Neuropsychological outcome after fractionated stereotactic radiotherapy (FSRT) for base of skull meningiomas: a prospective 1-year follow-up

The neural bases of the reach-grasp movement in humans: Quantitative evidence from brain lesions

Visually guided grasping is a fundamental building block of animal behavior, the specific neural mechanisms of which remain poorly documented in the human brain. We have mapped the causal contribution of different brain parts to grasping behavior by studying the kinematic parameters of 33 patients with brain tumors, engaged in actions directed toward objects of different sizes. Using motion capture techniques, we analyzed the dynamics of grip aperture and wrist transport. Voxel-based lesion-symptom mapping analysis was applied to correlate lesion volumes with specific behavioral deficits. Results showed that lesions in the anterior and lateral bank of the intraparietal sulcus produced impaired finger scaling related to object size. Conversely, impaired velocity of finger aperture was associated with lesions in the dorsal premotor cortex (PMd). Grip aperture deficits following dominant hemisphere lesions were bilateral and were unilateral when following nondominant hemisphere lesions. Impaired wrist transport during reaching was associated with lesions in the first segment of the superior longitudinal fasciculus. Our work highlights an architecture of the grasping network in humans, with unique species-specific features. We hypothesize a model of human neural architecture in which object geometry for hand preshaping is first coded in the left anterior intraparietal cortex and then shared with the right hemisphere. Execution of the motor program of hand preshaping is then performed by the PMd on the corresponding side.

Oncology: Brain asymmetries in language-relevant brain tumors

Brain tumors are classified as rare diseases, with an annual occurrence of 300,000 cases and account for an annual loss of 241,000 lives, highlighting their devastating nature. Recent advancements in diagnosis and treatment have significantly improved the management and care of brain tumors. This chapter provides an overview of the common types of primary brain tumors affecting language functions-gliomas and meningiomas. Techniques for identifying and mapping critical language areas, including the white matter language system, such as awake brain tumor surgery and diffusion-weighted tractography, are pivotal for understanding language localization and informing personalized treatment approaches. Numerous studies have demonstrated that gliomas in the dominant hemisphere can lead to (often subtle) impairments across various cognitive domains, with a particular emphasis on language. Recently, increased attention has been directed toward (nonverbal) cognitive deficits in patients with gliomas in the nondominant hemisphere, as well as cognitive outcomes in patients with meningiomas, a group historically overlooked. A patient-tailored approach to language and cognitive functions across the pre-, intra-, and postoperative phases is mandatory for brain tumor patients to preserve quality of life. Continued follow-up studies, in conjunction with advanced imaging techniques, are crucial for understanding the brain's potential for neuroplasticity and optimizing patient outcomes.

Evaluation of Factors Influencing Postoperative Cognitive Dysfunction in Patients After Cranial Tumor Surgery

BACKGROUND

The authors retrospectively analyzed the perioperative data of 81 patients who underwent cranial tumor surgery to explore the factors influencing POCD in patients after the surgery.

METHODS

The authors evaluated preoperative cognitive dysfunction using the Mini-Mental State Examination (MMSE) score measured. For patients whose cognitive function was normal, the authors retrieved the MMSE score on the seventh day after surgery and compared it to determine whether the patients had POCD. The authors used a univariate logistic regression analysis to analyze the perioperative factors in patients, namely, age, gender, history of underlying diseases, tumor size, peritumoral edema, duration of surgery, blood loss, intraoperative fluid infusion, and type of anesthetic drugs. The authors then performed a multivariate logistic regression analysis for the statistically significant factors.

RESULTS

The authors found that 23 of 81 patients (28.4%) developed POCD. Univariate logistic analysis showed that a history of diabetes mellitus, peritumoral edema, intraoperative blood loss, and anesthetic drugs were the risk factors for patients developing POCD after cranial tumor surgery. Multivariate logistic regression analysis showed that a history of diabetes mellitus, peritumoral edema, and use of ciprofol as the anesthetic drug were independent risk factors for POCD after cranial tumor surgery.

CONCLUSIONS

A history of diabetes mellitus, the degree of brain tumor edema, and the choice of anesthetic drugs significantly influence the occurrence of POCD in patients after cranial tumor surgery.

[Prospective longitudinal study on the evolution of autobiographical memory in patients irradiated for benign skull base tumour]

PURPOSE

Cranial irradiation can lead to long-term neurological complications, in particular memory disorders. The aim of this prospective study is to evaluate the impact of irradiation of benign skull base tumours located near the hippocampi on autobiographical memory.

PATIENTS AND METHODS

From 2016 to 2019, patients with cavernous sinus meningioma or pituitary adenoma treated with normofractionated irradiation were included. Patients underwent full neuropsychological assessment at baseline, 1year and 2years post-treatment. Neuropsychological tests were converted to Z-Score for comparability.

RESULTS

Twelve of the 19 patients included had a complete neuropsychological evaluation at 2years and were analysed. On the "TEMPau" test, no significant difference in autobiographical memory was found at 2years, regardless of the period of autobiographical memory. The mean hippocampal dose had no impact on the variation in autobiographical memory. There was no significant cognitive impairment in the other domains assessed, such as attention, anterograde memory, working memory and executive functions. Autobiographical memory was independent of these other cognitive domains, which justifies its specific study.

CONCLUSION

Radiotherapy to the skull base for a benign pathology does not lead to significant cognitive impairment. Longer follow-up would be needed to confirm these results.

Health-Related Quality of Life Outcomes in Meningioma Patients Based upon Tumor Location and Treatment Modality: A Systematic Review and Meta-Analysis

Patients with meningiomas may have reduced health-related quality of life (HRQoL) due to postoperative neurological deficits, cognitive dysfunction, and psychosocial burden. Although advances in surgery and radiotherapy have improved progression-free survival rates, there is limited evidence regarding treatment outcomes on HRQoL. This review examines HRQoL outcomes based on tumor location and treatment modality. A systematic search in PubMed yielded 28 studies with 3167 patients. The mean age was 54.27 years and most patients were female (70.8%). Approximately 78% of meningiomas were located in the skull base (10.8% anterior, 23.3% middle, and 39.7% posterior fossae). Treatment modalities included craniotomy (73.6%), radiotherapy (11.4%), and endoscopic endonasal approach (EEA) (4.0%). The Karnofsky Performance Scale (KPS) was the most commonly utilized HRQoL instrument (27%). Preoperative KPS scores > 80 were associated with increased occurrence of postoperative neurological deficits. A significant difference was found between pre- and post-operative KPS scores for anterior/middle skull base meningiomas (SBMs) in comparison to posterior (SBMs) when treated with craniotomy. Post-craniotomy SF-36 scores were lower for posterior SBMs in comparison to those in the anterior and middle fossae. Risk factors for poor neurological outcomes include a high preoperative KPS score and patients with posterior SBMs may experience a greater burden in HRQoL.

Preservation of Neurocognition after Proton Beam Radiation Therapy for Intracranial Tumors: First Results from REGI-MA-002015

PURPOSE

Proton beam radiation therapy reduces dose to healthy brain tissue and thereby decreases the risk of treatment-related decline in neurocognition. Considering the paucity of prospective data, this study aimed to evaluate neurocognitive performance in an adult patient population with intracranial tumors.

METHODS AND MATERIALS

Between 2017 and 2021, patients enrolled in the MedAustron registry study and irradiated for intracranial tumors were eligible for neurocognitive assessment. Patients with available 1-year follow-up data were included in the analysis. The test battery consisted of a variety of standardized tests commonly used in European Organization for Research and Treatment of Cancer trials. Scores were transformed into z scores to account for demographic effects, and clinically relevant change was defined as a change of ≥1.5 standard deviations. Binary logistic regression analysis and the χ² test were conducted for clinical parameters and dosimetric hippocampal parameters to evaluate the relationship with overall cognitive decline and changes in memory.

