title: FDG PET and evaluation of posttherapeutic residual tumors in pediatric oncology: preliminary experience.
abstract: BACKGROUND
  Residual masses are an important problem in oncology. The determination of their nature (fibrosis or active tumor) is crucial. The place of 18F-fluorodeoxyglucose -positron emitting tomography (PET) as a new imaging device remains to be determined in this context.
  
  
  OBJECTIVE
  To evaluate the place of 18F-fluorodeoxyglucose -PET in the prediction of the nature of residual masses in children with solid tumors.
  
  
  METHODS
  Between January 2004 and January 2006, 238 PETs were performed in children followed up in the pediatric oncology and hematology departments. This was a monocentric retrospective review of the medical files of 18 children, in whom the main objective of the PET was to evaluate a residual mass. The sex ratio was 1/5; the median age 100 months (range, 34 to 180 mo). The underlying diseases were Hodgkin disease (n=5), lymphomas (n=5), osteosarcomas (n=3), rhabdomyosarcomas (n=2), and others (n=3). The final diagnostic (remission or persistent disease) was given by follow-up (median, 18 mo; range, 18 to 40), together with clinical, radiologic, and biopsy (in 6 cases) data.
  
  
  RESULTS
  PET was negative in 13 cases and positive in 5, among them 4 patients relapsed. Among the 13 negative PETs, there was 1 relapse and 12 remissions. The respective value of PET sensibility and specificity were 0.8 and 0.92, respectively. Positive and negative predictive values were 0.8 and 0.92, respectively.
  
  
  CONCLUSIONS
  On the basis of these preliminary results, PET seems to be an interesting tool to assess the nature of posttherapeutic residual masses in children, regardless of the underlying malignancy. Its role needs to be confirmed and further explored by multicentric studies tailored according to the underlying disease.
authors.affiliation: Service d'oncologie pédiatrique, Hôpital pour Enfants de La Timone, Marseille, France. nicolas.andre@ap-hm.fr
authors.forename: Nicolas
authors.initials: N
authors.lastname: André
authors.forename: Alexandre
authors.initials: A
authors.lastname: Fabre
authors.forename: Cécile
authors.initials: C
authors.lastname: Colavolpe
authors.forename: Thierry
authors.initials: T
authors.lastname: Jacob
authors.forename: Jean
authors.initials: J
authors.lastname: Gaudart
authors.forename: Carole
authors.initials: C
authors.lastname: Coze
authors.forename: Marie
authors.initials: M
authors.lastname: Paris
authors.forename: Jean Claude
authors.initials: JC
authors.lastname: Gentet
authors.forename: Eric
authors.initials: E
authors.lastname: Guedj
authors.forename: Gérard
authors.initials: G
authors.lastname: Michel
authors.forename: Olivier
authors.initials: O
authors.lastname: Mundler
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D018365:Neoplasm, Residual / Q000000981:diagnostic imaging* / Q000473:pathology; D049268:Positron-Emission Tomography; D012008:Recurrence; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18