central nervous system ( cns ) tumors has accounted for approximately 20 - 25% of all pediatric malignancies . cns tumors were the most common solid malignancies in children [ 1 , 2 ] . among the pediatric primary brain tumors , low - grade astrocytoma tumors have comprised approximately one third of all cases . in comparison with adults , high - grade gliomas were less common in children , and then have more frequently observed in the brainstem region [ 3 , 4 ] . treatment modalities which have included surgery , followed by observation , and chemotherapy or radiotherapy , depending on histological characteristics , the extent of tumor resection , and its site [ 5 - 9 ] . prognosis and type of treatment have differed among the children and adults with primary brain tumors . several studies have shown that the grade and extent of tumor resection were the main independent factors that have been affecting the prognosis of glial tumors . other influential factors were the patient s age , the amount of tumor resection and tumor location [ 10 - 12 ] . this study has conducted to reveal the characteristics of pediatric non - brain stem astrocytoma including clinicopathologic behavior , treatment outcomes , and prognostic factors . children with non - brain stem astrocytoma referred to radiation oncology department of omid hospital of mashhad have included in this retrospective study , between the years 2000 - 2010 . the patients who have met the following criteria have included in the study : 1 ) age 16 yrs , 2 ) pathologically confirmed astrocytoma , and 3 ) patients with tumor in non - brain stem region , confirmed by imaging . the exclusion criteria were as follows : 1 ) unavailable pathological report , and 2 ) incomplete medical records . statistical analysis 
  data have analyzed using spss version 16 , and descriptive and analytical methods have utilized . for survival analysis , kaplan - meier method has used , and overall survival has calculated from the time of diagnosis until the time of death to any cause or the last visit . log - rank test has performed to compare survival curves between the groups , and cox - regression test has used for multivariate analysis . of 167 patients with primary brain tumor , 87 cases with the median age of 10 yrs ( range : 2 - 15 yrs ) and male / female ratio of 43/44 had pathologically confirmed non - brain stem astrocytoma ( table 1 ) . tumor grades have illustrated in table 2 . as compared with high - grade cases , low - grade non - brainstem astrocytoma were more common among the younger ages ; 34 ( 63% ) and 8 ( 24.2% ) of low- and high - grade patients were younger than 10 years ( p<0.01 ) , respectively . in comparison with high- grade cases , low - grade astrocytomas have more frequently observed in the infratentorial region ( 15.2% vs. 59.3% , p < 0.001 ) ( table 3 ) . eight ( 9.2% ) cases had a history of epilepsy , and 34 ( 39% ) individuals complained of focal neurological symptoms , with paresis and plegia in 21 ( 24.1% ) and 13 ( 14.9% ) subjects , respectively . in addition , 69 ( 79.3% ) cases were ambulatory at the time of referral . gross total / near - total resection has performed on 58 ( 66.6% ) patients , while 29 ( 33.3% ) cases have only undergone biopsy . patients with low - grade tumors ( grade i , ii ) have undergone subtotal or near - total resection more frequently compared to patients with high - grade tumors ( 75.9% vs. 48.5% , p=0.003 ) . as shown in table 4 , neurologic deficits were significantly more common in children with high - grade tumors ( p<0.001 ) . the intended radiotherapy protocol has completed in 77 ( 88.5% ) subjects . the number of cases who could complete the treatment has slightly higher in patients with low - grade tumors compared to those with high - grade tumors ( 90.6% vs. 85.3% , p=0.47 ) . patients with completed treatment and low - grade astrocytoma have undergone radiotherapy with a median dose of 54 gy ( range : 45 - 57.5 gy ) and those with high - grade tumors have received a median dose of 57 gy ( range : 50 - 60 gy ) . evaluation of survival curves and potential prognostic factors 
  the median follow - up time for patients with low - grade and high - grade astrocytoma was 38 months ( range : 6 - 110 months ) and 16 months ( range : 4 - 100 months ) , respectively . we have recorded 28 deaths during the follow - ups , which were significantly higher in cases with high - grade tumors ; all deaths were tumor - related . there was a significant difference in overall survival curves between different tumor grades ( table 5 , figure 1 ) . group , tumor grade ( grade i vs. grade ii ) , performance status ( ambulatory vs. non - ambulatory ) and surgical resection ( gross total / near - total resection vs. biopsy ) were significant predictors of survival in univariate evaluation . however , in multivariate analysis , only surgical resection and performance status have remained as independent prognostic factors ( table 6 ) . likewise , in the group of high - grade astrocytoma , surgical resection and performance status were significant prognostic factors in both univariate and multivariate analysis ; but , tumor grade ( grade iii vs. grade iv ) was only effective for survival in the univariate assessment ( table 7 ) . according to the results of the present study , glial tumors were the most common primary brain tumors in our patients . likewise , makino k. et al . in a population - based epidemiological study in japan have shown that among 210 children ( younger than 15 years ) with primary brain tumor , astrocytoma was the most common pathology ( 35.7% ) , with a boy to girl ratio of 1.3 . compatible results have obtained in india by jain et al .   