title: Spontaneous regression of residual low-grade cerebellar pilocytic astrocytomas in children.
abstract: BACKGROUND
  Cerebellar low-grade astrocytomas (CLGAs) of childhood are benign tumours and are usually curable by surgical resection alone or combined with adjuvant radiotherapy.
  
  
  OBJECTIVE
  To undertake a retrospective study of our children with CLGA to determine the optimum schedule for surveillance imaging following initial surgery. In this report we describe the phenomenon of spontaneous regression of residual tumour and discuss its prognostic significance regarding future imaging.
  
  
  METHODS
  A retrospective review was conducted of children treated for histologically proven CLGA at Great Ormond Street Hospital from 1988 to 1998.
  
  
  RESULTS
  Of 83 children with CLGA identified, 13 (15.7%) had incomplete resections. Two children with large residual tumours associated with persistent symptoms underwent additional treatment. Eleven children were followed by surveillance imaging alone for a mean of 6.83 years (range 2-13.25 years). Spontaneous tumour regression was seen in 5 (45.5%) of the 11 children. There were no differences in age, gender, symptomatology, histological grade or Ki-67 fractions between those with spontaneous tumour regression and those with progression. There was a non-significant trend that larger volume residual tumours progressed.
  
  
  CONCLUSIONS
  Residual tumour followed by surveillance imaging may either regress or progress. For children with residual disease we recommend surveillance imaging every 6 months for the first 2 years, every year for years 3, 4 and 5, then every second year if residual tumour is still present 5 years after initial surgery. This would detect not only progressive or recurrent disease, but also spontaneous regression which can occur later than disease progression.
authors.affiliation: Department of Radiology, Great Ormond Street Hospital for Sick Children, London, UK. gunnyr1@gosh.nhs.uk
authors.forename: Roxana S
authors.initials: RS
authors.lastname: Gunny
authors.forename: Richard D
authors.initials: RD
authors.lastname: Hayward
authors.forename: Kim P
authors.initials: KP
authors.lastname: Phipps
authors.forename: Brian N
authors.initials: BN
authors.lastname: Harding
authors.forename: Dawn E
authors.initials: DE
authors.lastname: Saunders
mesh_terms: D000293:Adolescent; D001254:Astrocytoma / Q000473:pathology*; D002528:Cerebellar Neoplasms / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D009365:Neoplasm Regression, Spontaneous / Q000473:pathology*; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012720:Severity of Illness Index; D016896:Treatment Outcome