99mTc-HYNIC octreotide in neuroblastoma

Disease status assessment of neuroblastoma patients requires computed tomography (or magnetic resonance imaging), bone scan, metaiodobenzylguanidine (MIBG) scan, bone marrow tests, and urine catecholamine measurements. There is no clinical experience concerning the evaluation of these patients by means of technetium-99m (Tc-99m)-somatostatin analog scintigraphy. Furthermore, these radiopharmaceuticals are promising imaging agents owing to their lower cost, availability, dosimetry, and ease of preparation. An 8-year-old boy already diagnosed with stage-IV neuroblastoma received chemotherapy. In the follow-up, after obtaining the parents' informed consent, iodine-131 (I-131)-MIBG and Tc-99m-6-hydrazinopyridine-3-carboxylic acid (HYNIC)-octreotide scans were done on separate days to evaluate tumor extension. Even as the I-131-MIBG scan showed mild diffuse uptake in the projection of both lung hili, the Tc-99m-HYNIC-octreotide scan showed multiple axial and appendicular bone uptakes and paravertebral, abdominal, mediastinal, and supraclavicular ganglionar uptakes. The Tc-99m-HYNIC-octreotide showed much more lesion extension than the I-131-MIBG. Therefore, Tc-99m-HYNIC-octreotide may be a promising radiopharmaceutical for the evaluation of neuroblastoma patients. This finding justifies the preliminary evaluation of this tracer in the context of a clinical trial.