131I]metaiodobenzylguanidine therapy after conventional therapy for neuroblastoma.

[131I]Metaiodobenzylguanidine (131I-MIBG) is used for diagnostic scintigraphy and targeted therapy in a range of neural crest tumors, which exhibit an active uptake-1 mechanism at the cell membrane and cytoplasmatic storage in neurosecretory granules. A good and selective concentration and a long retention in the tumor, as is generally the case in neuroblastoma, are the basis for successful 131I-MIBG treatment. At The Netherlands Cancer Institute a phase II study was carried out in 53 patients with progressive recurrent disease after conventional therapy had failed. Despite the unfavorable basis for treatment, 131I-MIBG therapy induced 7 complete remissions, 23 partial remissions and arrest of disease (no change) in 10. Nine patients had progressive disease and one patient was lost to follow-up. The palliative effect of the treatment under these conditions was impressive. The duration of remissions varied from 2 to 38 months. The best results were obtained in patients with voluminous soft tissue disease. In general the treatment was well tolerated by children and the toxicity was mild, provided the bone marrow was not invaded by the disease. It is concluded that 131I-MIBG therapy has a definitive place in the treatment of neuroblastoma after conventional treatment has failed. As the invasiveness and toxicity of this therapy compare favorably with that of chemotherapy, immunotherapy and external beam radiotherapy, 131I-MIBG therapy is the best palliative treatment for patients with advanced recurrent neuroblastoma.     

131I uptake in human thyroid after antidote treatment for mixed fission products contamination

The efficacy of a mixed antidote treatment in blocking 131I uptake in humans was investigated in two volunteers. Simultaneous oral administration of 10 g of calcium alginate, 3 g of ferrihexacyanoferrate (II) and 130 mg of potassium iodide 30 min before 131I administration caused an almost complete block of the 131I thyroid uptake in both subjects. This indicated that calcium alginate and ferrihexacyanoferrate (II) had no influence on the blocking effect of potassium iodide on 131I thyroid uptake. This finding is important because mixed antidote treatment is the recommended treatment in cases of accidental exposure to mixed fission products.     

131I]metaiodobenzylguanidine treatment of a malignant paraganglioma.

The bone metastases of a malignant, non-secreting paraganglioma were treated with [131I]metaiodobenzylguanidine (131I-MIBG) over a 10-year period. Initial treatment (131I-MIBG: 9.6 GBq) resulted in a decrease in the number of bone metastases from 16 to 2. At three years, a relapse with primary tumor regrowth and liver metastasis was again treated with 131I-MIBG (22.2 GBq). A decrease in the number of bone metastases and MIBG uptake was again observed.     

The use of [131I]metaiodobenzylguanidine in the treatment of neuroblastoma after conventional therapy.

Eleven cases of neuroblastoma (10 males and 1 female; 9 aged 1-13 years, and two aged 17 and 38 years, respectively) ten of which were refractory to chemotherapy, were submitted to treatment with [131I]metaiodobenzylguanidine (131I-MIBG). The therapeutic procedure consisted essentially of single doses (2.6-9.5 GBq) of 131I-MIBG mostly split into two parts, administered by slow i.v. infusion and given in several therapeutic courses, usually at 1-2 month intervals. The treatment resulted in: 1 complete response, 1 partial response, 1 minor response, 4 stabilized diseases and 2 progressive diseases (two patients were not evaluable due to rapid progression of the disease). Pain relief was observed in all cases and particularly in four patients who suffered severe tumor pain. The major side-effects recorded were: hypertensive crises over a 6-day period in one case, fever lasting a few days in another and bone marrow depression in two intensively pretreated patients. A slight hematologic toxicity was observed, however, in almost all cases.     

131I]metaiodobenzylguanidine in neuroblastoma patients at diagnosis.

Treatment of resistant neuroblastoma with high dosage [131I]metaiodobenzylguanidine (131I-MIBG) appears effective since encouraging results have been obtained so far even in patients with very advanced, intensively pre-treated disease. We have already reported a stage III NB patient treated at diagnosis, who is at present in complete remission with a 4-year follow-up. To further explore the potential role of this new drug in untreated patients, we administered radionuclide to two children with stage III neuroblastoma. Both cases received 131I-MIBG at relatively low doses, and showed a significant reduction of the tumor mass and, interestingly enough, no evidence of 131I-MIBG uptake of a tracer dose in the remaining tumor. Particularly in case 1, the permanence and subsequent progression of the part of the tumor mass without 131I-MIBG uptake, after therapeutic doses of 131I-MIBG which apparently destroyed the 131I-MIBG-positive cell population, clearly suggest heterogeneity at diagnosis, with a dual neuroblastoma cell population, one with 131I-MIBG uptake and the other without. Aside from the biological implications of the heterogeneous MIBG uptake in neuroblastoma at diagnosis, our findings suggest that in stage III neuroblastoma patients even a relatively small dose of 131I-MIBG administered at diagnosis is sufficient to either completely destroy the primary tumor, as reported by our group, or to destroy that part of the tumor which shows 131I-MIBG uptake (as in the present cases), without any significant hematologic toxicity. Furthermore, a single course of 131I-MIBG at the dosage employed here does not appear to jeopardize the subsequent use of chemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Results of [131I]metaiodobenzylguanidine treatment in metastatic carcinoid.

