5 years or more from diagnosis and were peer-reviewed articles and original studies.ResultsThe search yielded 1975 articles with 23 articles meeting inclusion criteria. The review revealed that survivors had statistically significant alterations in brain anatomy, most commonly a smaller hippocampus and impaired microstructural white matter integrity in frontal brain regions. Survivors also had impaired brain function including lower brain network efficiency and altered resting state connectivity. Survivors also displayed widespread reductions in brain activation (ie, frontal, temporal, parietal brain regions) during cognitive tasks.ConclusionAlthough the neurotoxic effects of cancer treatment are reduced in the absence of cranial radiation, survivors treated on chemotherapy-only protocols still display long-term alterations in brain structure and function, which contribute to lifelong neurocognitive late effects.

Connectivity of the Cerebello-Thalamo-Cortical Pathway in Survivors of Childhood Leukemia Treated With Chemotherapy Only

Treatment with contemporary chemotherapy-only protocols is associated with risk for neurocognitive impairment among survivors of childhood acute lymphoblastic leukemia (ALL). To determine whether concurrent use of methotrexate and glucocorticoids is associated with interference with the antioxidant system of the brain and damage and disruption of glucocorticoid-sensitive regions of the cerebello-thalamo-cortical network. This cross-sectional study was conducted from December 2016 to July 2019 in a single pediatric cancer tertiary care center. Participants included survivors of childhood ALL who were more than 5 years from cancer diagnosis, age 8 years or older, and treated on an institutional chemotherapy-only protocol. Age-matched community members were recruited as a control group. Data were analyzed from August 2017 to August 2020. ALL treatment using chemotherapy-only protocols. This study compared brain volumes between survivors and individuals in a community control group and examined associations among survivors of methotrexate and dexamethasone exposure with neurocognitive outcomes. Functional and effective connectivity measures were compared between survivors with and without cognitive impairment. The Rey-Osterrieth complex figure test, a neurocognitive evaluation in which individuals are asked to copy a figure and then draw the figure from memory, was scored according to published guidelines and transformed into age-adjusted z scores based on nationally representative reference data and used to measure organization and planning deficits. β values for neurocognitive tests represented the amount of change in cerebellar volume or chemotherapy exposure associated with 1 SD change in neurocognitive outcome by z score (mm3/1 SD in z score for cerebellum, mm3/[g×hr/L] for dexamethasone and methotrexate AUC, and mm3/intrathecal count for total intrathecal count). Among 302 eligible individuals, 218 (72%) participated in the study and 176 (58%) had usable magnetic resonance imaging (MRI) results. Among these, 89 (51%) were female participants and the mean (range) age was 6.8 (1-18) years at diagnosis and 14.5 (8-27) years at evaluation. Of 100 community individuals recruited as the control group, 82 had usable MRI results; among these, 35 (43%) were female individuals and the mean (range) age was 13.8 (8-26) years at evaluation. There was no significant difference in total brain volume between survivors and individuals in the control group. Survivors of both sexes showed decreased mean (SD) cerebellar volumes compared with the control population (female: 70 568 [6465] mm3 vs 75 134 [6780] mm3; P < .001; male: 77 335 [6210] mm3 vs 79 020 [7420] mm3; P < .001). In female survivors, decreased cerebellar volume was associated with worse performance in Rey-Osterrieth complex figure test (left cerebellum: β = 55.54; SE = 25.55; P = .03; right cerebellum: β = 52.57; SE = 25.50; P = .04) and poorer dominant-hand motor processing speed (ie, grooved pegboard performance) (left cerebellum: β = 82.71; SE = 31.04; P = .009; right cerebellum: β = 91.06; SE = 30.72; P = .004). In female survivors, increased number of intrathecal treatments (ie, number of separate injections) was also associated with Worse Rey-Osterrieth test performance (β = -0.154; SE = 0.063; P = .02), as was increased dexamethasone exposure (β = -0.0014; SE = 0.0005; P = .01). Executive dysfunction was correlated with increased global efficiency between smaller brain regions (Pearson r = -0.24; P = .01) compared with individuals without dysfunction. Anatomical connectivity showed differences between impaired and nonimpaired survivors. Analysis of variance of effective-connectivity weights identified a significant interaction association (F = 3.99; P = .02) among the direction and strength of connectivity between the cerebellum and DLPFC, female sex, and executive dysfunction. Finally, no effective connectivity was found between the precuneus and DLPFC in female survivors with executive dysfunction. These findings suggest that dexamethasone exposure was associated with smaller cerebello-thalamo-cortical regions in survivors of ALL and that disruption of effective connectivity was associated with impairment of executive function in female survivors.