RESULTS

One hundred twenty-three patients with mostly nonprogressive, extra-axial tumors and neurocognitive assessment at baseline and treatment end as well as 3, 6, and 12 months after completion of proton beam radiation therapy were analyzed. Overall, 7 test scores revealed stability in neurocognitive function with minimal positive changes 1 year after treatment completion (statistically significant in 6 of 7 tests), whereas the majority had no or minimal baseline deficits. At 1-year follow-up, 89.4% of all patients remained stable in their overall cognitive functioning without clinically relevant deterioration in 2 or more tests. None of them showed disease progression. Of the patients, 8.1% presented with radiation-induced brain lesions and exhibited a higher percentage of overall cognitive deterioration without reaching statistical significance. Multivariate binary logistic regression analysis revealed higher age at baseline as the only independent parameter to be associated with an overall clinically relevant cognitive decline. There was no significant correlation of hippocampal doses and memory functioning.

CONCLUSIONS

One year after proton therapy, we observed preservation of cognitive functioning in the vast majority of our patients with intracranial tumors.

Neurocognitive Performance in Adults Treated With Radiation for a Primary Brain Tumor

PURPOSE

The contributory effects of radiation dose to different brain regions on neurocognitive performance after radiation therapy (RT) for primary brain tumors is not well known.

METHODS AND MATERIALS

In this retrospective cohort study, 30 patients with brain tumors treated with photon RT were identified, and radiation dosimetric parameters across brain regions were calculated. All patients had longitudinal neurocognitive evaluations at baseline and after treatment. Generalized estimating equations were used to model each neurocognitive endpoint over time in a multivariable analysis, while adjusted for multiple comparisons of brain regions.

RESULTS

Median follow-up from RT to last assessment was 4.1 years. Fewer years of formal education and older age at the time of RT were associated with lower scores in language, verbal memory, and working memory, after adjustment for baseline scores in multivariable analyses. Higher radiation dose to specific brain regions was not associated with declines in any of the evaluated cognitive domains. On average, there was no clinically significant decline (magnitude of z score change >1) between first and last neurocognitive evaluation. Across each individual cognitive domain, fewer than 15% of patients were impaired at most recent follow-up.

CONCLUSIONS

In this small study of 30 patients treated with RT for a primary brain tumor, brain region dosimetry was not associated with decline in cognitive performance. Older age at time of RT and fewer years of formal education were associated with declines in cognitive performance, suggesting that effects of nondosimetric factors on cognitive performance should be considered alongside treatment factors and dosimetry in neuro-oncology research.

Radiation dose to circumscribed brain regions and neurocognitive function in patients with meningioma

Background

Although radiation (RT) is standard treatment for many brain tumors, it may contribute to neurocognitive decline. The objective of this study was to investigate associations between RT dose to circumscribed brain regions and specific neurocognitive domains in patients with meningioma.

Methods

We undertook a retrospective study of 40 patients with meningioma who received RT and underwent an in-depth clinical neurocognitive assessment. Radiation dosimetry characteristics were delineated based on treatment planning computerized tomography co-registered with contrast-enhanced 3D T1-weighted magnetic resonance imaging. Principal components analysis was applied to organize neurocognitive test scores into factors, and multivariate multiple linear regression models were undertaken to examine if RT dose to circumscribed brain regions is associated with specific neurocognitive outcomes.

Results

Radiation dose to brain regions was associated with neurocognitive functions across a number of domains. High dose to the parietal-occipital region was associated with slower visuomotor processing speed (mean dose, β = -1.100, P = .017; dose to 50% of the region [D50], β = -0.697, P = .049). In contrast, high dose to the dorsal frontal region was associated with faster visuomotor processing speed (mean dose, β = 0.001, P = .036).

Conclusions

These findings suggest that RT delivered to brain regions (ie, parietal-occipital areas) may contribute to poor neurocognitive outcomes. Given that modern radiotherapy techniques allow for precise targeting of dose delivered to brain regions, prospective trials examining relations between dose and neurocognitive functions are warranted to confirm these preliminary results.

Cognitive and psychosocial outcomes following stereotactic radiosurgery for acoustic neuroma

BACKGROUND

Acoustic Neuroma (AN) is a benign tumour of the eighth cranial nerve. Stereotactic Radiosurgery (SRS) is a common treatment approach. Studies have explored the primary effects of SRS and documented equivalent efficacy for tumour control compared to neurosurgery.

OBJECTIVE

Examine the longer term cognitive and psychosocial outcomes of SRS in non-Neurofibromatosis Type II patients utilising both objective and subjective cognitive outcomes associated with quality of life and health related distress.

METHODS

Nineteen individuals treated via SRS were assessed using a battery of standardised psychometric tests as well as measures of quality of life and psychological distress.

RESULTS

Participants had largely preserved cognitive function except for processing speed, aspects of attention and visual memory relative to age norms. Self-reported quality of life was better than in other AN population studies. Level of psychological distress was equivalent to general population norms. More than half of participants reported subjective cognitive decline though this was not fully supported by objective testing. Subjective cognitive complaints may be associated with lower reported quality of life.

CONCLUSIONS

Results are largely consistent with previous findings on the effects of SRS in other clinical groups, which supports SRS as a targeted radiation treatment for AN.

Cognitive and affective theory of mind double dissociation after parietal and temporal lobe tumours

Extensive neuroimaging literature suggests that understanding others' thoughts and emotions engages a wide network encompassing parietal, temporal and medial frontal brain areas. However, the causal role played by these regions in social inferential abilities is still unclear. Moreover very little is known about ToM deficits in brain tumours and whether potential anatomical substrates are comparable to those identified in fMRI literature. This study evaluated the performance of 105 tumour patients, before and immediately after brain surgery, on a cartoon-based non-verbal task evaluating Cognitive (Intention Attribution) and Affective (Emotion Attribution) ToM, as well as a non-social control condition (Causal Inference). Across multiple analyses, we found converging evidence of a double dissociation between patients with right superior parietal damage, selectively impaired in Intention Attribution, and those with right antero-medial temporal lesion, exhibiting deficits only in Emotion attribution. Instead, patients with damage to the frontal cortex were impaired in all kinds of inferential processes, including those from the non-social control conditions. Overall, our data provides novel reliable causal evidence of segregation between different aspects of the ToM network from both the cognitive and also the anatomical point of view.

EANO guideline on the diagnosis and management of meningiomas

Meningiomas are the most common intracranial tumors. Yet, only few controlled clinical trials have been conducted to guide clinical decision making, resulting in variations of management approaches across countries and centers. However, recent advances in molecular genetics and clinical trial results help to refine the diagnostic and therapeutic approach to meningioma. Accordingly, the European Association of Neuro-Oncology (EANO) updated its recommendations for the diagnosis and treatment of meningiomas. A provisional diagnosis of meningioma is typically made by neuroimaging, mostly magnetic resonance imaging. Such provisional diagnoses may be made incidentally. Accordingly, a significant proportion of meningiomas, notably in patients that are asymptomatic or elderly or both, may be managed by a watch-and-scan strategy. A surgical intervention with tissue, commonly with the goal of gross total resection, is required for the definitive diagnosis according to the WHO classification. A role for molecular profiling including gene panel sequencing and genomic methylation profiling is emerging. A gross total surgical resection including the involved dura is often curative. Inoperable or recurrent tumors requiring treatment can be treated with radiosurgery, if the size or the vicinity of critical structures allows that, or with fractionated radiotherapy (RT). Treatment concepts combining surgery and radiosurgery or fractionated RT are increasingly used, although there remain controversies regard timing, type, and dosing of the various RT approaches. Radionuclide therapy targeting somatostatin receptors is an experimental approach, as are all approaches of systemic pharmacotherapy. The best albeit modest results with pharmacotherapy have been obtained with bevacizumab or multikinase inhibitors targeting vascular endothelial growth factor receptor, but no standard of care systemic treatment has been yet defined.

