Comparison of scintigraphy with 123I-MIBG and 99mTc-tectrotyde in patients with tumors of a neurogenic nature

Introduction . Neuroblastoma (NB) is the most common extracranial solid tumor in children; it ranks third in the structure of childhood oncopathology, and in the structure of infant cancer up to 1 year of age, it ranks first. In children over 1 year of age, stages 3–4 are detected in more than 50 % of cases. In 60 % of cases, patients with stage 4 are diagnosed with bone marrow and/or bone involvement. This group of patients has one of the lowest survival rates in oncopediatrics. To carry out primary staging, assess the effectiveness of therapy, monitoring and for theranostic purposes, scintigraphy with 123I-MIBG is most often used. There are also studies demonstrating the diagnostic effectiveness of radionuclide studies of NB with somatostatin analogues, which include 99mTc-tectrotyde. Currently, two diagnostic radiopharmaceutical are registered in the Russian Federation: the “reference” 123I-MIBG, the most commonly used for diagnosing NB, and the potentially useful, but not used 99mTc-tectrotyde. Purpose of the study – to determine the possibility of using 99mTc-tectrotyde as a diagnostic radiopharmaceutical for neurogenic tumors in children and compare the diagnostic capabilities of scintigraphy with 123I-MIBG and 99mTc-tectrotyde. Materials and methods . The study included patients with a morphologically verified diagnosis before treatment: 7 patients diagnosed with NB and 1 with a diagnosis of paraganglioma. All patients underwent two consecutive scintigraphic studies: with 123I-MIBG and with 99mTc-tectrotyde with the minimum possible time interval between them (2–6 days), the sequence did not matter. A quantitative assessment of the accumulation levels of both radiopharmaceuticals was carried out using the SPECT/CT method. Results. Compared with 123I-MIBG, 99mTc-tectrotyde scintigraphy allowed visualization of the primary tumor in 7 out of 8 patients, while all metastases were visible in only 1 out of 3 patients. Conclusion. Our study was the first to compare 123I-MIBG and 99mTc-tectrotyde in the diagnosis of childhood neurogenic tumors before treatment. Scintigraphy with 99mTc-tectrotyde turned out to be applicable for the diagnosis of neurogenic tumors, however, a small sample of patients does not allow us to determine the diagnostic effectiveness and requires further study.