Quality-of-life assessment in patients who had been surgically treated for cerebellar pilocytic astrocytoma in childhood

The tumour microenvironment of pilocytic astrocytoma evolves over time via enrichment for microglia

Pilocytic astrocytoma (PA) is the commonest low-grade tumour affecting children and is frequently experienced as a chronic disease associated with extended treatment, periods of regrowth, and long-term disability. This contrasts with the view of PA as a benign tumour with positive clinical outcomes and raises the fundamental question of biologically driven change over time within these tumours, which will impact diagnosis, stratification, and management. To investigate the molecular, cellular, and pathological stability of PA we performed RNA sequencing, methylation array profiling, immunohistochemistry, and targeted panel DNA sequencing on a cohort of 15 PA patients with matched primary/longitudinal samples at a mean sampling interval of 2.7 years. Through pairwise analysis of primary versus longitudinal tumour samples we identified changes to immune-related pathways within the expression and methylation profiles of longitudinal PA. Further interrogation of these changes revealed an enrichment over time for microglial cell populations, which was validated by immunohistochemistry against common monocyte/microglial markers. Moreover, immunohistochemical characterisation revealed concurrent increases in the expression of M2-like and anti-inflammatory markers. Microglial enrichments were consistent across the cohort and were not adequately explained by a range of potential confounders, including receipt of adjuvant therapy. Taken together, these data challenge the idea of pilocytic astrocytoma as a static entity and indicate that they consistently accumulate microglia over time, potentially co-opting the immune microenvironment towards an anti-inflammatory phenotype that may affect the natural course and treatment response of the tumours.

Quality of life reporting in the management of posterior fossa tumours: A systematic review

Introduction

Survival amongst posterior fossa tumour (PFT) patients is improving. Clinical endpoints such as overall survival fail to depict QoL. There is yet to be a review of current QoL instruments used for adult PFTs. Aim of this review is to outline the QoL reporting in the management of PFTs and measure participation level.

Methods

This systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis. A search strategy to identify adult patients with PFTs who took part in QoL metrics was conducted. Observational and experimental studies published from 1990 to date were included. Studies with a sample size less than 10 and performance measures such as Karnofsky Performance Status were not considered.

Results

A total of 116 studies were included in the final analysis. Vestibular schwannomas were the most common tumour pathology (n = 23,886, 92.6%) followed by pilocytic astrocytomas (n = 657, 2.5%) and meningiomas (n = 437, 1.7%) Twenty-five different QoL measures were used in the study pool. SF-36 was the most common (n = 55, 17 47.4%) QoL metric in the whole study pool, followed by the Penn Acoustic Neuroma QoL scale (n = 24, 20.7%) and Dizziness Handicap Inventory (n = 16, 13.8%). Seventy-two studies reported less-than 100% participation in QoL evaluation. The commonest reason for non-participation was a lack of response (n = 1,718, 60.8%), incomplete questionnaires (n = 268, 9.4%) and cognitive dysfunction (n = 258, 9.1%).

Conclusion

Informed clinical decision-making in PFT patients requires the development of specific QoL outcomes. Core outcome sets, and minimal clinically important differences (MCID) are essential for these metrics to show clinically significant improvements in patient QoL.

Employment among Childhood Cancer Survivors: A Systematic Review and Meta-Analysis

To date, there are heterogeneous studies related to childhood cancer survivors’ (CCS) employment rates. Given the importance of this topic, we aimed to perform a systematic review and meta-analysis to investigate the prevalence of employment among CCS and to examine its association with socio-demographic and clinical factors. We followed the PRISMA guidelines to search for pertinent articles in relevant electronic databases. Eighty-nine articles comprising 93 cohorts were included. The overall prevalence of employment was 66% (CI: 95% 0.63–0.69). Subgroup meta-analyses showed that lower rates were found for central nervous system tumor survivors (51%, CI: 95% 0.43–0.59), and for CCS treated with cranial-radiotherapy (53%, CI: 95% 0.42–0.64) or haematopoietic stem-cell transplantation (56%, CI: 95% 0.46–0.65). The studies conducted in Asia highlighted employment rates of 47% (CI: 95%, 0.34–0.60). Univariate meta-regressions identified the following socio-demographic factors associated with higher rates of employment: a female gender (p = 0.046), a higher mean age at the time of investigation (p = 0.00), a longer time since diagnosis (p = 0.00), a higher educational level (p = 0.03), and a married status (p = 0.00). In conclusion, this systematic review and meta-analysis provides evidence that two-thirds of CCS are employed worldwide. Identifying vulnerable groups of CCS may allow for the design of multidisciplinary support strategies and interventions to promote employment in this population.

