FDG PET and evaluation of posttherapeutic residual tumors in pediatric oncology: preliminary experience.
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.
André
Nicolas
N
Service d'oncologie pédiatrique, Hôpital pour Enfants de La Timone, Marseille, France. nicolas.andre@ap-hm.fr
Fabre
Alexandre
A
Colavolpe
Cécile
C
Jacob
Thierry
T
Gaudart
Jean
J
Coze
Carole
C
Paris
Marie
M
Gentet
Jean Claude
JC
Guedj
Eric
E
Michel
Gérard
G
Mundler
Olivier
O
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
D019788:Fluorodeoxyglucose F18