Neuropsychological Outcomes after Surgery for Olfactory Groove Meningiomas

BACKGROUND

In recent years, several studies have reported abnormal pre- and postoperative neuropsychological functioning in patients with meningiomas located in the prefrontal cortex (notably the ventromedial region). In the case of olfactory groove meningiomas, the tumor is in direct contact with the inferior aspect of the prefrontal cortex, a cortical region with crucial roles in decision-making, cognition and memory functions, potentially negatively impacting neuropsychological functions.

MATERIALS AND METHODS

We retrospectively compared pre- and post-operative neuropsychological testing of 17 patients undergoing surgical removal of olfactory groove meningiomas in our institution between January 2013 and December 2018. Neuropsychological results were obtained from the patients' medical history and normalized as z-scores of their respective cognitive functions.

RESULTS

Assessment of cognitive follow-up showed an important heterogeneity among patients. Pre-operative cognitive impairment was observed in most patients, particularly in cognitive flexibility (mean z-score: -1.35). Immediate post-operative cognitive status showed an overall impairment in all domains of cognition, significant for the domains of attention (p = 0.0273) and flexibility (p = 0.0234) and almost significant for the domain of language (p = 0.0547). The late follow-up at one year showed a trend towards general improvement, although attention and flexibility remained impaired.

DISCUSSION

Olfactory groove meningiomas impact pre-frontal cortex cognitive functions, particularly in the domain of cognitive flexibility. After an initial postoperative worsening, patients tended to improve in most aspects after one year, aside from cognitive flexibility and attention.

Postoperative cognitive functions in patients with benign intracranial lesions

The aim of this study was to assess pre- and postoperative cognitive functions in patients who underwent surgery for benign intracranial lesions. In total, 58 patients (21 men, 37 women, mean age 51.6 years [range 24–76 years]) with benign intracranial lesions (including benign tumors and vascular lesions) and neuralgia of the trigeminal nerve were included in this prospective study. Extensive cognitive testing was used to categorize attention, memory, and executive functions. Mood and pain were assessed preoperatively (t₀, mean 3.7 days before surgery), immediately after surgery/during inpatient stay (t₁, mean 7.6 days after surgery), and at first outpatient check-up (t₂, mean 99.5 days after surgery). All 58 patients were tested at t₀ and t₁, but at t₂ only 24 patients were available at t₂. The data were categorized as improvement/stable condition or deterioration and shown as percentages. The pre- and postoperative values of BDI-II and mood were compared by the Wilcoxon test for paired samples. Binary logistic regression analyses were performed to identify parameters influencing cognition in the subgroup of meningioma patients. Immediately after surgery (t₁), the percentage of patients with improvement/stable condition was > 50% in all categories in the majority of subtests (attention: 12/14 subtests, memory: 11/13 subtests, executive functions: 6/9 subtests). Similar results were shown at t₂. Mood and pain did not change significantly after surgery. Factors like age, Karnofsky performance status, and tumor volume were not shown as significant influencing factors for cognitive functions in meningioma patients. The results of this study suggest that—in contrast to neuroepithelial tumors—cognitive functions do not deteriorate after surgery of benign intracranial lesions. Further studies are necessary to evaluate the results of this study.

Meningiomas and Cognitive Impairment after Treatment: A Systematic and Narrative Review

Simple Summary

Assessment of cognition is crucial in brain tumor care, and clinical outcome along this axis is frequently neglected. As a result, a patient’s quality of life seems more impacted than usually reported in clinical series. With this article, we review the current state of affairs and search for patient- and meningioma-related outcome predictors. We found a great variety in the number and types of neuropsychological tests used and in the dimensions of cognition studied. Furthermore, data mostly originate from a selected part of the globe and therefore may not reflect a global reality. Treatment has an early cognitive impact in the majority of meningioma patients. Further long-term conclusions are precluded by a mean follow-up time shorter than one year. Anticipating cognition outcomes prior to, during, and after treatment of meningiomas remains difficult. Future research should aim for a reliable and worldwide reproducible standard battery of tests.

Abstract

Clinical outcomes after surgery for intracranial meningiomas might be overvalued as cognitive dimensions and quality of life are probably underreported. This review aims to summarize the current state of cognitive screening and treatment-related outcomes after meningioma surgery. We present a systematic review (Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA-P) 2015-based) of cognitive outcomes after intracranial meningioma surgery. A total of 1572 patients (range 9–261) with a mean age of 58.4 years (range 23–87), and predominantly female (n = 1084, 68.9%) were identified. Mean follow-up time after treatment was 0.86 ± 0.3 years. Neuropsychological assessment was very heterogeneous, but five dimensions of cognition were described: memory (19/22); attention (18/22); executive functions (17/22); language (11/22); flexibility (11/22 studies). Cognitive abilities were impaired in 18 studies (81.8%), but only 1 showed deterioration in all dimensions simultaneously. Memory was the most affected. with significant post-therapy impairment in 9 studies (40.9%). Postoperatively, only 4 studies (18.2%) showed improvement in at least one dimension. Meningioma patients had significantly lower cognitive scores when compared to healthy subjects. Surgery and radiotherapy for meningiomas were associated with cognitive impairment, probably followed by a partial recovery. Cognition is poorly defined, and the assessment tools employed lack standardization. Cognitive impairment is probably underreported in meningioma patients.

Cognitive reserve protects language functions in patients with brain tumours

Cognitive reserve (CR) theory suggests that individual differences in general intelligence (IQ), occupational attainment or participation in leisure/recreational activities protect against cognitive decline. However the relationship between CR and cognitive functioning in patients with brain tumours has been very rarely investigated in past research. The present study systematically assesses whether CR concept can also be applied to cognitive functions of neurosurgical patients affected by brain tumours. We investigated the role of different CR proxies (education level, premorbid IQ, current IQ, working and leisure activity) in protecting language against brain tumours and surgery effects, considering interactions with demographic (sex/age), anatomical (hemisphere/lobe location of lesion) and clinical/biological variables (tumour type: High/Low Grade Glioma or Meningioma; lesion volume; lesion aggressiveness). One-hundred patients undergoing neuropsychological assessment before and immediately after surgery participated. A "Language Score" summarizing performance on all language tests was derived with Principal Component Analysis. Data were then analyzed with Multiple Regression and Classification and Regression Tree analyses to investigate possible relationships between predictors (CR proxies and clinical variables) and Language Score. We found that premorbid IQ was the best predictor of pre-operatory language integrity, above and beyond all clinical variables considered, also moderating lesion volume effects. Moreover, patients with lower pre-operatory language integrity and low-to-moderately aggressive tumours showed a mitigating effect of current IQ over surgery consequences. Results thus suggest that different CR proxies play a role in moderating cognitive decline following brain tumours and surgery.

