Is there a role for FDG-PET for the assessment of treatment efficacy in Wilms' tumor? A case report and literature review.
BACKGROUND
The role of FDG-PET in Wilms' tumor has not been well established. The aim of this report is to describe the role of FDG-PET to assess chemotherapy efficacy and to show potential correlations between different Standardized Uptake Values (SUVs) and histopathological features in a patient with persisting metastatic disease.


METHODS
A 3-year-old boy was diagnosed with Wilms' tumor without anaplasia. The patient underwent treatment as according to the AIEOP-TW-2003 protocol, for stage III tumors. Therapy was discontinued with no evidence of disease, yet 9 months later thorax metastases were found. Although second and third line treatments were administered, conventional imaging demonstrated stable disease. Metronomic chemotherapy as well was employed for 44 months and FDG-PET was annually performed basing on responsible local physician choice trying to better describe the disease status. Four months after fourth line treatment was stopped, the patient manifested clinical symptoms; lesions began to increase their metabolic activity inhomogeneously. Therapy was hence restarted and SUVs decreased. Metastasectomies were then performed and histology revealed a correlation between viable disease shown by higher FDG-PET uptake and viable tumor areas.


CONCLUSIONS
Our case discussion demonstrates that FDG-PET is potentially valuable in Wilms' tumor correlating SUV values and histological features of the tumor after chemotherapy. This case suggests that FDG-PET is a valid tool to assess chemotherapy response in relapsed Wilms' tumor even in case of no evidence of significant dimensional changes under conventional imaging.
1Department of Pediatrics, Ospedale Papa Giovanni XXIII, Bergamo, Italy.
M
M
Provenzi
F
F
Saettini
V
V
Conter
D
D
Chinaglia
P
P
Vai
A
A
Bruno
L
L
Cavalleri
C
C
Foglia
E
E
Giraldi
P
P
Collini
F
F
Spreafico
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage*; D002675:Child, Preschool; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011859:Radiography; D019275:Radiopharmaceuticals / Q000008:administration & dosage*; D013997:Time Factors; D009396:Wilms Tumor / Q000000981:diagnostic imaging / Q000517:prevention & control
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18