Cognitive predictors of social adjustment in pediatric brain tumor survivors treated with photon versus proton radiation therapy

Neurocognitive outcomes and functional independence in adult survivors of childhood medulloblastoma diagnosed over 3 decades

BACKGROUND

Treatment of childhood medulloblastoma has evolved to reduce neurotoxicity while improving survival. However, the impact of evolving therapies on late neurocognitive outcomes and adult functional independence remains unknown.

METHODS

Adult survivors of childhood medulloblastoma (n = 505; median [minimum-maximum] age, 29 [18-46] years) and sibling controls (n = 727; 32 [18-58] years) from the Childhood Cancer Survivor Study completed surveys assessing neurocognitive problems and chronic health conditions (CHCs). Treatment exposures were categorized as historical (craniospinal irradiation [CSI] ≥ 30 Gy, no chemotherapy), standard-risk (CSI > 0 to <30 Gy + chemotherapy) and high-risk (CSI ≥ 30 Gy + chemotherapy) therapy. Latent class analysis identified patterns of functional independence using employment, independent living, assistance with routine/personal care needs, driver's license, and marital/partner status. Multivariable models estimated the risk of neurocognitive impairment in survivors versus siblings and by treatment exposure group, and associations between neurocognitive impairment, CHCs, and functional independence.

RESULTS

Survivors in each treatment exposure group had a 4- to 5-fold elevated risk of impaired memory and task efficiency compared to siblings. Contemporary risk-based therapies did not confer lower risk compared to historical therapy. Survivors treated in the 1990s had a higher risk of memory impairment (relative risk [RR] 2.24, 95% confidence interval 1.39-3.60) compared to survivors treated in the 1970s. Sensorimotor, hearing problems, and seizures were associated with 33-34%, 25-26%, and 21-42% elevated risk of task efficiency and memory impairment, respectively. Treatment-related CHCs and neurocognitive impairment were associated with nonindependence.

CONCLUSIONS

Despite treatment changes, long-term survivors of childhood medulloblastoma remain at risk for neurocognitive impairment, which was associated with CHCs. Neurocognitive surveillance after contemporary regimens is imperative.

Psychosocial and executive functioning late effects in pediatric brain tumor survivors after proton radiation

PURPOSE

Pediatric brain tumor survivors can experience detrimental effects from radiation treatment. This cross-sectional, large cohort study examined late psychosocial and executive functioning effects in pediatric patients treated ≥ 3 years after proton radiation therapy (PRT).

METHODS

Parents of 101 pediatric brain tumor survivors completed the Behavior Assessment System for Children and the Behavior Rating Inventory of Executive Function. Standard scores were compared to published normative means, rates of impairment (T-score > 65) were calculated, and demographic and clinical characteristics were examined.

RESULTS

Mean age at PRT was 8.12 years and mean interval from PRT to assessment was 6.05 years. Half were female (49.5%), 45.5% received craniospinal irradiation (CSI), and 58.4% were diagnosed with infratentorial tumors. All mean T-scores were within normal range. Mean T-scores were significantly elevated compared to the norm on the withdrawal, initiate, working memory, and plan/organize scales. Rates of impairment were notably high in working memory (24.8%), initiate (20.4%), withdrawal (18.1%), and plan/organize (17.0%). Greater withdrawal was significantly associated with CSI and also with chemotherapy and diagnosis of hearing loss. Mean T-scores were significantly lower than the norm on the hyperactivity, aggression, conduct problems, and inhibition scales. No significant problems were identified with social skills or depression. Interval since treatment was not correlated with any scale.

CONCLUSION

Although psychosocial and executive functioning was within the normal range, on average, social withdrawal and metacognitive executive functioning (working memory, initiating, planning/organizing) were areas of concern. Targeted yearly screening and proactive executive skill and social interventions are needed for this population.

Predicting neuropsychological late effects in pediatric brain tumor survivors using the Neurological Predictor Scale and the Pediatric Neuro-Oncology Rating of Treatment Intensity

OBJECTIVE

The Neurological Predictor Scale (NPS) quantifies cumulative exposure to tumor- and treatment-related neurological risks. The Pediatric Neuro-Oncology Rating of Treatment Intensity (PNORTI) measures the intensity of different treatment modalities, but research is needed to establish whether it is associated with late effects. This study evaluated the predictive validity of the NPS and PNORTI for neuropsychological outcomes in pediatric brain tumor survivors.

METHOD

A retrospective chart review was completed of pediatric brain tumor survivors (PBTS) (n = 161, Mage = 13.47, SD = 2.80) who were at least 2 years from the end of tumor-directed treatment. Attention, intellectual functioning, perceptual reasoning, processing speed, verbal reasoning, and working memory were analyzed in relation to the NPS and PNORTI.

RESULTS

NPS scores ranged from 1 to 11 (M = 5.57, SD = 2.27) and PNORTI scores ranged from 1 (n = 101; 62.7%) to 3 (n = 18; 11.2%). When controlling for age, sex, SES factors, and time since treatment, NPS scores significantly predicted intellectual functioning [F(7,149) = 12.86, p < .001, R2 = .38] and processing speed [F(7,84) = 5.28, p < .001, R2 = .31]. PNORTI scores did not significantly predict neuropsychological outcomes.