Image-Guided Multisession Radiosurgery of Skull Base Meningiomas

Simple Summary

Stereotactic radiosurgery has changed the landscape of treatment for skull base meningiomas. Lesions encasing or compressing radiosensitive structures are considered not suitable for single session stereotactic radiosurgery because of the high risk of side effects. Multisession stereotactic radiosurgery can reduce these risks, allowing for normal tissue repair between fractions, while delivering a high dose per fraction. The aim of this study is to validate the role of multi-session stereotactic radiosurgery in the treatment of skull base meningiomas, through a retrospective analysis of 156 patients affected by skull base meningioma, treated at the University of Messina between 2008 and 2018. Our study suggests that multisession stereotactic radiosurgery represents a safe and effective profile in the treatment of skull base meningioma, providing a satisfactory local control and a low toxicity rate, together with patient comfort from a frameless procedure.

Abstract

Background: The efficacy of single-session stereotactic radiosurgery (sSRS) for the treatment of intracranial meningioma is widely recognized. However, sSRS is not always feasible in cases of large tumors and those lying close to critically radiation-sensitive structures. When surgery is not recommended, multi-session stereotactic radiosurgery (mSRS) can be applied. Even so, the efficacy and best treatment schedule of mSRS are not yet established. The aim of this study is to validate the role of mSRS in the treatment of skull base meningiomas. Methods: A retrospective analysis of patients with skull base meningiomas treated with mSRS (two to five fractions) at the University of Messina, Italy, from 2008 to 2018, was conducted. Results: 156 patients met the inclusion criteria. The median follow-up period was 36.2 ± 29.3 months. Progression-free survival at 2-, 5-, and 10- years was 95%, 90%, and 80.8%, respectively. There were no new visual or motor deficits, nor cranial nerves impairments, excluding trigeminal neuralgia, which was reported by 5.7% of patients. One patient reported carotid occlusion and one developed brain edema. Conclusion: Multisession radiosurgery is an effective approach for skull base meningiomas. The long-term control is comparable to that obtained with conventionally-fractionated radiotherapy, while the toxicity rate is very limited.

Whole-brain irradiation differentially modifies neurotransmitters levels and receptors in the hypothalamus and the prefrontal cortex

BACKGROUND

Whole-brain radiotherapy is a primary treatment for brain tumors and brain metastasis, but it also induces long-term undesired effects. Since cognitive impairment can occur, research on the etiology of secondary effects has focused on the hippocampus. Often overlooked, the hypothalamus controls critical homeostatic functions, some of which are also susceptible after whole-brain radiotherapy. Therefore, using whole-brain irradiation (WBI) in a rat model, we measured neurotransmitters and receptors in the hypothalamus. The prefrontal cortex and brainstem were also analyzed since they are highly connected to the hypothalamus and its regulatory processes.

METHODS

Male Wistar rats were exposed to WBI with 11 Gy (Biologically Effective Dose = 72 Gy). After 1 month, we evaluated changes in gamma-aminobutyric acid (GABA), glycine, taurine, aspartate, glutamate, and glutamine in the hypothalamus, prefrontal cortex, and brainstem according to an HPLC method. Ratios of Glutamate/GABA and Glutamine/Glutamate were calculated. Through Western Blott analysis, we measured the expression of GABAa and GABAb receptors, and NR1 and NR2A subunits of NMDA receptors. Changes were analyzed comparing results with sham controls using the non-parametric Mann-Whitney U test (p < 0.05).

RESULTS

WBI with 11 Gy induced significantly lower levels of GABA, glycine, taurine, aspartate, and GABAa receptor in the hypothalamus. Also, in the hypothalamus, a higher Glutamate/GABA ratio was found after irradiation. In the prefrontal cortex, WBI induced significant increases of glutamine and glutamate, Glutamine/Glutamate ratio, and increased expression of both GABAa receptor and NMDA receptor NR1 subunit. The brainstem showed no statistically significant changes after irradiation.

CONCLUSION

Our findings confirm that WBI can affect rat brain regions differently and opens new avenues for study. After 1 month, WBI decreases inhibitory neurotransmitters and receptors in the hypothalamus and, conversely, increases excitatory neurotransmitters and receptors in the prefrontal cortex. Increments in Glutamate/GABA in the hypothalamus and Glutamine/Glutamate in the frontal cortex indicate a neurochemical imbalance. Found changes could be related to several reported radiotherapy secondary effects, suggesting new prospects for therapeutic targets.

Predictors of pre-operative cognitive impairment in meningioma patients over 60 years old

BACKGROUND

The aim of this study was to assess the cognitive function of patients over 60 years old with meningioma using a domain-specific neuropsychological test and to investigate the relevant factors affecting pre-operative cognitive decline in different subdomains.

METHODS

We retrospectively investigated 46 intracranial meningioma patients between the ages of 60 and 85 years. All patients underwent brain MRI and neuropsychological test. Tumor size, location, peritumoral edema, and medial temporal atrophy (MTA) were examined to determine the association with cognitive impairment. We performed a logistic regression analysis to examine the odds ratios (ORs) for cognitive decline of four subdomains: verbal memory, language, visuospatial, and executive functions.

RESULTS

Tumor size and age were associated with executive dysfunction (OR 1.083, 95% confidence interval (CI) 1.006-1.166, and OR 1.209, 95% CI 1.018-1.436, respectively). There was no statistically significant association in other cognitive domains (language, verbal memory, and visuospatial function) with variables in regression analysis.

CONCLUSIONS

We conclude that tumor size and age are positively related with executive function in pre-operative meningioma patients over 60 years old.

External beam radiation therapy for meningioma

Radiation therapy (RT) plays an important role in the management of meningioma. Surgery often remains the initial treatment of choice as it reduces mass effect and confirms the diagnosis and grade. However, RT has frequently been successful in the primary setting and is commonly employed as adjuvant therapy for incompletely resected tumors as well as for high-grade meningiomas regardless of resection extent. Some meningiomas develop in locations less amenable to resection or in patients who are poor surgical candidates, in which circumstances RT is particularly appropriate as primary treatment. Recent cooperative group studies including RTOG 0539 have better established the role of RT for meningioma. These studies suggest a role for adjuvant RT for completely resected Grade II meningioma, which was less clear historically. Ongoing clinical trials such as NRG BN 003 and ROAM will further clarify this. This chapter reviews the role of fractionated external beam RT for various grades of meningioma.

Normofractionated stereotactic radiotherapy versus CyberKnife-based hypofractionation in skull base meningioma: a German and Italian pooled cohort analysis

Background

This retrospective German and Italian multicenter analysis aimed to compare the role of normofractionated stereotactic radiotherapy (nFSRT) to CyberKnife-based hypofractionated stereotactic radiotherapy (CK-hFSRT) for skull base meningiomas.

Methods

Overall, 341 patients across three centers were treated with either nFSRT or CK-hFSRT for skull base meningioma. Treatment planning was based on computed tomography (CT) and magnetic resonance imaging (MRI) following institutional guidelines. Most nFSRT patients received 33 × 1.8 Gy, and most CK-hFSRT patients received 5 × 5 Gy. The median follow-up time was 36 months (range: 1–232 months).

Results

In the CK-hFSRT group, the 1-, 3-, and 10-year local control (LC) rates were 99.4, 96.8, and 80.3%, respectively. In the nFSRT group, the 1-, 3-, and 10-year LC rates were 100, 99, and 79.1%, respectively. There were no significant differences in LC rates between the nFSRT and CK-hFSRT groups (p = 0.56, hazard ratio = 0.76, 95% confidence interval, 0.3–1.9). In the CK-hFSRT group, only one case (0.49%) of severe toxicity (CTCAE 4.0 ≥ 3) was observed. In the nFSRT group, three cases (2.1%) of grade III toxicity were observed.