Quantitative MRI outcomes in child and adolescent leukemia survivors: Evidence for global alterations in gray and white matter

IntroductionCure rates for pediatric acute lymphoblastic leukemia (ALL) have reached an all-time high (>90%); however, neurocognitive difficulties continue to affect quality of life in at least a subset of survivors. There are relatively few quantitative neuroimaging studies in child and adolescent ALL survivors treated with chemotherapy only. Use of different outcome measures or limited sample sizes restrict our ability to make inferences about patterns of brain development following chemotherapy treatment. In this study, we used magnetic resonance imaging (MRI) to evaluate brain outcomes in ALL survivors, comparing against a group of typically developing, cancer free peers. Materials and methodsParticipants included 71 ALL survivors, on average 8 years after diagnosis and 8–18 years of age, and 83 typically developing controls. Anatomical MRI was performed to evaluate brain structure; diffusion and magnetization transfer MRI were used to examine brain tissue microstructure. ResultsSuccessful MRI scans were acquired in 67 survivors (94%) and 82 controls (99%). Structurally, ALL survivors exhibited widespread reductions in brain volume, with 6% less white matter and 5% less gray matter than controls (p = 0.003 and 0.0006 respectively). Much of the brain appeared affected – 71 of 90 evaluated structures showed smaller volume – with the most notable exception being the occipital lobe, where no significant differences were observed. Average full-scale IQ in the survivor and control groups were 95 (CI 92–99) and 110 (CI 107–113), respectively. Using data from the NIH Pediatric MRI Data Repository, we evaluated the extent to which elevated IQ in the control group might affect the structural differences observed. We estimated that two thirds of the observed brain differences were attributable to ALL and its treatment. In addition to the structural changes, survivors showed, on average, globally lower white matter fractional anisotropy (-3%) and higher radial diffusivity (+5%) (p < 10−6), but no differences in magnetization transfer ratio. ConclusionsNeuroanatomical alterations in late childhood and adolescent ALL survivors treated with chemotherapy-only protocols are widespread, with white matter being somewhat more affected than gray matter. These MRI results indicate brain development is altered in ALL survivors and highlight the need to examine how these alterations emerge.

Subcortical brain volumes and neurocognitive function in survivors of childhood acute lymphoblastic leukemia (ALL) treated with chemotherapy-only.

10517 Background: Brain deep grey nuclei and glucocorticoid receptor rich hippocampal subregions may be sensitive to neurotoxic effects of chemotherapy-only protocols for childhood ALL and associated with neurocognitive problems in long-term survivors. Methods: Brain MRIs and neurocognitive tests were obtained on 176 survivors (49% male, mean [range] age at diagnosis 6.8 [1-18] years, 14.5 [8-27] years at evaluation). MRI’s were also obtained on 82 healthy community controls (57% male, 13.8 [8-26] years at evaluation). General linear models were used to compare subcortical brain volumes between survivors and controls. Among survivors, gender stratified multivariable linear models were used to test associations between subcortical volumes, and serum concentration of dexamethasone (DEX) and high-dose methotrexate (HDMTX), adjusting for age at diagnosis, and intracranial volume (ICV). Volumes were also compared to neurocognitive tests. Results: Survivors had smaller volumes in bilateral thalami (p’s &lt; 0.05) and hippocampal subregions (p’s &lt; 0.001) compared to controls. After controlling for ICV, HDMTX exposure and younger age at diagnosis were associated with smaller bilateral thalami in male survivors (p’s &lt; 0.05). DEX was associated with a smaller right thalamus in males (p = 0.04). Smaller hippocampi in both males and females were associated with younger age at diagnosis (p’s &lt; 0.01). Smaller left thalamus was associated with worse verbal fluency scores in all survivors (p’s &lt; 0.05). Smaller bilateral thalami and hippocampal subregions in girls were associated with worse processing speed, inhibition and cognitive flexibility; poor memory span correlated with smaller left CA1 and right thalamus volumes (all p’s &lt; 0.05). Smaller bilateral thalami and right hippocampal subregions, in girls, correlated with slower processing speed (p’s &lt; 0.05). In males, smaller left fimbria volume was correlated with poor attention (p = 0.03). Conclusions: ALL survivors have significantly smaller thalamic and hippocampal volumes compared to healthy community controls. In survivors, smaller volumes correlate with worse cognitive performance.