and in nigeria by uche et al . . however , the epidemiological profile might be somehow different in other regions of the world . for example , a retrospective hospital - based study in morocco by karkouri et al has shown that medulloblastoma , has been followed by astrocytoma , has diagnosed as the most common brain tumor ( 34.5% ) among children since the birth until the age of 14 . as compatible with previous surveys [ 3 - 6 ] , our study has shown that pediatric non - brain stem astrocytomas were usually low - grade tumors ; also , glioblastoma multiform has less frequently observed among the children in comparison with adults . moreover , compared to adults , pediatric astrocytomas have more commonly located in the infratentorial region ; gender distribution was almost equal in our study . previous trials have revealed tumor grade as a significant prognostic factor in pediatric children with astrocytoma [ 10 - 11 ] . in our study , cases with grade - i astrocytoma ( pilocytic astrocytoma ) had a very favourable outcome , and only 1 out of 20 patients ( 5% ) experienced failure . patients with grade - iv astrocytoma had a very dire prognosis , and all tumors have located in the supratentorial compartment . a plenty of these tumors have associated with significant neurological deficits which have reflected the aggressive nature of the tumor . surgical resection was not optimal in a significant number of high - grade cases , especially for those with grade - iv tumors . children with high - grade astrocytoma have even shown much poor prognosis in comparison with adults , with the same pathology , which might root in biological differences [ 8 , 15 ] . as similar to the present study , the extent of resection , and the effect of neurological deficit on the outcome have been indicated in other trials [ 5 - 7 ] . hales et al . in a study on 63 children with high - grade astrocytoma , whose have managed at john hopkins hospital ( in years 1997 - 2004 ) , has shown that performance status < 80% , resection less than gross total , bilaterally , parietal lobe location and radiation dose < 50 gy have associated with inferior survival . a review of 6,212 cases with pediatric glioma by qaddoumi et al . revealed tumor grade as the most important prognostic factor in all age groups ; although , the extent of resection was the most significant predictor of survival for the youngest ages . the analysis of his study has indicated that inferior survival in younger children with low - grade gliomas might be related to receiving lower radiation doses ; and it might also be related to lower probability for undergoing gross total resection . tumor grade was the most important prognostic factor in children with non - brainstem astrocytoma , which has signified precise pathological diagnosis . for patients with low - grade astrocytoma , achieving optimal surgical resection the final treatment results for high - grade astrocytoma , especially grade iv , were not satisfactory . however , performing gross total resection in high - grade cases could improve clinical outcomes in these patients . tumor grade was the most important prognostic factor in children with non - brainstem astrocytoma , which has signified precise pathological diagnosis . for patients with low - grade astrocytoma , achieving optimal surgical resection the final treatment results for high - grade astrocytoma , especially grade iv , were not satisfactory . however , performing gross total resection in high - grade cases could improve clinical outcomes in these patients .
backgroundcentral nervous system ( cns ) tumors have accounted for approximately one fourth of all pediatric malignancies . 
 cns tumors have been the most common solid malignancies among the children . in this study , we have evaluated survival and prognostic factors in children with non - brain stem astrocytoma.methodschildren with non - brain stem astrocytoma , referring to radiation oncology centers of ghaem and omid hospitals of mashhad , have included in this retrospective study , in years 2000 - 2010 . 
 patients demographic data , past medical history , clinical symptoms , extent of tumor resection and treatment modality have recorded . 
 disease - free survival and overall survival have measured using kaplan - meier method.resultswe studied 87 patients with male to female ratio of 44/43 ( 1.02 ) , and median age of 10 yrs ( range : 2 - 15 yrs ) . 
 tumor grade distribution was as follows : grade i : 20 ( 23% ) subjects ; grade ii : 34 ( 39.1% ) subjects ; grade iii : 20 ( 23% ) subjects ; and grade iv : 13 ( 14.9% ) subjects . 
 the median follow - up duration was 38 months ( 6 to 110 ) , and 16 months ( 4 to 100 ) for patients with low- and high - grade tumors . 
 the 2-year survival rates in grades i - iv were 100% , 84.7% , 60% and 10.8% , respectively . 
 tumor resection less than gross total and non - ambulation have associated with a significantly inferior survival in both groups multivariate analysis , with high- and low - grade tumors.conclusionfor all the cases of the pediatric non - brainstem astrocytoma , tumor grade had dramatic influences on their survival . performing 
 gross total resection was crucial for achieving favorable outcomes in both low - grade and high - grade cases . 
 moreover , according to the results , having major motor deficits has associated with lower survival .