The role of cerebellum in the child neuropsychological functioning

This chapter proposes a review of neuropsychologic and behavior findings in pediatric pathologies of the cerebellum, including cerebellar malformations, pediatric ataxias, cerebellar tumors, and other acquired cerebellar injuries during childhood. The chapter also contains reviews of the cerebellar mutism/posterior fossa syndrome, reported cognitive associations with the development of the cerebellum in typically developing children and subjects born preterm, and the role of the cerebellum in neurodevelopmental disorders such as autism spectrum disorders and developmental dyslexia. Cognitive findings in pediatric cerebellar disorders are considered in the context of known cerebellocerebral connections, internal cellular organization of the cerebellum, the idea of a universal cerebellar transform and computational internal models, and the role of the cerebellum in specific cognitive and motor functions, such as working memory, language, timing, or control of eye movements. The chapter closes with a discussion of the strengths and weaknesses of the cognitive affective syndrome as it has been described in children and some conclusions and perspectives.

Neuropsychological and socioeconomic outcomes in adult survivors of pediatric low-grade glioma

BACKGROUND

Current estimates suggest that 75% of children diagnosed with a central nervous system (CNS) tumor will become 5-year survivors. However, survivors of childhood CNS tumors are at increased risk for long-term morbidity.

METHODS

To determine long-term neuropsychological and socioeconomic status (SES) outcomes, adult survivors of pediatric low-grade gliomas (n = 181) in the Childhood Cancer Survivor Study and a sibling comparison group that was frequency-matched by age and sex (n = 105) completed a comprehensive battery of standardized neuropsychological tests and an SES assessment. Multivariable regression models compared treatment-specific groups for neuropsychological and SES outcomes and evaluated associations with tumor location, age at diagnosis, sex, and age at evaluation.

RESULTS

In adjusted models, survivors treated with surgery and radiotherapy (surgery+RT; median age at diagnosis, 7 years; median age at assessment, 41 years) scored lower on estimated IQ than survivors treated with surgery only, who scored lower than siblings (surgery+RT, 93.9; surgery only, 101.2; siblings, 108.5; all P values <.0001). Survivors diagnosed at younger ages had low scores for all outcomes (P < .05) except for attention/processing speed. For SES outcomes, survivors treated with surgery+RT had lower occupation scores (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.1-5.9), lower income (OR, 2.6; 95% CI, 1.3-5.0), and less education (OR, 2.1; 95% CI, 1.1-4.0) than those treated with surgery only.

CONCLUSIONS

Decades after treatment, survivors treated with radiotherapy and at younger ages had poorer neuropsychological and SES outcomes. Lifelong surveillance of survivors of pediatric low-grade gliomas may be warranted as life events, stages, and transitions (employment, family, and aging) present new challenges and risks.

Cerebellar pilocytic astrocytoma in childhood: Investigating the long-term impact of surgery on cognitive performance and functional outcome

OBJECTIVE

Previous studies differ regarding the long-term effects of surgically removed pediatric cerebellar pilocytic astrocytomas (CPA). Thus, the aim of this study was to investigate the long-term impact on neurocognitive and functional outcome and to analyze age as an influencing factor.

METHODS

Fourteen CPA patients were compared to the age norm and to a group of 14 high-achieving peers regarding cognitive functioning, health-related quality of life (HRQoL), and stress regulation. Mean follow-up time after diagnosis was 13.29 years (range: 3-21 years).

RESULTS

Patients showed satisfactory academic achievement and did not differ from the norm except for the bodily dimension of HRQoL. However, there were marked differences in specific neurocognitive functions between patients and high achievers. Age at diagnosis did not influence neurocognitive outcome.

CONCLUSION

CPA patients treated with surgery only seem to have a favorable long-term outcome, yet, in comparison with high achievers specific cognitive impairments become apparent.

Impact of attention on social functioning in pediatric medulloblastoma survivors

BACKGROUND

Parent-reported attention problems have been associated with social functioning in a broad sample of pediatric cancer survivors.

OBJECTIVE

The present study focused on a more homogeneous sample (pediatric medulloblastoma survivors), with the novel inclusion of self-reported attention ratings.

