***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: PURPOSE To determine clinical characteristics and response to treatment for children with supratentorial primitive neuroectodermal tumors ( S-PNETs ) . PATIENTS AND METHODS After surgery and staging , 55 patients aged 1.5 to 19.3 years with S-PNETs were r and omized to receive craniospinal radiotherapy ( RT ) followed by eight cycles of 1-(2-chloro-ethyl)-3-cyclohexylnitrosourea ( CCNU ) , vincristine ( VCR ) , and prednisone ( st and ard treatment ) or two cycles of 8-in-1 chemotherapy followed by RT and then eight additional cycles of 8-in-1 . RESULTS Three-year Kaplan-Meier estimates ( estimate + /- SE ) of survival and progression-free survival ( PFS ) rates for patients with confirmed diagnoses of S-PNET were 57 % + /- 8 % and 45 % + /- 8 % , respectively ; survival and PFS rates for children with PNETs located in the pineal region were 73 % + /- 12 % and 61 % + /- 13 % , respectively , and were significantly different from the other S-PNETs ( P < .03 ) . The 8-in-1 arm had greater toxicity than the st and ard-treatment arm . Distributions of PFS between the two treatment groups were not significantly different ( P > .5 ) . Other univariate prognostic factors that influenced PFS included metastasis ( M ) stage ( P < .03 : M0 50 % + /- 9 % v M1 - 4 0 % ) and age ( P < .02 : 1.5 to 2 years 25 % + /- 13 % v > or = 3 years 53 % + /- 9 % ) . CONCLUSION In this first r and omized treatment trial for S-PNETs in children , no significant differences were detected between the two treatment groups . M0 and pineal site of involvement were independent predictors of a better outcome . However , survival was better than previously reported Autologous hematopoietic stem cell transplant ( AHSCT ) has been advocated as a form of salvage therapy for children with high-risk or relapsed brain tumors but only limited data are available currently . We report the outcomes of  pediatric brain tumors treated with AHSCT in a quaternary referral center in Hong Kong over 10 years ( June 1996–May 2006 ) . Thirteen patients with medulloblastoma ( n = 9 ) , cerebral primitive neuroectodermal tumor ( n = 1 ) , ependymoma ( n = 1 ) , germ cell tumor ( n = 1 ) and cerebellar rhabdoid ( n = 1 ) were transplanted because of tumor residual ( n = 1 ) or recurrence ( n = 12 ) . Uniform upfront treatment protocol s were adopted according to specific tumor types . Prior to AHSCT , 8 patients ( 61.5 % ) achieved complete remission and 5 ( 38.5 % ) were in partial remission . Conditioning employed thiotepa 300 mg/m2 , etoposide 250 mg/m2 and carboplatin 500 mg/m2 daily for 3 days . Toxicity included mucositis and neutropenic fever in all patients , grade 4 hepatic toxicity in 4 patients ( including hepatic veno-occlusive disease in 2 patients ) and grade 4 renal toxicity in 1 patient . The 5-year event-free survival was 53.9 % . Five patients died of disease recurrence or progression 8–21 months after transplant with a median disease-free period of 8 months post-transplant . One died of transplant-related complications in the early post-transplant period . Seven survived for a median of 5.4 years ( maximum follow-up of 9.8 years ) , with six having Lansky-Karnofsky performance score above 80 . All survivors had complete remission before transplant though 2 had leptomeningeal spread . We conclude that AHSCT can achieve long-term survival in children with recurrent brain tumor . However , those with macroscopic residual tumor before transplant can not be salvaged Current treatment for high risk and recurrent medulloblastoma ( MB ) and supratentorial primitive neuroectodermal tumors ( stPNET ) has a very poor prognosis in children .  High dose chemotherapy ( HDCT ) and autologous stem cell rescue have improved survival rates . We present 19 patients ( thirteen classified in the high risk group and six patients with recurrent disease ) that received HDCT and autologous stem cell rescue .  