Utilidad del rastreo con 123-I-MIBG en el diagnóstico y seguimiento del neuroblastoma en pacientes pediátricos: resultados preliminares

Abstract

Introduction Neuroblastoma (NB) is the most frequent extracranial solid tumor in children. The localization and staging are essential to establish the treatment and follow up the disease. Conventional imaging methods are CT, MRI, and whole-body 123I-metaiodobenzylguanidine (123I-MIBG) scintigraphy. Objective The main objective of this study was to evaluate the usefulness of 123I-MIBG scintigraphy in the diagnosis and follow-up of pediatric patients. A secondary objective was to compare the diagnostic validity of 123I-MIBG scintigraphy and CT in the initial diagnosis. Material and methods Thirty patients with suspected neuroblastoma were studied (17 males and 13 females aged between 0 months and 11 years; mean age of 2.17 years); 45 123I-MIBG scans and 30 CT scans were selected for analysis. Results For the initial diagnosis, a sensitivity of 92.31%, specificity of 100%, PPV of 100%, and NPV of 66.67% were obtained with MIBG versus a sensitivity of 88.46%, specificity of 20%, PPV of 85.19%, and NPV of 25% with CT. False negatives were highly similar between the techniques, but there were more false positives with CT. Evaluation of the usefulness of MIBG to detect metastases showed that 38.46% of patients (10/26) had distant lesions in addition to the primary tumor. The number of lesions observed on MIBG scans did not significantly differ (p> 0.05, Wilcoxon test) between the diagnosis and three months after the last treatment. An excellent correlation (Kappa value of 0.8538) was found between MIBG results and clinical outcomes. Conclusion 123I-MIBG offers high sensitivity and specificity in the initial diagnosis of pediatric patients with neuroblastoma, clearly superior to those obtained with CT, and it has demonstrated its usefulness as a diagnostic and follow-up tool.