Conclusion

This analysis of pooled data from three centers showed excellent LC and low side effect rates for patients treated with CK-hFSRT or nFSRT. The efficacy, safety, and convenience of a shortened treatment period provide a compelling case for the use of CK-hFSRT in patients with moderate size skull base meningioma and provided that OAR constraints are met.

Risk factors for neurocognitive impairment in patients with benign intracranial lesions

This study was designed to assess risk factors for neurocognitive impairment in patients with benign intracranial lesions including tumors and vascular lesions. 74 patients (29 m, 51 f, mean age 54.4 years) with surgery for benign intracranial lesions were included in this prospective single-center study. Extensive neuropsychological testing was performed preoperatively, including tests for attention, memory and executive functions. Furthermore, headache and depression were assessed using the german version of the HDI (IBK) and the BDI-II. Multiple linear regression analyses of the percentile ranks (adjusted for age, sex and education) including the parameters age, Karnofsky Performance Status Scale (KPS), mood, pain and lesion size were performed to identify risk factors for cognitive impairment. Using the Mann-Whitney U test, the influence of hemisphere and type of lesion (tumor/vascular) was assessed. Posthoc Bonferroni correction was performed. Poorer neurocognitive functions were observed only in the category attention in patients with higher age (divided attention, WMS) and reduced KPS (WMS). Lesion volume, mood, pain, hemisphere or the type of the lesion (tumor, vascular) were not identified as risk factors for poorer neurocognitive functions in patients with benign intracranial lesions. Age and KPS are the main risk factors for poorer neurocognitive functions in the category attention in patients with benign intracranial lesions. Knowledge of these risk factors might be important to find appropriate therapy regimes to improve cognitive functions and quality of life.

The association between preoperative edema and postoperative cognitive functioning and health-related quality of life in WHO grade I meningioma patients

BACKGROUND

Studies on the associations between preoperative cerebral edema, cognitive functioning, and health-related quality of life (HRQOL) in WHO grade I meningioma patients are virtually lacking. We studied the association between preoperative cerebral edema on postoperative cognitive functioning and HRQOL 6 months postoperatively in WHO grade I meningioma patients.

METHODS

Twenty-one consecutive WHO grade I meningioma patients, who underwent surgery, were matched individually for age, gender, and educational level to healthy controls. Tumor and edema volume were assessed on preoperative T1- and T2-weighted MRI images, respectively. At least 5 months postoperatively, functional status, cognitive functioning, and HRQOL, using a cognitive test battery and the Short-Form Health Survey (SF-36), were determined. The correlation between preoperative tumor and cerebral edema volume with postoperative cognitive functioning and HRQOL was investigated using Kendall's tau coefficients.

RESULTS

Compared to healthy controls, patients had lower verbal memory capacity (p = .012), whereas HRQOL was similar to matched healthy controls. In all cognitive domains, postoperative functioning was much lower in patients with preoperative cerebral edema than in those without. There were significant correlations between preoperative cerebral edema and tumor volume and postoperative cognitive functioning. Preoperative cerebral edema and/or tumor volume were not associated with HRQOL.

CONCLUSIONS

Our results suggest that WHO grade I meningioma patients with larger volumes of preoperative cerebral edema are more at risk of experiencing limitations in longer-term cognitive functioning than patients with no or less edema preoperatively. This is an important knowledge for neurologists and neurosurgeons treating patients with a meningioma. More studies regarding the effect of peritumoral edema on cognitive functioning in meningioma patients are necessary.

Neurocognition in individuals with incidentally-identified meningioma

Meningiomas are primary intracranial tumors that are often asymptomatic. To our knowledge, no study has attempted to describe neurocognitive function in patients with incidentally-discovered meningioma. We utilized the Mayo Clinic Study of Aging (MCSA), which is a population-based sample of Olmsted County, Minnesota residents that includes neuropsychological testing and brain MRI approximately every 15 months. Using a text search of radiologists' notes of 2402 MCSA individuals (mean age 77 years, scanned between 2004 and 2014) we identified 48 eligible subjects (2%) who had at least one meningioma. Most meningiomas were small (90% <3 cm). We matched each of the 48 subjects to 5 non-demented MCSA controls (n = 240) on age, sex, and education. Cognitive domains assessed included memory, attention-executive function, language, and visuospatial. More women (67%) had a meningioma than men (33%). Groups did not differ on prevalence of Mild Cognitive Impairment (Meningioma = 19%, Controls = 13%). Across cognitive domains, we observed similar performance for the two groups (p's ≥ 0.21). Subtle differences emerged in memory and language domains (p = 0.05 and p = 0.11) when we divided the Meningioma group by tumor location, wherein the small group with an infratentorial tumor performed more poorly than controls globally as well as on select memory and language measures. Our findings suggest that small meningiomas are generally cognitively benign, but that may change as the tumor evolves, and might be impacted by other factors such as meningioma location.

Prospective analysis of neuropsychological deficits following resection of benign skull base meningiomas

OBJECTIVE Resection of skull base tumors is challenging. The introduction of alternative treatment options, such as radiotherapy, has sparked discussion regarding outcome in terms of quality of life and neuropsychological deficits. So far, however, no prospective data are available on this topic. METHODS A total of 58 patients with skull base meningiomas who underwent surgery for the first time were enrolled in this prospective single-center trial. The average age of the patients was 56.4 ± 12.5 years. Seventy-nine percent of the tumors were located within the anterior skull base. Neurological examinations and neuropsychological testing were performed at 3 time points: 1 day prior to surgery (T1), 3-5 months after surgery (T2), and 9-12 months after surgery (T3). The average follow-up duration was 13.8 months. Neuropsychological assessment consisted of quality of life, depression and anxiety, verbal learning and memory, cognitive speed, attention and concentration, figural memory, and visual-motor speed. RESULTS Following surgery, 23% of patients showed transient neurological deficits and 12% showed permanent new neurological deficits with varying grades of manifestation. Postoperative quality of life, however, remained stable and was slightly improved at follow-up examinations at T3 (60.6 ± 21.5 vs 63.6 ± 24.1 points), and there was no observed effect on anxiety and depression. Long-term verbal memory, working memory, and executive functioning were slightly affected within the first months following surgery and appeared to be the most vulnerable to impairment by the tumor or the resection but were stable or improved in the majority of patients at long-term follow-up examinations after 1 year. CONCLUSIONS This report describes the first prospective study of neuropsychological outcomes following resection of skull base meningiomas and, as such, contributes to a better understanding of postoperative impairment in these patients. Despite deterioration in a minority of patients on subscales of the measures used, the majority demonstrated stable or improved outcome at follow-up assessments.

Cognitive functioning in meningioma patients: a systematic review

This systematic review evaluates relevant findings and methodologic aspects of studies on cognitive functioning in meningioma patients prior to and/or following surgery with or without adjuvant radiotherapy. PubMed and Web of Science electronic databases were searched until December 2015. From 1012 initially identified articles, 11 met the inclusion criteria for this review. Multiple methodological limitations were identified which include the lack of pre-treatment assessments, variations in the number and types of neuropsychological tests used, the normative data used to identify patients with cognitive deficits, and the variety of definitions for cognitive impairment. Study results suggest that most of meningioma patients are faced with cognitive deficits in several cognitive domains prior to surgery. Following surgery, most of these patients seem to improve in cognitive functioning. However, they still have impairments in a wide range of cognitive functions compared to healthy controls. Suggestions are given for future research. Adequate diagnosis and treatment of cognitive deficits may ultimately lead to improved outcome and quality of life in meningioma patients.

