RADIOIODINATED METAIODOBENZYLGUANIDINE IN NEUROBLASTOMA - INFLUENCE OF HIGH-DOSE ON TUMOR SITE DETECTION

For more than a decade radioiodinated metaiodobenzylguanidine (mIBG) h as been commonly used for neuroblastoma imaging. The accuracy of this scintigraphic method in detecting both primary and secondary tumour si tes is crucial when evaluating the extent of disease. The aim of our s tudy was to assess the impact of high-activity mIBG scintigraphy on ne uroblastoma staging. Eighteen scans (TS) were obtained in 15 children after a therapeutic dose of iodine-131 mIBG and compared to diagnostic mIBG scans (DS) (in eight cases with I-131-mIBG and in ten cases with I-121-mIBG). The superiority of TS over DS was confirmed by the overa ll results: a total of 220 lesions were disclosed with TS and 171 with DS. However, in only one case did the TS findings, namely skeletal in volvement not evidenced on corresponding DS, have an impact on clinica l staging. In contrast, neither TS nor DS detected proven bone involve ment in four patients. The dose-related sensitivity of mIBG scintigrap hy in detecting neuroblastoma tumour sites was confirmed. The ultimate impact of high-dose scans on neuroblastoma management, however, seems limited.