In the high risk group [ Med Pediatr Oncol 38 ( 2002 ) 83 ] , all patients underwent neurosurgical debulking . St and ard chemotherapy was prescribed in 10 patients . Radiotherapy was given to 4 patients ( all older than 4 years old ) . In the recurrence disease group [ Childs Nerv Syst 15 ( 1999 ) 498 ] , five patients underwent surgery . Radiotherapy was given to those who were not previously irradiated . The HDCT in twelve patients consisted of busulfan 4 mg/kg/day , orally over 4 days in 6-hourly divided doses and melphalan at a dose of 140 mg/m2/day by intravenous infusion over 5 min on day −1 . Three patients additionally received thiotepa 250 mg/m2/day intravenously over 2 days and four patients additionally received topotecan 2 mg/m2/day over 5 days by intravenous infusion over 30 min . The other seven patients received busulfan and thiotepa at the same doses . Patient ’s stem cells were mobilized with granulocyte colony-stimulating factor at a dose of 12 μg/kg twice daily subcutaneously for four consecutive days . Cryopreserved peripheral blood progenitor cells were re-infused 48 h after completion of chemotherapy . With a median follow-up of 34 months ( range 5–93 ) eight complete responses and one partial response were observed . Three patients died of treatment-related toxicities ( 15 % ) . The 2 year event-free survival was 37.67 ± 14 % in all patients and 57 ± 15 % for the high risk group . Therefore we conclude that HDCT may improve survival rates in patients with high risk/recurrent MB and stPNET despite treatment toxicity PURPOSE This study evaluates the outcome of myeloablative chemotherapy and autologous bone marrow rescue ( ABMR ) with or without radiotherapy in children younger than 6 years of age with recurrent malignant brain tumors who had not previously been exposed to conventional fractionated external-beam irradiation . PATIENTS AND METHODS Patients underwent surgery and /or conventional chemotherapy at the time of recurrence to achieve minimal residual disease ( two of these patients also underwent local single-fraction gamma-knife radiosurgery ) . Myeloablative chemotherapy was then administered with carboplatin , thiotepa , and etoposide ( 16 patients ) , thiotepa and etoposide ( three patients ) , or thiotepa , etoposide , and carmustine ( BCNU ; one patient ) . Autologous bone marrow was re-infused 72 hours after chemotherapy . Twelve patients received external-beam irradiation after recovery from ABMR . RESULTS Twenty patients with recurrent brain tumors aged 0.7 to 5.9 years ( median , 2.9 years ) at ABMR were evaluated . Two patients died of toxicity related to myeloablative therapy . Eight patients died of progressive disease . Ten of 20 ( 50 % ) patients ( primitive neuroectodermal tumor (PNET)/medulloblastoma , three patients ; cerebral PNET , three patients ; glioblastoma multiforme , two patients ; anaplastic astrocytoma , one patient ; pineal PNET , one patient ) are alive and disease free at a median of 37.9 months ( range , 9.7 to 98.2 months ) from ABMR ( 3-year overall survival [ OS ] rate of 43 % + /- 13 % and event-free survival [ EFS ] rate of 47 % + /- 14 % ] . Seven of these 10 patients also received irradiation post-ABMR . CONCLUSION Myeloablative chemotherapy with ABMR followed by additional external-beam irradiation appears to be an effective retrieval therapy for some young children with recurrent malignant brain tumors BACKGROUND Single or t and em double high-dose chemotherapy ( HDCT ) was used to treat children with newly diagnosed high-risk or relapsed medulloblastoma and supratentorial primitive neuroectodermal tumor ( MB/sPNET ) in order to defer or avoid radiotherapy in young children . PROCEDURE Thirty-seven HDCTs were given to 25 children with newly diagnosed high-risk or relapsed MB/sPNET .  