CONCLUSIONS

The findings suggest that the NPS has value in predicting IF and processing speed above-and-beyond demographic variables. The PNORTI was not associated with neuropsychological outcomes. Future research should consider establishing clinical cutoff scores for the NPS to help determine which survivors are most at risk for neuropsychological late effects and warrant additional assessment.

Cognitive Sparing in Proton versus Photon Radiotherapy for Pediatric Brain Tumor Is Associated with White Matter Integrity: An Exploratory Study

Radiotherapy for pediatric brain tumors is associated with reduced white matter structural integrity and neurocognitive decline. Superior cognitive outcomes have been reported following proton radiotherapy (PRT) compared to photon radiotherapy (XRT), presumably due to improved sparing of normal brain tissue. This exploratory study examined the relationship between white matter change and late cognitive effects in pediatric brain tumor survivors treated with XRT versus PRT. Pediatric brain tumor survivors treated with XRT (n = 10) or PRT (n = 12) underwent neuropsychological testing and diffusion weighted imaging >7 years post-radiotherapy. A healthy comparison group (n = 23) was also recruited. Participants completed age-appropriate measures of intellectual functioning, visual-motor integration, and motor coordination. Tractography was conducted using automated fiber quantification (AFQ). Fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD) were extracted from 12 tracts of interest. Overall, both white matter integrity (FA) and neuropsychological performance were lower in XRT patients while PRT patients were similar to healthy control participants with respect to both FA and cognitive functioning. These findings support improved long-term outcomes in PRT versus XRT. This exploratory study is the first to directly support for white matter integrity as a mechanism of cognitive sparing in PRT.

Superior verbal learning and memory in pediatric brain tumor survivors treated with proton versus photon radiotherapy

OBJECTIVE

Radiotherapy for pediatric brain tumor has been associated with late cognitive effects. Compared to conventional photon radiotherapy (XRT), proton radiotherapy (PRT) delivers lower doses of radiation to healthy brain tissue. PRT has been associated with improved long-term cognitive outcomes compared to XRT. However, there is limited research comparing the effects of XRT and PRT on verbal memory.

METHOD

Survivors of pediatric brain tumor treated with either XRT (n = 29) or PRT (n = 51) completed neuropsychological testing > 1 year following radiotherapy. Performance on neuropsychological measures was compared between treatment groups using analysis of covariance. Chi-squared tests of independence were used to compare the frequency of encoding, retrieval, and intact memory profiles between treatment groups. Associations between memory performance and other neurobehavioral measures were examined using Pearson correlation.

RESULTS

Overall, patients receiving PRT demonstrated superior verbal learning and recall compared to those treated with XRT. Encoding and retrieval deficits were more common in the XRT group than the PRT group, with encoding problems being most prevalent. The PRT group was more likely to engage in semantic clustering strategies, which predicted better encoding and retrieval. Encoding ability was associated with higher intellectual and adaptive functioning, and fewer parent-reported concerns about day-to-day attention and cognitive regulation.

CONCLUSION

Results suggest that PRT is associated with verbal memory sparing, driven by effective encoding and use of learning strategies. Future work may help to clarify underlying neural mechanisms associated with verbal memory decline, which will better inform treatment approaches. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Influences on cognitive outcomes in adult patients with gliomas: A systematic review

People with brain tumors, including those previously treated, are commonly affected by a range of neurocognitive impairments involving executive function, memory, attention, and social/emotional functioning. Several factors are postulated to underlie this relationship, but evidence relating to many of these factors is conflicting and does not fully explain the variation in cognitive outcomes seen in the literature and in clinical practice. To address this, we performed a systematic literature review to identify and describe the range of factors that can influence cognitive outcomes in adult patients with gliomas. A literature search was performed of Ovid MEDLINE, PsychINFO, and PsycTESTS from commencement until September 2021. Of 9,998 articles identified through the search strategy, and an additional 39 articles identified through other sources, 142 were included in our review. The results confirmed that multiple factors influence cognitive outcomes in patients with gliomas. The effects of tumor characteristics (including location) and treatments administered are some of the most studied variables but the evidence for these is conflicting, which may be the result of methodological and study population differences. Tumor location and laterality overall appear to influence cognitive outcomes, and detection of such an effect is contingent upon administration of appropriate cognitive tests. Surgery appears to have an overall initial deleterious effect on cognition with a recovery in most cases over several months. A large body of evidence supports the adverse effects of radiotherapy on cognition, but the role of chemotherapy is less clear. To contrast, baseline cognitive status appears to be a consistent factor that influences cognitive outcomes, with worse baseline cognition at diagnosis/pre-treatment correlated with worse long-term outcomes. Similarly, much evidence indicates that anti-epileptic drugs have a negative effect on cognition and genetics also appear to have a role. Evidence regarding the effect of age on cognitive outcomes in glioma patients is conflicting, and there is insufficient evidence for gender and fatigue. Cognitive reserve, brain reserve, socioeconomic status, and several other variables discussed in this review, and their influence on cognition and recovery, have not been well-studied in the context of gliomas and are areas for focus in future research.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42017072976.