The relationship between cognitive and neuroimaging outcomes in children treated for acute lymphoblastic leukemia with chemotherapy only: A systematic review.

Cognitive late-effects have been identified in patients treated with chemotherapy-only protocols for childhood acute lymphoblastic leukemia (ALL), yet the underlying neuropathology is not well understood. This review synthesized recent findings from eight articles investigating the relationship between neurocognitive and neuroimaging outcomes for patients treated for ALL with chemotherapy-only protocols. Reported cognitive domains, imaging methods, and neuroanatomy examined were variable. Despite this, 62.5% (n = 5) of the reviewed studies found a significant relationship between cognitive and imaging outcomes. Greater understanding of the effects of treatment on neuroanatomy and cognitive outcomes is critical for proactively managing ALL cognitive late-effects. Research directions are suggested.

Chemotherapy Pharmacodynamics and Neuroimaging and Neurocognitive Outcomes in Long-Term Survivors of Childhood Acute Lymphoblastic Leukemia.

To examine associations among methotrexate pharmacodynamics, neuroimaging, and neurocognitive outcomes in long-term survivors of childhood acute lymphoblastic leukemia treated on a contemporary chemotherapy-only protocol. This longitudinal study linked pharmacokinetic assays collected during therapy to neurocognitive and brain imaging outcomes during long-term follow-up. A total of 218 (72.2%) of 302 eligible long-term survivors were recruited for outcome studies when they were more than 5 years post-diagnosis and older than 8 years of age. At long-term follow-up, survivors were an average of 13.8 years old and 7.7 years from diagnosis, and 51% were male. Neurocognitive testing, functional magnetic resonance imaging (MRI) during an executive function task, and structural MRI with diffusion tensor imaging were conducted. Generalized linear models were developed to identify predictors, and models were adjusted for age at diagnosis, sex, and parent education. Intelligence was within normal limits (mean, 98; standard deviation, 14) compared with population expectations (mean, 100; standard deviation, 15), though measures of executive function, processing speed, and memory were less than population means (all P < .02 after correction for false discovery rates). Higher plasma concentration of methotrexate was associated with a poorer executive function score (P < .02). Higher plasma methotrexate was also associated with higher functional MRI activity, with thicker cortices in dorsolateral prefrontal brain regions, and with white matter microstructure in the frontostriatal tact. Neurocognitive impairment was associated with these imaging findings as well. Associations did not change after adjustment for age or dose of leucovorin rescue. Survivors of childhood acute lymphoblastic leukemia treated on contemporary chemotherapy-only protocols demonstrate executive dysfunction. A higher plasma concentration of methotrexate was associated with executive dysfunction as well as with a thicker cortex and higher activity in frontal brain regions, regions often associated with executive function.

Late psychiatric morbidity in survivors of cancer at a young age: a nationwide registry-based study.

Childhood cancer survivors have been shown to be prone to psychosocial adverse outcomes. Data on young adults and their psychiatric late effects are still scarce. In a nationwide, registry-based study, we explored the risk (HR) of new psychiatric diagnoses in 5-year survivors of childhood and young adulthood (YA) cancer (n = 13,860) compared with a sibling cohort (n = 43,392). Hazard ratios (HRs) were calculated using Cox regression models. Patients and siblings were identified from the Finnish Cancer Registry and Central Population Registry, respectively. Outcome diagnoses were retrieved from the national hospital discharge register. The risk of organic memory/brain disorders was significantly increased in both childhood (HR 4.9; 95%CI 2.7-8.9) and YA (HR 2.1; 95%CI 1.4-3.1) cancer survivors compared with siblings. Mood disorders were also more common in childhood (HR 1.3; 95%CI 1.1-1.7) and YA survivors (1.3; 95%CI 1.1-1.5) than in siblings. Radiotherapy did not explain the differences. Female childhood cancer survivors had significantly increased HRs for mood disorders, psychotic disorders, neurotic/anxiety disorders, somatization/eating disorders and personality disorders. In survivors of YA cancers, females had significantly increased HR for neurotic/anxiety disorders, and the difference between female survivors and siblings was significantly (p < 0.05) higher than that between male survivors and male siblings. The effect of treatment era was also analyzed, and the risk of organic memory and brain disorders in childhood cancer survivors did not diminish over time. Despite the trend of decreased use of cranial irradiation in children, the risk of organic memory/brain disorders was elevated, even during the most recent era. Thus, additional research on chemotherapy-only protocols and their impact on mental health, is warranted.