T and em double HDCT was used for 12 of 15 patients initially intended to receive double HDCT . RESULTS Three-year EFS ( + /-SE ) in 6 newly diagnosed high-risk ( > 3 years old ) , 8 newly diagnosed ( <3 years old ) , and 11 relapsed MB/sPNET was 83.3 + /- 15.2 % , 62.5 + /- 20.5 % , and 29.1 + /- 15.7 % , respectively . Three-year EFS for patients in CR or PR and in less than PR at first HDCT was 67.4 + /- 11.0 % and 16.7 + /- 15.2 % , respectively ( P = 0.001 ) . Three-year EFS in patients initially intended to receive double HDCT and single HDCT was 66.0 + /- 12.4 % and 40.0 + /- 15.5 % , respectively . For 19 patients in CR or PR at first HDCT , 3-year EFS was 88.9 + /- 10.5 % in t and em double HDCT group , and 44.4 + /- 16.6 % in single HDCT group , respectively ( P = 0.037 ) . Although four treatment-related mortalities ( TRMs ) occurred during 25 first HDCTs , no TRM occurred during 12 second HDCTs . In four of eight young children , craniospinal radiotherapy was successfully withheld without subsequent relapse . CONCLUSIONS High-dose chemotherapy may improve the survival of children with newly diagnosed high-risk MB/sPNET , and , to some extent , the survival of those with relapsed MB/sPNET . Further study is necessary to eluci date the efficacy of t and em double HDCT PURPOSE To describe the biologic and clinical features of children with primitive neuroectodermal tumors ( PNETs ) arising in the pineal region ( pineoblastomas ) and evaluate prospect ively the efficacy of radiation therapy ( RT ) and /or chemotherapy . PATIENTS AND METHODS Between 1986 and 1992 , 25 children with PNETs of the pineal region were treated as part of a Childrens Cancer Group study . Eight infants less than 18 months of age were nonr and omly treated with eight-drugs-in-1-day chemotherapy without RT . The remaining 17 patients were treated with craniospinal RT and r  and omized to receive either vincristine , lomustine ( CCNU ) , and prednisone or the eight-drugs-in-1-day regimen . RESULTS Of 24 completely staged patients , 20 ( 83 % ) had localized disease at diagnosis . All infants developed progressive disease a median of 4 months from the start of treatment . Of the 17 older patients treated with RT and chemotherapy , the Kaplan-Meier estimate of progression-free survival ( PFS ) at 3 years is 61 % + /- 13 % . This is superior to the PFS of children with other supratentorial PNETs ( P = .026 ) . Following RT , 12 of 17 patients ( 70.6 % ) had a residual pineal region mass , which persisted for as long as 5 years before resolving ; only four subsequently developed progressive disease . CONCLUSION ( 1 ) Eight-in-1 chemotherapy without RT appears to be ineffective therapy for young children with PNETs of the pineal region . ( 2 ) For children more than 18 months of age at diagnosis treated with craniospinal RT and chemotherapy , the PFS is superior to that of children with other supratentorial PNETs . ( 3 ) A residual enhancing mass following RT is not predictive of treatment failure BACKGROUND Children with newly diagnosed supratentorial primitive neuroectodermal tumors ( sPNET ) have poor outcomes compared to medulloblastoma patients , despite similar treatments . In an effort to improve overall survival ( OS ) and event-free survival ( EFS ) and to decrease radiation exposure , the Head Start ( HS ) protocol s treated children with newly diagnosed sPNET utilizing  intensified induction chemotherapy ( ICHT ) followed by consolidation with myeloablative chemotherapy and autologous hematopoietic cell rescue ( AuHCR ) . PROCEDURES Between 1991 and 2002 , 43 children with sPNET were prospect ively treated on two serial studies ( HS I and II ) . After maximal safe surgical resection , patients on HS I and patients with localized disease on HS II were treated with five cycles of ICHT ( vincristine , cisplatin , cyclophosphamide , and etoposide ) . Patients 
    Output:
    
Cox regression analysis revealed pineal location as the only independent adverse prognostic factor .
In conclusion high dose chemotherapy with HSCR might lead to survival primarily in younger children with relapsed sPNET even in the absence of concomitant use of radiotherapy , whereas the outcome in older children and /or in pineal location is extremely poor with this modality