Predictive value of FDG PET/CT in pediatric Neuroblastoma patients

Document Type : Original Paper, Oncology

Author

Lecturer Of nuclear medicine, National Cancer Institute, Cairo University.

Abstract

Purpose: To explore the prognostic
value of F-18 FDG PET/CT in
neuroblastoma patients. Materials
and method: comparative study
with 63 pathologically proved NB
patients with dominating high risk
category (~65.1 %) who underwent F-
18 FDG PET/CT using standard
technique for purpose of initial, posttherapy or follow up assessment.
Clinico-pathological, radiological and
follow up data were also
collected.Results:FDG uptake level
was expressed in terms of maximum
standardized uptake of the primary
lesion against the maximum
standardized uptake of the reference
liver activity and maximum
standardized uptake of the primary
lesion stands alone where ROC curves
marked cut off values of 1.95 & 2.05
respectively (both are almost double
the reference hepatic activity). The
marked cut-off values were tested in
respect to the established clinicopathological features and the disease
outcome. we found significant
relationship between the Shimada
classification and FDG uptake level
,using 2.05 (cut-off value of the max
SUV of the primary lesion), where
88.9% of those with favorable
histology exhibit low FDG tumor
uptake , while on the contrary 51.9 %


of those with unfavorable histology
showed high FDG uptake level
exceeding the cut-off value 2.05.The
rest of correlation of both cut-off
values with the other clinicopathological features showed
prevalence of increased primary tumor
uptake of FDG (almost equal to or
above double the reference hepatic
activity) among those with less
favorable clinico-pathological features
yet was not statistically significant.As
a trial to quantitatively evaluate the
impact of variable patterns of tracer
accumulation on overall survival
using the suggested cut off values.
Our results revealed higher risk for
lower 2 years overall survival with
increased tumor accumulation of FDG
which was statistically significant
when using max SUV of the primary/
max SUV of the hepatic activity cutoff value (1.95) (p-value=0.05) and a
trend was seen with max SUV of the
primary(p-alue=0.07).
CONCLUSION: PET-CT seems a valuable prognostic indicator where higher tracer accumulation of F-18 FDG seems to be linked to unfavorable histology and lower survival.


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