FDG PET and evaluation of posttherapeutic residual tumors in pediatric oncology: preliminary experience.

INTRODUCTION: 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. OBJECTIVES: To evaluate the place of 18F-fluorodeoxyglucose -PET in the prediction of the nature of residual masses in children with solid tumors. PATIENTS AND 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. CONCLUSION: 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.

Sonographic diagnosis of a common pancreaticobiliary channel in children.

BACKGROUND: A common pancreaticobiliary channel is a very rare condition, but its diagnosis is of paramount importance since it can lead to complications that can be prevented. OBJECTIVE: To illustrate the sonographic diagnosis of a common pancreaticobiliary channel in children referred for abdominal pain or jaundice. MATERIALS AND METHODS: Four children were diagnosed by ultrasonography and the diagnosis was subsequently confirmed by MRI. RESULTS: Sonography demonstrated a pancreaticobiliary junction located in the pancreatic head above the sphincter of Oddi. This rare congenital anomaly was confirmed in all patients by MRI. CONCLUSION: A common pancreaticobiliary channel can be diagnosed by sonography. Nevertheless, our experience is limited, and although sonography can provide an alert and can assist management, it cannot yet replace MRI.