Nuclear medicine therapy of neuroblastoma

Specific targeting of radionuclides to neuroblastoma, a mural crest tumour occurring predominantly in young children and associated with a relatively poor prognosis, may be achieved via the metabolic route (MIBG), receptor bi nding (peptides) or immunological approach (antibodies), The clinical role of I-131-MIBG therapy and radioimmunotherapy in neuroblastoma is discussed. in recurrent or progressive metastatic disease after conventional treatmen t modalities have failed, I-131-MIBG therapy, with an overall objective res ponse rate of 35%, is probably the best palliative treatment, as the invasi veness and toxicity of this therapy compare favourably with that of chemoth erapy, immunotherapy and external beam radiotherapy. in patients presenting with inoperable stage III and TV neuroblastoma, 131I-MIBG therapy at diagn osis is at least as effective as combination chemotherapy but is associated with much less toxicity. in patients with recurrent disease I-131-MIBG the rapy in combination with hyperbaric oxygen therapy proved feasible and enco uraging effects on survival have been observed Attempts to intensify the tr eatment in relapsed patients by combination of 131I-MIBG therapy with high dose chemotherapy and/or total body irradiation have met with considerable toxicity. Developments in MIBG therapy alining at improving the therapeutic index are mentioned. Early results of radioimmunotherapy using I-131-UJ13A Or I-131-3F8 monoclonal antibodies have shown moderate objective response and considerable side effects in patients with stage IV neuroblastoma, who had relapsed or failed conventional therapy. New developments in radioimmun otherapy of neuroblastoma include the use of chimaeric antibodies, the enha ncement of tumour uptake by modulation of antigen expression or by increasi ng the tumour perfusion/vascularity/permeability, the use of other labels a nd multistep targeting techniques, e.g. using bispecific monoclonal antibod ies.