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 NB were investigated by 1-123-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 the 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 were positive. Five out of 6 pts with a relapse free interval of 7.9 months had positive SRS and MIBG scans.

Conclusions: in NB 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.