CARATTERIZZAZIONE DI LESIONI DI ORIGINE SCONOSCIUTA SOSPETTE PER
LESIONI MALIGNE NEI PAZIENTI PEDIATRICI: POSSIBILE RUOLO DEL 18F-FDG
PET/CT
A.Cistaro1, , E. Basso2, R. Laudati2, M. Bianchi2, M. Piglione2, S. Lijoi2, A. Linari3, P. Fania1, E. Panighetto1, F. Fagioli2
1. Positron Emission Tomography Center IRMET S.p.A., Turin, Italy
2. Onco-Hematology Department, Regina Margherita Infant Hospital, Turin, Italy
3. Histopathology Departement, Infant Hospital Regina Margherita, Turin, Italy
AIM
The value of PET/CT in paediatric patients has not yet been completely established. The
most noticeable clinical benefit of combined PET/CT is the improvement of lesion
localisation and the ability to apply the fused data set for planning of biopsy and/or local
therapy such as surgery or radiotherapy.
Aim: to asses the role of PET-CT in the metabolic characterisation of lesions of unknown
origin, suspected for malignant disease, in paediatric patients.
MATERIAL AND METHODS
twelve patients (6 M, 6 F), median age 12, with the suspected diagnosis of malignant disease,
underwent FDG-PET/CT. FDG-PET imaging was performed 60 min after iv injection of
18FDG using an hybrid FDG-PET/CT. FDG-PET were interpreted visually
Guided-biopsy was performed, within 2 weeks of FDG-PET, in the pathological focus
showing the higher SUVmax when a malignant disease was suspected on the basis of PETCT exam. On the contrary, patients with negative PET-CT underwent only a clinicalradiological follow-up.
RESULTS
PET-CT was positive in 7 patients. The histological analysis on guided-biopsy performed on
the site with higher metabolic activity has shown: 2 NHL following autoimmune
lymphoproliferative syndrome caused by FAS mutation, 3 primitive NHL and 2 primitive HL.
PET-CT was negative (low metabolically active lesions) in 5 patients: 1 eosinophilic
granuloma, 2 lung aspergillosis, 1 spondilodiscitis, 1 lymphadenitis. In all “negative” patients
clinical-radiological follow-up (at least 6 months after PET-CT) confirmed the absence of
malignant disease.
CONCLUSIONS
PET/CT is a useful tool in the metabolic characterisation of lesions of unknown origin,
suspected for malignant disease in paediatric patients.
It improves lesion localisation
it allows a guided-biopsy, identifyng the more accessible and active sites, thus increasing
diagnostic rate.
It allows to avoid biopsy in patients with a PET-CT negative for disease, with a high
metabolical activity.
The combination of structural and metabolic information improves the accuracy of
diagnosis and has the potential to change managment in a significant number of paediatric
patients.
It remains to be seen whether PET/CT can reduce the number of other studies that are
requested for confirmation or exclusion of malignancy in the presence of equivocal findings.
a
Metabolic characterisation of bone e
tissue lesions.
Finally diagnosis spondilodiscitis.
PET-CT resulted able to indicate the
most active and accessible site guiding
biopsy.
Finally diagnosis LNH.
b
Metabolic characterisation of bone lesion.
Finally diagnosis eosinophilic granuloma. PET/CT exam
allowed to avoid biopsy.
Metabolic characterisation of bone lesion.
Finally diagnosis was lung NHL in ALPS Fas gene mutation.
PET/CT exam allowed to guide biopsy (a) and assess the response
to the treatments (b).
For contact: a.cistaro@irmet.com