The results obtained with [131I]metaiodobenzylguanidine (131I-MIBG) treatment in 6 patients affected by metastatic carcinoid are reported. 131I-MIBG was given in single doses of 3.7-8.0 GBq, reaching a maximum cumulative dose of 29.5 GBq in 4 courses. Objective responses were not observed, but in 4 cases an apparent stabilisation of the disease for more than 1 year was obtained. A subjective response regarding the carcinoid syndrome was observed in 4 cases. No response was seen in 2 cases. No adverse side-effects of any importance were observed, usually being prevented by a mild medication.     

Results of [131I]metaiodobenzylguanidine treatment in metastatic malignant phaeochromocytoma.

The results obtained with [131I]metaiodobenzylguanidine (131I-MIBG) treatment in 6 patients affected by metastatic phaeochromocytoma are reported. Single doses of 3.7-7.4 GBq were given, in 1-6 courses, up to cumulative doses of 5.4-37.8 GBq. Objective responses were observed in 5 patients (2 tumour shrinkages, even if small; 5 lowering of blood pressure), which were only temporary in 3 patients and stable in 2. Complete disappearance of pain was obtained in 2/2 patients. No adverse side-effects were observed. The problem of treatment strategy in situations of stable disease deserves further study.     

131I]metaiodobenzylguanidine therapy in 20 patients with malignant pheochromocytoma.

Twenty patients, 16 male and 4 female (aged 11-76 years), with metastatic pheochromocytoma were treated in our Institution between 1985 and 1990. Metastases occurred in all patients: at presentation in 11 patients, with a 10 to 30 month delay in 7 patients, and 9 and 28 years later respectively in 2 patients. Catecholamines hyperproduction was present in all patients. Metaiodobenzylguanidine (MIBG) uptake was found in 16 patients after a diagnostic dose and only after a therapeutic dose in 1 patient. Surgery was performed on primary tumor (18 patients) and on distant metastases (10 patients). 131I-MIBG therapy was performed in 11 patients, 9 of whom were evaluable. The cumulative activity ranged from 3.7 to 26.3 GBq (100 to 711 mCi) in 1 to 6 courses. We observed symptomatic improvement (5 patients) and partial tumor response in 2 patients, which lasted for 28 and 9 months respectively, terminating with a rapidly progressing disease involving the bone marrow. Stabilisation was observed in 3 patients. Moderate myelosuppression occurred in 4 patients. Fifteen patients died with a median survival of 16 months (range 3-60). Response to therapy was poor and further evaluation of the presently available therapeutic approaches is needed.     

Efficacy and safety of [131I]metaiodobenzylguanidine therapy for patients with refractory neuroblastoma.

Metaiodobenzylguanidine (MIBG) is a guanethidine derivative that is selectively concentrated in sympathetic nervous tissue. MIBG labeled with 123I or 131I has proven to be a specific and sensitive tool for detection of primary and metastatic pheochromocytoma and neuroblastoma. Eleven patients, with refractory stage IV neuroblastoma were treated with a total of 23 courses of 131I-MIBG, 100-400 mCi/m2/course. Total activity administered per course ranged from 90-550 mCi; maximum cumulative radioactivity per patient was 1356 mCi. The 131I-MIBG was given as a 2 hour infusion. Total body dose was calculated from whole body activity measurements, ranging from 73-250 cGy. The main toxicity was thrombocytopenia, with platelet nadirs to less than 25,000/microL in 5/23 courses (5 patients), all occurring in patients with greater than 25% replacement by tumor in the bone marrow. Neutropenia to a nadir of less than 500/microL was seen in only 2 patients, both with greater than 50% bone marrow replacement after 2 and 4 courses of 131I-MIBG, respectively. Tumor doses were calculated in patients with an evaluable measurable lesion, and ranged from 312-6329 cGy per course. Two of the eleven patients had partial responses, with one long-term survivor with stage IV neuroblastoma with no evidence of active disease now 4 years off treatment. Two other patients survive with stable disease after 3 treatments, at 3+ and 5+ months. Seven patients died with progressive disease. This study shows that treatment with 131I-MIBG is safe and can be effective in refractory neuroblastoma, particularly in patients who do not have extensive bone and bone marrow involvement.