Speed-accuracy strategy regulations in prefrontal tumor patients

The ability to flexibly switch between fast and accurate decisions is crucial in everyday life. Recent neuroimaging evidence suggested that left lateral prefrontal cortex plays a role in switching from a quick response strategy to an accurate one. However, the causal role of the left prefrontal cortex in this particular, non-verbal, strategy switch has never been demonstrated. To fill this gap, we administered a perceptual decision-making task to neuro-oncological prefrontal patients, in which the requirement to be quick or accurate changed randomly on a trial-by-trial basis. To directly assess hemispheric asymmetries in speed-accuracy regulation, patients were tested a few days before and a few days after surgical excision of a brain tumor involving either the left (N=13) or the right (N=12) lateral frontal brain region. A group of age- and education-matched healthy controls was also recruited. To gain more insight on the component processes implied in the task, performance data (accuracy and speed) were not only analyzed separately but also submitted to a diffusion model analysis. The main findings indicated that the left prefrontal patients were impaired in appropriately adopting stricter response criteria in speed-to-accuracy switching trials with respect to healthy controls and right prefrontal patients, who were not impaired in this condition. This study demonstrates that the prefrontal cortex in the left hemisphere is necessary for flexible behavioral regulations, in particular when setting stricter response criteria is required in order to successfully switch from a speedy strategy to an accurate one.

Comprehensive craniospinal radiation for controlling central nervous system leukemia

PURPOSE

To determine the benefit of radiation therapy (RT) in resolution of neurologic symptoms and deficits and whether the type of RT fields influences central nervous system (CNS) control in adults with CNS leukemia.

METHODS AND MATERIALS

A total of 163 adults from 1996 to 2012 were retrospectively analyzed. Potential associations between use of radiation and outcome were investigated by univariate and multivariate analysis.

RESULTS

The median survival time was 3.8 months after RT. Common presenting symptoms were headache in 79 patients (49%), cranial nerve VII deficit in 46 (28%), and cranial nerve II deficit in 44 (27%). RT was delivered to the base of skull in 48 patients (29%), to the whole brain (WB) in 67 (41%), and to the craniospinal axis (CS) in 48 (29%). Among 149 patients with a total of 233 deficits, resolution was observed in 34 deficits (15%), improvement in 126 deficits (54%), stability in 34 deficits (15%), and progression in 39 deficits (17%). The 12-month CNS progression-free survival was 77% among those receiving CS/WB and 51% among those receiving base of skull RT (P=.02). On multivariate analysis, patients who did not undergo stem cell transplantation after RT and base of skull RT were associated with worse CNS progression-free survival.

CONCLUSIONS

Improvement or resolution of symptoms occurred in two thirds of deficits after RT. Comprehensive radiation to the WB or CS seems to offer a better outcome, especially in isolated CNS involvement.

Neurosymptomatic carvenous sinus meningioma: a 15-years experience with fractionated stereotactic radiotherapy and radiosurgery

BACKGROUND

The tumor removal of Cavernous Sinus Meningiomas usually results in severe neurological deficits. Stereotactic radiosurgery (SRS) and fractionated Stereotactic radiotherapy (SRT) are advanced modalities of radiotherapy for treatment of patients with inoperable and symptomatic CSMs. The authors evaluated the long term symptomatology, the image findings, and the toxicity of patients with CSMs treated with SRS or SRT.

PATIENTS AND METHODS

From 1994 to 2009, 89 patients with symptomatic CSMs were treated with SRS or SRT. The indication was based on tumour volume and or proximity to the optic chiasm. The median single dose of SRS was 14 Gy, while the SRT total dose, ranged from 50.4 to 54 Gy fractionated in 1.8-2 Gy/dose. The median follow-up period lasted 73 months.

RESULTS

The clinical and radiological improvement was the same despite the method of radiotherapy; 41.6% (SRS) and 48.3% (SRT) of patients treated. The disease-free survivals were 98.8%, 92.3% and 92.3%, in 5, 10, and 15 years, respectively. There was no statistical difference in relation to the symptoms and image findings between both methods. According to the Common Toxicity Criteria, 7% of the patients presented transient optic neuropathy during 3 months (grade 2) and recovered with dexamethasone, 2 patients had trigeminal neuropathy (grade 2) and improved rapidly, and one patient presented total occlusion of the internal carotid artery without neurological deficit (grade 2). Temporary lethargy and headache (grade 1) were the most frequent immediate complications. No severe complications occurred.

CONCLUSIONS

Stereotactic Radiosurgery and fractionated Stereotactic Radiotherapy were equally safe and effective in the management of symptomatic CSMs.

Controversies in radiotherapy for meningioma

Meningiomas are the most common primary intracranial tumour. Although external beam radiotherapy and radiosurgery are well-established treatments, affording local control rates of 85-95% at 10 years, the evidence base is mainly limited to single institution case series. This has resulted in inconsistent practices. It is generally agreed that radiotherapy is an established primary therapy in patients requiring treatment for surgically inaccessible disease and postoperatively for grade 3 tumours. Controversy exists surrounding whether radiotherapy should be upfront or reserved for progression for incompletely excised and grade 2 tumours. External beam radiotherapy and radiosurgery have not been directly compared, but seem to offer comparable rates of control for benign disease. Target volume definition remains contentious, including the inclusion of hyperostotic bone, dural tail and surrounding brain, but pathological studies are shedding some light. Most agree that doses around 50-54 Gy are appropriate for benign meningiomas and ongoing European Organization for Research and Treatment of Cancer and Radiation Therapy Oncology Group studies are evaluating dose escalation for higher risk disease. Here we address the 'who, when and how' of radiotherapy for meningioma.

Long-term impact of cognitive deficits and epilepsy on quality of life in patients with low-grade meningiomas

BACKGROUND

WHO Grade I meningiomas are common, usually benign, primary brain tumors. Little is known about the health-related quality of life (HRQOL) of patients with meningiomas.

OBJECTIVE

To investigate the long-term HRQOL in patients with meningiomas and its association with cognitive deficits and epilepsy.

METHODS

HRQOL was assessed by the Short-Form Health Survey questionnaire (SF-36) in 89 patients with WHO Grade I meningiomas at least 1 year following neurosurgery with or without radiotherapy. Cognitive functioning was measured by a neuropsychological test battery, and epileptic seizure frequency and antiepileptic drug (AED) use were determined for each patient. HRQOL of patients was compared to that of 89 healthy controls individually matched for age, sex, and educational level.

RESULTS

As a group, patients with meningiomas did not differ from healthy controls on 7 out of 8 SF-36 scales; the only difference was that patients reported more role limitations caused by physical problems (P < .05). Patients with meningiomas had significant impairment in 4 of 6 cognitive domains, most pronounced in the domain of executive functioning. Both impaired cognitive functioning and AED use were associated with a compromised HRQOL. Of the 23 patients using AEDs, HRQOL was significantly impaired on 5 out of 8 SF-36 scales. In patients using AED, neither cognitive functioning nor HRQOL differed between those with and those without seizure control.

CONCLUSION

The HRQOL of most patients with WHO Grade I meningiomas is comparable to that of the general population. However, HRQOL is worse in patients with major cognitive deficits and those using AEDs, irrespective of seizure control.

