¹³¹I-MIBG as first-line. ¹³¹I-MIBG treatment can be given upfront to reduce large and bulky tumors in order to enable surgery to remove the primary tumor. This induction therapy is followed by chemotherapy, ablative chemotherapy and autologus bone marrow infusion. In 54 patients with stage III or IV objective response was observed in 82% after a first dosage of 7.4 GBq followed by 3.7 GBq every four weeks (range 2-5 cycles). Thrombocytopenia was seen in 37%. The condition of the patients improved dramatically, as is expressed by relief of pain within 24 to 48 after first dose, and weight gain of 3-11% (11). Five-year-survival after completion of treatment was 37%. In high-risk neuroblastoma ¹³¹I-MIBG is being combined with other compounds such as Topotecan (12).

 ¹³¹I-MIBG in recurrent neuroblastoma. The first experience with ¹³¹I-MIBG in patients with recurrent neuroblastoma after previous treatment with chemotherapy or high dose chemotherapy combined with stem cell rescue, led to palliation as well as temporarily complete remissions and life prolongation in a considerable number of them (13). Thrombocytopenia was seen in 82% especially in patients pre-treated with platinum. The addition of hyperbaric oxygen (Fig. 3) led to an increase in 2-year survival in comparison with ¹³¹I-MIBG alone (14). Recently vitamin C has been added to the ¹³¹I-MIBG/hyperbaric oxygen schedule. Neuroblastoma contains high levels of ferritin (an iron binding protein) and addition of vitamin C may cause extensive free radical related damage within neuroblastoma cells.