Comparison of MIBG and pentetreotide scintigraphy in children with neuroblastoma. Is the expression of somatostatin receptors a prognostic factor?

Background: Neuroblastoma (NB) is the fourth most common pediatric malignancy and recent reports suggest a prognostic role of somatostatin receptor scintigraphy (SRS) in this disease. Materials and Methods: Twenty two patients (pts, mean age 43.9 months) with NE were investigated by I-123-MIBG and SRS (In-111-pentetreotide). Twenty-seven comparative scans were evaluated and compared for catecholamin excretion, Ultrasound, CT and MRI data. The patients were then. divided into three groups. I: patients with manifest disease, II: patients with relapse or. minimal disease and III: patients with no evidence of disease. Results: MIBG and SRS scans were concordant in 85% (12 true positive, 7 true negative, 4 false negative). In 4 pts only rite MIBG scan was positive. In 9 pts with stage I-III disease or complete remission no relapse was recorded during 19.8 months. In 4 out of 5 pts who died SRS failed to localize the tumor sites but three MIBG scans was positive. Five out of 6 pts with a relapse free interval of 7.9 months had positive SRS and MIBG scans. Conclusions: in NE SRS can be applied as a specific imaging modality. However in some pts SRS failed due to the lack of receptor expression. Somatostatin receptor expression seems to be related with a more favourable clinical outcome.