Neurocognitive functioning and health-related quality of life in patients with radiologically suspected meningiomas

Few data are available concerning the neurocognitive outcome and health-related quality of life (HRQOL) following neurosurgery in meningioma patients, and even less is known about neurocognitive functioning and HRQOL in untreated patients with stable lesions. The present study aims at quantifying the nature and extent of neurocognitive deficits and HRQOL in suspected WHO grade I meningioma patients who have not received surgery and/or radiotherapy and compare outcome to that of healthy controls. Neurocognitive functioning was assessed by using a standardized test battery in 21 radiologically suspected WHO grade I meningioma patients with a wait-and-scan approach. HRQOL was assessed with the MOS SF-36 questionnaire. These patients were matched for age, sex, and education with 21 healthy controls. Associations between neurocognitive functioning on the one hand and HRQOL and tumor characteristics on the other were determined. Compared to healthy controls, meningioma patients had lower psychomotor speed (p = 0.011) and working memory capacity (p = 0.034) and furthermore attained lower levels of self-perceived general health and vitality. Neurocognitive functioning in untreated patients was not related to tumor volume, edema or tumor lateralization. No correlations were found between psychomotor speed or working memory and HRQOL. Untreated meningioma patients with stable lesions have limitations in neurocognitive functioning and HRQOL. In deciding upon a treatment strategy these reductions in functioning should be taken into consideration and communicated with the patient.

State-of-the-art treatment alternatives for base of skull meningiomas: complementing and controversial indications for neurosurgery, stereotactic and robotic based radiosurgery or modern fractionated radiation techniques

For skull base meningiomas, several treatment paradigms are available: Observation with serial imaging, surgical resection, stereotactic radiosurgery, radiation therapy or some combination of both. The choice depends on several factors. In this review we evaluate different treatment options, the outcome of modern irradiation techniques as well as the clinical results available, and establish recommendations for the treatment of patients with skull-base meningiomas.

Evolution and future of skull base surgery: the paradigm of skull base meningiomas

BACKGROUND

Skull base meningiomas represent the paradigm for the evolution of skull base surgery within the past 50 years into a distinct neurosurgical subspecialty.

METHODS

From 2005 to 2011, 117 patients with cranial base meningiomas underwent surgical resection. Extent of resection, histologic grade, complications, functional status, and recurrence-free and overall survival data are presented.

RESULTS

The summary rate of gross total resection was 53.0%. The surgical complication and mortality rates were 17.9% and 0.9%, respectively. Five-year recurrence-free survival was 88.0% for grade I meningiomas. A total of 90.3% of patients had a Karnofsky performance score ≥ 80 at last follow-up.

CONCLUSIONS

A large contemporary series of skull base meningiomas is presented. In addition, the evolution of surgical approaches to skull base meningiomas is reviewed, together with the current issues regarding radiation therapy, management of cavernous sinus tumor, oncologic management of atypical and malignant subtypes, molecular genetics, and future therapeutic options.

Gamma Knife surgery of meningiomas located in the posterior fossa: factors predictive of outcome and remission

Object

Although numerous studies have analyzed the role of stereotactic radiosurgery for intracranial meningiomas, few studies have assessed outcomes of posterior fossa meningiomas after stereotactic radiosurgery. In this study, the authors evaluate the outcomes of posterior fossa meningiomas treated with Gamma Knife surgery (GKS). The authors also assess factors predictive of new postoperative neurological deficits and tumor progression.

Methods

A retrospective review was performed of a prospectively compiled database documenting the outcomes of 152 patients with posterior fossa meningiomas treated at the University of Virginia from 1990 to 2006. All patients had a minimum follow-up of 24 months. There were 30 males and 122 females, with a median age of 58 years (range 12–82 years). Seventy-five patients were treated with radiosurgery initially, and 77 patients were treated with GKS after resection. Patients were assessed clinically and radiographically at routine intervals following GKS. Factors predictive of new neurological deficit following GKS were assessed via univariate and multivariate analysis, and Kaplan-Meier analysis and Cox multivariate regression analysis were used to assess factors predictive of tumor progression.

Results

Patients had meningiomas centered over the tentorium (35 patients, 23%), cerebellopontine angle (43 patients, 28%), petroclival region (28 patients, 18%), petrous region (6 patients, 4%), and clivus (40 patients, 26%). The median follow-up was 7 years (range 2–16 years). The mean preradiosurgical tumor volume was 5.7 cm3 (range 0.3–33 cm3), and mean postradiosurgical tumor volume was 4.9 cm3 (range 0.1–33 cm3). At last follow-up, 55 patients (36%) displayed no change in tumor volume, 78 (51%) displayed a decrease in volume, and 19 (13%) displayed an increase in volume. Kaplan-Meier analysis demonstrated radiographic progression-free survival at 3, 5, and 10 years to be 98%, 96%, and 78%, respectively. In Cox multivariable analysis, pre-GKS covariates associated with tumor progression included age greater than 65 years (hazard ratio [HR] 3.24, 95% CI 1.12–9.37; p = 0.03) and a low dose to the tumor margin (HR 0.76, 95% CI 0.60–0.97; p = 0.03), and post-GKS covariates included shunt-dependent hydrocephalus (HR 25.0, 95% CI 3.72–100.0; p = 0.001). At last clinical follow-up, 139 patients (91%) demonstrated no change or improvement in their neurological condition, and 13 patients showed symptom deterioration (9%). In multivariate analysis, the only factors predictive of new or worsening symptoms were clival or petrous location (OR 4.0, 95% CI 1.1–13.7; p = 0.03).

Conclusions

Gamma Knife surgery offers an acceptable rate of tumor control for posterior fossa meningiomas and accomplishes this with a low incidence of neurological deficits. In patients selected for GKS, tumor progression is associated with age greater than 65 years and decreasing dose to the tumor margin. Clival- or petrous-based locations are predictive of an increased risk of new or worsening neurological deficit following GKS.

Radiation dose-volume effects in the brain

We have reviewed the published data regarding radiotherapy (RT)-induced brain injury. Radiation necrosis appears a median of 1-2 years after RT; however, cognitive decline develops over many years. The incidence and severity is dose and volume dependent and can also be increased by chemotherapy, age, diabetes, and spatial factors. For fractionated RT with a fraction size of <2.5 Gy, an incidence of radiation necrosis of 5% and 10% is predicted to occur at a biologically effective dose of 120 Gy (range, 100-140) and 150 Gy (range, 140-170), respectively. For twice-daily fractionation, a steep increase in toxicity appears to occur when the biologically effective dose is >80 Gy. For large fraction sizes (>or=2.5 Gy), the incidence and severity of toxicity is unpredictable. For single fraction radiosurgery, a clear correlation has been demonstrated between the target size and the risk of adverse events. Substantial variation among different centers' reported outcomes have prevented us from making toxicity-risk predictions. Cognitive dysfunction in children is largely seen for whole brain doses of >or=18 Gy. No substantial evidence has shown that RT induces irreversible cognitive decline in adults within 4 years of RT.

Acute neurocognitive impairment during cranial radiation therapy in patients with intracranial tumors

BACKGROUND AND PURPOSE

The objective of the current study was to evaluate the acute effects of cranial radiation therapy (CNS-RT) using different radiation doses (0, 1.8, 2, 3, >or=20 Gy) on cognitive function with special emphasis on memory. We assessed patients with and without intracranial tumors to distinguish between direct and indirect radiation effects on brain tissue.

MATERIALS AND METHODS

Eighty-two patients were evaluated with neuropsychological testing before and acutely after radiotherapy (RT). Sixty-four patients received RT to the brain (55 with, 9 without intracranial tumor). Eighteen patients treated with RT to the breast served as controls.

RESULTS

Patients with intracranial tumor demonstrated attention (19-38th percentile) and verbal memory scores (34-46th percentile) below the population average at baseline. The average Verbal Memory score was significantly different between patients with intracranial tumor and controls both at baseline (38th vs. 58th percentile) and after irradiation (27th vs. 52th percentile). Patients with preexisting peritumoral edema performed worse than patients without edema and controls. Radiation dose-related deficits were seen for working memory performance in patients with intracranial tumor.