PARTICIPANTS/METHODS

Thirty-three pediatric medulloblastoma survivors, ages 7-18 years, completed a brief IQ measure and self-report of attentional and social functioning. Parents rated patients' attentional and social functioning.

RESULTS

Mean attention ratings were average based on both parent- and self-report, though parent ratings were significantly discrepant from normative means. No significant demographic or treatment-related predictors of self-reported attention problems were identified, whereas female gender was associated with greater parent-reported attention problems. Canonical correlation analysis revealed a significant association between parent-reported attention difficulties and social functioning in pediatric medulloblastoma survivors, but there was no association between self-reported attention problems and measures of social functioning.

CONCLUSIONS

Consistent with existing literature in broader samples of pediatric cancer survivors, the present study further affirms attention deficits as an underlying contributor to social deficits in pediatric medulloblastoma survivors while also finding little relationship between self-reports of attention and social performance. Notably, present findings provide additional support suggesting that attention functioning is a more significant contributor to social outcomes for pediatric medulloblastoma survivors than the level of cognitive ability.

Systematic review and meta-analysis of health-related quality of life in pediatric CNS tumor survivors

BACKGROUND

Pediatric central nervous system (CNS) tumor survivors are at high risk for numerous late effects including decreased health-related quality of life (HRQOL). Our objective was to summarize studies describing HRQOL in pediatric CNS tumor survivors and compare HRQOL outcomes in studies that included a comparison group.

PROCEDURE

EMBASE, MEDLINE, and PsychINFO were used to identify relevant articles published until August, 2016. Eligible studies reported outcomes for pediatric CNS tumor survivors diagnosed before age 21, at least 5 years from diagnosis and/or 2 years off therapy and used a standardized measure of HRQOL. All data were abstracted by two reviewers. Random-effects meta-analyses were performed using Review Manager 5.0.

RESULTS

Of 1,912 unique articles identified, 74 were included in this review. Papers described 29 different HRQOL tools. Meta-analyses compared pediatric CNS tumor survivors to healthy comparisons and other pediatric cancer survivors separately. HRQOL was significantly lower for CNS (n = 797) than healthy comparisons (n = 1,397) (mean difference = -0.54, 95% confidence interval [CI] = -0.72 to -0.35, P < 0.001, I² = 35%). HRQOL was also significantly lower for CNS (n = 244) than non-CNS survivors (n = 414) (mean difference = -0.56, 95% CI = -0.73 to -0.38, P < 0.00001, I² = 0%).

CONCLUSIONS

Pediatric CNS tumor survivors experience worse HRQOL than healthy comparisons and non-CNS cancer survivors. Future HRQOL work should be longitudinal, and/or multisite studies that examine HRQOL by diagnosis and treatment modalities.

"She Was a Little Social Butterfly": A Qualitative Analysis of Parent Perception of Social Functioning in Adolescent and Young Adult Brain Tumor Survivors

Psychosocial sequelae of diagnosis and treatment for childhood brain tumor survivors are significant, yet little is known about their impact on adolescent and young adult (AYA) brain tumor survivors. Interviews were conducted with parents of AYA brain tumor survivors with a focus on social functioning. Semistructured interviews were conducted with English- and Spanish-speaking parents of AYA brain tumor survivors ≥10 years of age who were >2 years postdiagnosis, and analyzed using emergent themes theoretically integrated with a social neuroscience model of social competence. Twenty parents representing 19 survivors with a survivor mean age 15.7 ± 3.3 years and 10.1 ± 4.8 years postdiagnosis were interviewed. Several themes relevant to the social neuroscience social competence model emerged. First, parents' perceptions of their children's impaired social functioning corroborated the model, particularly with regard to poor social adjustment, social withdrawal, impaired social information processing, and developmentally inappropriate peer communication. Second, ongoing physical and emotional sequelae of central nervous system insults were seen by parents as adversely affecting social functioning among survivors. Third, a disrupted family environment and ongoing parent psychosocial distress were experienced as salient features of daily life. We document that the aforementioned framework is useful for understanding the social impact of diagnosis and treatment on AYA brain tumor survivorship. Moreover, the framework highlights areas of intervention that may enhance social functioning for AYA brain tumor survivors.