Neurocognitive late effects of chemotherapy in children: The past 10 years of research on brain structure and function

Advances in the treatment of childhood cancers have greatly improved survivorship. Success has not come without cost, however, as survivors are at risk for late effects of treatment, including neurocognitive late effects (e.g., difficulties with thinking and reasoning). In the advent of chemotherapy-only protocols, researchers are examining neurocognitive sequelae of these agents to understand the specific role of chemotherapy in neurocognitive changes and the mechanism through which these occur. In this review, we examine the state of the literature on neurocognitive late effects after chemotherapy and their proposed neural mechanisms.

Comparison of Long-Term Neurocognitive Outcomes in Young Children With Acute Lymphatic Leukemia Treated With Cranial Radiation or High-Dose or Very High-Dose Intravenous Methotrexate

Purpose Cranial radiation therapy (CRT) is associated with neurocognitive morbidity in survivors of childhood acute lymphoblastic leukemia (ALL). For most patients, CRT has been replaced with intensified systemic and intrathecal chemotherapy, often including methotrexate (MTX). The impact of chemotherapy-only protocols on neurocognitive outcomes is unclear, and the importance of systemic MTX dose has not been established. Patients and Methods Seventy nine of 120 eligible children diagnosed with high-risk ALL between the ages of 1.0 and 4.9 years participated in this retrospective cohort study. All patients were treated on a uniform chemotherapy protocol with one of three modalities of CNS prophylaxis, depending on their treatment era. In addition to intrathecal therapy, CNS-directed therapy consisted of CRT (18 Gy in 10 fractions) in 25 patients, high-dose intravenous (IV) MTX (8 g/m2 × 3 doses) in 32 patients and very high-dose IV MTX (33.6 g/m2 x 3 doses) in 22 patients. Participants completed tests of ...

Comparison of Long-Term Neurocognitive Outcomes in Young Children With Acute Lymphoblastic Leukemia Treated With Cranial Radiation or High-Dose or Very High-Dose Intravenous Methotrexate

Cranial radiation therapy (CRT) is associated with neurocognitive morbidity in survivors of childhood acute lymphoblastic leukemia (ALL). For most patients, CRT has been replaced with intensified systemic and intrathecal chemotherapy, often including methotrexate (MTX). The impact of chemotherapy-only protocols on neurocognitive outcomes is unclear, and the importance of systemic MTX dose has not been established. Seventy nine of 120 eligible children diagnosed with high-risk ALL between the ages of 1.0 and 4.9 years participated in this retrospective cohort study. All patients were treated on a uniform chemotherapy protocol with one of three modalities of CNS prophylaxis, depending on their treatment era. In addition to intrathecal therapy, CNS-directed therapy consisted of CRT (18 Gy in 10 fractions) in 25 patients, high-dose intravenous (IV) MTX (8 g/m2 x 3 doses) in 32 patients and very high-dose IV MTX (33.6 g/m2 x 3 doses) in 22 patients. Participants completed tests of intelligence, academic achievement, attention, and memory. Neurocognitive assessment was conducted at least 5 years after diagnosis (mean, 10.5 years, standard deviation, 2.7 years). No difference was detected on any neurocognitive measure between children treated with high-dose or very high-dose IV MTX. The combined MTX groups scored near the population mean on 17/18 measures. Children treated with CRT performed more poorly than the MTX group on most measures. Treatment strategies for young children with ALL that avoid CRT are associated with good long-term neurocognitive outcomes. In this cohort, the dose of IV MTX did not influence these outcomes.