CONCLUSION

Our data indicate no measurable impairment of cognitive functioning acutely after prophylactic cranial irradiation. Patients with intracranial tumor show a deterioration of almost all memory functions with a dose-dependent impairment in working memory. Patients with preexisting peritumoral brain edema show the strongest deterioration.

Memory function before and after whole brain radiotherapy in patients with and without brain metastases

PURPOSE

To prospectively compare the effect of prophylactic and therapeutic whole brain radiotherapy (WBRT) on memory function in patients with and without brain metastases.

METHODS AND MATERIALS

Adult patients with and without brain metastases (n = 44) were prospectively evaluated with serial cognitive testing, before RT (T0), after starting RT (T1), at the end of RT (T2), and 6-8 weeks (T3) after RT completion. Data were obtained from small-cell lung cancer patients treated with prophylactic cranial irradiation, patients with brain metastases treated with therapeutic cranial irradiation (TCI), and breast cancer patients treated with RT to the breast.

RESULTS

Before therapy, prophylactic cranial irradiation patients performed worse than TCI patients or than controls on most test scores. During and after WBRT, verbal memory function was influenced by pretreatment cognitive status (p < 0.001) and to a lesser extent by WBRT. Acute (T1) radiation effects on verbal memory function were only observed in TCI patients (p = 0.031). Subacute (T3) radiation effects on verbal memory function were observed in both TCI and prophylactic cranial irradiation patients (p = 0.006). These effects were more pronounced in patients with above-average performance at baseline. Visual memory and attention were not influenced by WBRT.

CONCLUSIONS

The results of our study have shown that WBRT causes cognitive dysfunction immediately after the beginning of RT in patients with brain metastases only. At 6-8 weeks after the end of WBRT, cognitive dysfunction was seen in patients with and without brain metastases. Because cognitive dysfunction after WBRT is restricted to verbal memory, patients should not avoid WBRT because of a fear of neurocognitive side effects.

Diffusion tensor imaging screening of radiation-induced changes in the white matter after prophylactic cranial irradiation of patients with small cell lung cancer: first results of a prospective study

BACKGROUND AND PURPOSE

Diffusion tensor imaging (DTI) will show abnormal fractional anisotropy (FA) in the normal-appearing brain after prophylactic cranial irradiation (PCI). These abnormalities will be more accentuated in patients with underlying vascular risk factors.

MATERIALS AND METHODS

A prospective study by use of DTI and conventional T2-weighted MR images was performed with a 1.5T unit with 16 patients with small cell lung cancer and undergoing PCI. All of the T2-weighted images were evaluated with respect to abnormalities in signal intensity of white matter as markers of radiation damage. Measurements of FA were performed before, at the end of, and 6 weeks after radiation therapy. On the FA maps, the bifrontal white matter, the corona radiata, the cerebellum, and the brain stem were evaluated. FA values were compared with respect to age, demographic, and vascular risk factors. Statistical analyses (Friedman test, Wilcoxon test, and Mann-Whitney U test) were performed.

RESULTS

Fractional anisotropy decreased significantly in supratentorial and infratentorial normal-appearing white matter from the beginning to the end of PCI (P < .01). A further decline in FA occurred 6 weeks after irradiation (P < .05). A stronger reduction in FA was observed in patients with more than 1 vascular risk factor. There was an age-related reduction of white matter FA. Patients 65 years and older showed a trend toward a stronger reduction in FA.

CONCLUSION

During the acute phase, after PCI, patients with many vascular risk factors showed stronger damage in the white matter compared with patients with only 1 risk factor.

Role of radiation therapy in treating intracranial meningiomas

Surgery is the mainstay for many patients with meningiomas, and it remains the standard. In large single-institution series, gross-total resection has been reported to achieve 5-, 10-, and 15-year recurrence-free survival rates of approximately 90, 80, and 70%, respectively. There are a growing number of series of patients with prolonged follow-up in which authors have evaluated fractionated external-beam radiation therapy (EBRT) either as an adjuvant to surgery for subtotally resected, recurrent, or higher-grade meningiomas, or as an alternative to surgery. The primary focus of this review is EBRT, but to lend perspective, a comparative analysis of surgery and radiosurgery is also provided.

New prospects for management and treatment of inoperable and recurrent skull base meningiomas

Skull base, including optic nerve, cavernous sinus, clival and foramen magnum tumors represent a major challenge for neurosurgeons and neuro-oncologists. Growth regulatory signaling pathways for these tumors are of increasing interest as potential targets for new chemotherapy. Those differentially activated in various grades of meningiomas are currently being identified as well. This article reviews some recent findings pathways that appear to regulate meningioma growth. Potential targets for novel therapies are also discussed.

Fractionated stereotactic radiotherapy in the treatment of exclusive cavernous sinus meningioma: functional outcome, local control, and tolerance

BACKGROUND

Fractionated stereotactic radiotherapy (FSRT) combines the precision of stereotactic positioning with the radiobiologic advantage of dose fractionation.

METHODS

From June 1997 to June 2001, 30 patients with cavernous sinus meningiomas were treated with FSRT using fixed noncoplanar conformal fields. Patient skull fixation was achieved using the BrainLAB mask (20 patients) or Beverly frame (10 patients). The Cosman-Roberts-Wells coordinate frame was used for stereotactic space definition. In selected cases before 1999, and in all cases afterward, gadolinium-enhanced MRI for image fusion was performed. The median radiation dose was 52 Gy, with a daily fraction of 2 Gy. Patients were regularly followed up analyzing symptoms, tumor progression, and side effects. Neurocognitive function was evaluated retrospectively for 26 patients using Mini-Mental State Examination.

RESULTS

Median follow-up period was 50 months (range, 28.2-74.5 months). Preexisting neurologic symptoms improved in 50% of the patients and worsened in 2 patients. Only 2 patients progressed and the actuarial local progression free survival was 93% at 4 years. Tolerance was good with 2 cases of late radiation toxicity which consisted of moderate short-term memory loss and dysphasia in one case and neuropsychologic deficit with seizures in the other. Postradiotherapy Mini-Mental State Examination results showed a median score of 28 (range, 16-30).

CONCLUSIONS

Fractionated stereotactic radiotherapy is a high-precision technique. It is safe and feasible in the primary and adjuvant treatment of cavernous sinus meningiomas. Fractionated stereotactic radiotherapy allowed local control in more than 90% of patients.

Cognitive sequelae of brain tumor treatment

PURPOSE OF REVIEW

The neurocognitive sequelae of anticancer treatment have received increasing attention especially among individuals with low-grade gliomas, primary central nervous system lymphoma and those undergoing prophylactic cranial irradiation for systemic malignancies. These groups are especially vulnerable because they often experience extended survival during which neurocognitive complications of therapy may cause more impairment than the tumor itself. The purpose of this review is to highlight recent clinical reports of neurocognitive sequelae among patients without significant central nervous system tumor burden and to describe the experimental studies which may explain the pathogenesis of the disorder.

RECENT FINDINGS

The neurocognitive deficits among survivors of primary central nervous system lymphoma without residual tumor and pituitary tumors were reported recently. Both provide an opportunity to distinguish the effects of treatment from the effects of tumor. Moreover, animal studies demonstrate the negative consequences of radiation on hippocampal neurogenesis, learning and memory. The mechanism of impaired neurogenesis may be due to inflammation, which can be aborted with restoration of neurogenesis through the administration of non-steroidal anti-inflammatory agents.

SUMMARY

If inhibition of neurogenesis is the basis of neurocognitive sequelae from irradiation and non-steroidal anti-inflammatory agents can restore neurogenesis then a clinical trial may be worthwhile to confirm this benefit in humans.