Health-related quality of life and emotional problems in children surviving brain tumor treatment: A descriptive study of 2 cohorts

The survival of childhood brain tumors has improved in the past 30 years, but acquired brain injury due to damage caused by tumor invasion and side effects of different treatment modalities frequently occurs. This study focused on residual impairments, health-related quality of life (HRQoL), and emotional and behavioral problems in 2 cohorts of survivors diagnosed and treated for various types of brain tumors. Survivors in the 2004 cohort visited the Erasmus Medical Centre for standardized follow-up between 2003 and 2004, and in the 2014 cohort, between 2012 and 2014. Data of neurologically impairments of all children were extracted from medical records. Parents and survivors filled out questionnaires on quality of life and emotional and behavioral problems. In both cohorts, approximately 55% of the survivors displayed neurologic impairments. In comparison with the healthy reference group, a reduced parent-reported quality of life was found on the Motor, Cognition, and Autonomy (Cohort 2004) scales. Comparison between the cohorts showed that parents in the 2004 cohort reported a higher HRQoL on the Motor and Cognitive functioning scales. In the 2014 cohort, children reported less negative emotions than healthy children. No increase in emotional or behavioral problems were reported by children in both cohorts, whereas parents reported problems in social functioning and isolation related to a delay in emotional development. Children surviving brain tumor treatment have a reduced quality of life. The authors therefore recommend regular screening of HRQoL and emotional and behavioral problems and referral to specific aftercare.

Social competence in pediatric brain tumor survivors: breadth versus depth

PURPOSE OF REVIEW

The purpose of this article is to review the literature in the area of social competence in pediatric brain tumor survivors published in the last year.

RECENT FINDINGS

Research published over the past year examining the social competence of pediatric brain tumor survivors has seen the consistent application of a comprehensive conceptual framework that pertains specifically to children with brain disorders. Subsequent to the application of a comprehensive conceptual framework, more sophisticated research approaches have begun to advance our understanding of deficits among this population. Specifically, operationalization of social competence is evolving.

SUMMARY

Continued application of a conceptual framework and investigation into the components that comprise the framework will enhance the depth of our understanding of social competence deficits among this population. Research must continue to use innovative approaches to measuring social competence. Considerable gaps still exist with respect to identifying risk and resilience factors for social competence deficits.

Prospective longitudinal evaluation of emotional and behavioral functioning in pediatric patients with low-grade glioma treated with conformal radiation therapy

Patients with low-grade glioma (LGG) who are successfully treated with irradiation are at increased risk for cognitive and psychosocial late effects. Conformal radiation therapy (CRT) allows sparing of cognitive deficits, but how it affects emotional and behavioral functioning remains unclear. We performed a prospective longitudinal study of the emotional and behavioral functioning of pediatric patients with LGG in the first 5 years post-CRT. Ninety-five pediatric patients with LGG treated on an institutional Phase II trial (August 1997-June 2009) underwent neuropsychological assessments pre-CRT and 6, 12, 24, 36, 48, and 60 months post-CRT. Parent-reported scores on the Child Behavior Checklist (CBCL) were analyzed. Three competence scales (School Competence, Social Competence, and Activities), two summary scales (Internalizing Problems and Externalizing Problems), and two subscales of theoretical interest (Attention Problems and Social Problems) from the CBCL were used. Among 80 eligible patients [44 female, 68 white], 51 had pilocytic astrocytoma and 13 had optic pathway glioma. Mean age at diagnosis was 6.8 years (SD = 4.3 years) and at CRT initiation was 8.9 years (SD = 3.4 years). Before CRT, deficits were demonstrated on the competence scales (mean scores below normative mean) and the Attention Problems and Social Problems subscales (mean scores above normative means). This trend continued at 5 years post-CRT. Longitudinal trajectories of emotional and behavioral functioning were stable over 5 years. Emotional and behavioral deficits remain relatively stable over the 5 years post-CRT in patients with LGG, suggesting that CRT may not exacerbate pre-existing psychosocial difficulties in this population.

