[Value of 123I-MIBG scanning, neuron-specific enolase and serum ferritin in the diagnosis and follow-up of patients with neuroblastoma]. / Valor del rastreo con 123I-MIBG, enolasa neuronal específica y ferritina sérica en el diagnóstico y seguimiento de pacientes con neuroblastoma.

INTRODUCTION: The neuroblastoma (NB) is one of the most common pediatric malignant neoplasms. The most commonly used tumor markers in the diagnosis and follow-up of this tumor are the serum neuron-specific enolase (NSE), ferritin and lactic dehydrogenase and urinary vanillymandelic and homovanillic acid. The common imaging modalities are CT, MRI and 123I or 131I-meta-iodobenzylguanidine scintigraphy. AIM: The aim of this study is to assess the value of 123I-meta-iodobenzylguanidine (MIBG) scintigraphy and serum determinations of NSE and ferritin in the diagnosis and evolution of NB patients. MATERIAL AND METHODS: 20 patients (8 female, 12 male) whose ages ranged from 2 months to 9 years with a mean age of 2.64 years diagnosed of NB. 47 123I-MIBG scans, 47 NSE determinations and 47 ferritin ones were selected. RESULTS: At the time of diagnosis, 100% of the 123I-MIBG scans were positive. 65% of NSE determinations presented clearly pathological levels and 15% were very near to the cut-off point. Only 45% of the ferritin levels were increased. The differences between the lesions visible by 123I-MIBG scanning before and 3 months after treatment as well as NSE and ferritin levels were studied. When the Student's T test was applied, we found statistically significant pre and post-treatment differences in 123I-MIBG scanning and NSE. In the case of ferritin, there was no statistical significance in spite of the decrease in the values. The direct correlation and Spearman correlation between laboratory data and 123I-MIBG scanning as well as correlation between NSE and ferritin were also studied. There was a good correlation between 123I-MIBG and NSE and between NSE and ferritin. We have also studied the data in 7 relapses. CONCLUSIONS: 123I-MIBG scintigraphy and serum determination of NSE are two successful diagnostic tools for the diagnosis and evolution of NB patients.

Genetics of retinoblastoma: a study.

We have analyzed 43 families with either familial retinoblastoma (RB) (four kindreds), bilateral sporadic RB (10 individuals), or unilateral sporadic RB (29 individuals). Genetic studies focused on karyotype analysis, loss of heterozygosity of intragenic polymorphisms, and search for point mutations. We have been able to identify the genetic defect underlying the disease in eight cases. Deletions have been found in three patients with sporadic RB, two bilateral in one of which karyotyping had previously detected an interstitial deletion of chromosome 13 affecting (q13-q31) and one unilateral. Five different point mutations were responsible for three cases of bilateral sporadic RB, one case of bilateral sporadic RB, and one case of bilateral familial RB. The low frequency of constitutional mutations found in our study has led us to review and evaluate the possibilities and limitations of the present genetic analyses on RB and to access the different factors influencing the detection of mutations causing the disease, because genetic counseling is mainly based on mutation identification.