Central nervous system tumors

Central nervous system tumors are the most frequent malignant tumor in children and the main cause of death in this age group after traffic accidents. The current estimates are that one adult in 2500 is a survivor of a brain tumor that occurred during childhood. These tumors are particularly heterogeneous in terms of histology/biology, treatment, and outcome. They share, however, a high risk of neurological and cognitive morbidity due to the disease itself and the treatment modalities (radiotherapy, surgery, and chemotherapy). Diagnosis is frequently delayed because symptoms are usually nonspecific at the beginning of the evolution. Posterior fossa is the most frequent site and the tumors present most frequently with signs of intracranial hypertension. Supratentorial tumors are more frequent in infants and in adolescents; seizures are not uncommon, especially for benign tumors. When adjuvant treatment is needed, radiotherapy is usually the mainstay apart from some histologies where chemotherapy may be sufficient: low-grade gliomas, desmoplastic medulloblastomas, malignant glial tumors in infants. Multidisciplinary care is best performed in tertiary care centers and should include early rehabilitation programs soon after surgery.

Increased prevalence of chronic fatigue among survivors of childhood cancers: a population-based study

BACKGROUND

Fatigue is prevalent in adult cancer survivors but less studied in childhood cancer survivors. Aims were to assess fatigue levels, prevalence of chronic fatigue (CF) and the association of CF with health-related quality of life (HRQoL) in survivors of acute myeloid leukemia (AML), infratentorial astrocytoma (IA), and Wilms tumor (WT) in childhood.

PROCEDURE

Seventy percent (398/567) of Nordic patients treated for AML, IA, and WT between 1985 and 2001 at age >1 year responded to a postal survey, encompassing the Fatigue Questionnaire and the Short Form 36 (SF-36). Participants were divided into two groups at time of study; younger (YG, 13-18 years) and older (OG, 19-34 years). Respondents (19-34 years, n = 763) from a Norwegian general population (GP) survey served as controls for the OG.

RESULTS

The OG [mean age was 24 years (SD 3.3)] had higher fatigue levels compared to the YG and the GP, especially the females (P < 0.05). There was also a higher prevalence of CF in the OG than in the GP (14 vs. 6%, P < 0.001). Regardless of diagnosis, the OG with CF had poorer physical health (P < 0.05) on the SF-36 but better mental health (P < 0.05 and P = 0.001) relative to controls with CF.

CONCLUSIONS

The prevalence of CF is higher among Nordic survivors of AML, IA, and WT than GP controls of similar age. CF is associated with impaired HRQoL in survivors. However, they reported better mental health than CF GP controls. This might indicate different underlying mechanisms of CF in the two populations.

Neuropsychological Outcomes of Children Treated for Posterior Fossa Tumours:A Review

The posterior fossa region of the brain is a frequent site for tumour development in children, with over half of all childhood tumours occurring at this site. The principal brain structure implicated at this site is the cerebellum. Children treated for posterior fossa tumours can have a wide range of neurological and psychosocial problems. This paper describes the literature to date that addresses the neuropsychological impact of tumour and treatment in children with posterior fossa tumours. This paper reviews the literature on the causes of morbidity in this group. It discusses the recent research on the role of the cerebellum in outcomes and the studies that identify variables that interact with radiation effects.

Pediatric low-grade glioma survivors experience high quality of life

PURPOSE

The purpose of this study was to determine pediatric low-grade glioma survivors' quality of life and late morbidity including motor, sensory, and cognitive deficits.

METHODS

We surveyed 49 survivors and their parents (KINDL questionnaire).

RESULTS

Despite tumor and treatment-associated morbidity, survivors (25 boys and 24 girls, median age at diagnosis 7.8 years), but not their parents, rated their total quality of life higher than their peers. Although all survivors had some late morbidity, half of them were able to conduct their daily lives without restriction.

CONCLUSION

These results reflect survivors' effective coping mechanisms and underscore the difficulties of assessing quality of life in pediatric populations.

Outcome of children with low-grade cerebellar astrocytoma: long-term complications and quality of life

OBJECTS

To study the long-term outcome of surgically treated low-grade cerebellar astrocytomas in children.

MATERIALS AND METHODS

We followed 31 consecutive patients under 16 years of age who were diagnosed between 1980 and 2005 in a single institution. In 21 of 31 survivors (median follow-up time 7.9 years; range 5.6-27.4 years) who agreed to participate, tumor control, neurological and cognitive complications, and their impact on behavioral and emotional adjustment and health-related quality of life (HRQoL) were comprehensively assessed qualitatively and quantitatively.

RESULTS

Neurological sequelae were found in 43%. However, age-appropriate ability to perform daily life activities was normal in all patients. Remarkably, cognitive deficits leading to significant school problems occurred in 19% and behavioral and emotional adjustment disturbances in 27%. In comparison with healthy controls, the survivors rated their HRQoL similarly or even higher.

CONCLUSION

Childhood low-grade cerebellar astrocytomas have an excellent cure rate by tumor surgery alone. When compared with other pediatric brain tumors, the risk of neurological, cognitive, emotional, and behavioral complications is relatively small. HRQoL is similar to that of healthy controls.

Intelligence and adaptive function in children diagnosed with brain tumour during infancy

BACKGROUND

Late effects of treatment in children diagnosed and treated for brain tumours in infancy is a major concern. Assessment of infants presenting with brain tumours is difficult and there is little information available regarding the development of infants prior to treatment and hence the impact of the tumour itself on developmental outcomes.

AIM

To describe the development of children diagnosed with brain tumours in infancy and to document their cognitive and adaptive function at school entry.

METHOD

Infants were psychologically evaluated at the time of diagnosis of a brain tumour and during their fifth or sixth year in preparation for school entry.

RESULTS

Children diagnosed with brain tumours in infancy display developmental delays in a number of areas of adaptive function. By the time these children are school age they display further compromise in cognitive and academic skills and adaptive behaviour. Higher levels of deficit at follow-up were associated with tumour location in the supratentorium, younger age at diagnosis and longer time since diagnosis. The effect of radiotherapy could not be determined because of differing degrees of developmental compromise in the treatment groups at baseline.

CONCLUSION

Brain tumours in infancy confer a risk of poor developmental progress at the time of diagnosis. These children display additional compromise of development by the time they reach school age. Research protocols evaluating the impact of treatment in infants diagnosed with brain tumours need to take account of the developmental status of the child at diagnosis.

Functional outcome after low-grade astrocytoma treatment in childhood

BACKGROUND

The relatively high survival rate of patients with low-grade astrocytoma necessitates increasing attention to physical and psychosocial outcomes. The objective of the current study was to investigate functional outcomes among children who were treated for low-grade or pilocytic astrocytoma in different areas of the brain.

METHODS

Functional outcomes were evaluated in the following domains: impairments, disabilities, handicaps, and quality of life (QOL). In a consecutive series, 38 children were included. Follow-up ranged from 3 years and 7 months to 11 years and 4 months after diagnosis.

RESULTS

Approximately 61% of children had impairments and 10% had a severe disability. Handicaps were found in the domains of relationships, school, and behavior. Children who were treated for supratentorial tumors required significantly more special education, and children who were treated for infratentorial tumors had significantly more behavioral and social problems. QOL was decreased significantly in all domains except emotions. Children who had a diagnosis in adolescence reported a lower QOL in social functioning compared with younger children. Data analysis revealed that some deficits suddenly became apparent years after diagnosis.

CONCLUSIONS

At long-term follow-up, children who had low-grade or pilocytic astrocytomas were found to have poor functional outcomes, depending on tumor site, age, and recurrence. Children without deficits may develop severe cognitive, social, and behavioral deficits years after diagnosis, because of the phenomenon of "growing into deficit." Therefore, the authors suggest a long-term follow-up of children who are treated for low-grade or pilocytic astrocytomas at a young age to detect and subsequently offer support focused on the medical and cognitive impairments as well as on the behavioral and social consequences of their disease.

New Treatments in Pediatric Brain Tumors

The management of childhood brain tumors is likely to change dramatically during the next few years. Current treatment has improved outcome in some types of brain tumors, but for most patients, survival rates have not changed during the past two decades. Advances in surgery, radiation therapy, and chemotherapy are likely to marginally increase survival, and possibly improve the quality of life for long-term survivors. As the molecular factors underlying childhood brain tumors are better elucidated, molecular-targeted therapy will become a major modality of treatment with the promise of not only increasing the likelihood of survival, but also decreasing treatment-related sequelae.

Special indications in gamma knife surgery

Pilocytic astrocytoma (PA) represent a rare indication for Gamma Knife Surgery. Mostly small remnants after surgical debulking are treated. The prognosis depends on specific variants of biological and clinical criteria. In this regard we differentiated two groups of tumors; the so-called 'typical' tumors with a histological grading of WHO Grade I, no prior fractionated radiotherapy and no cystic component and the so called 'atypical' tumors with either a malignant transformation, previous fractionated radiotherapy and/or cystic components. The outcome after GKS was much more favourable for typical PA than for atypical. In typical cases a high tumor control with a very low risk of side effects can be achieved.