Between 7/3/80 and 5/7/86 we gave 32 of our
neuroblastoma patients 62 diagnostic doses of metaiodobenzylguanidine (
MIBG) and 12 patients 20 treatment doses. Our conclusion from our diagnostic dose studies is that
MIBG should be used for staging the extent of
neuroblastoma before
therapy is started, because it may change the proposed staging and
therapy. In
MIBG therapy for
neuroblastoma, our criteria for agreeing to treat a patient are based on calculations from a 4-day tracer dose study that assures that the patient will receive from his first
therapy dose a
tumor dose of at least 2,000 rads/100 mCi, with a total body dose of not greater than 200 rads. Under these circumstances in children, the blood dose has been about 50 rads. The platelet count falls routinely with a 150-rad whole-body dose but never to dangerous levels. We have delivered
tumor doses of 7,000-34,600 rads on the first dose using 150-215 mCi. We have had objective regressions (as shown by before and after CAT scans) of 30-59% in volume of the principal
tumor mass in 3 of the first 12 patients treated. All patients had Grade IV
neuroblastoma with extensive previous surgery, radiation, and
chemotherapy, with and without previous bone marrow transplants.
MIBG therapy was most effective in patients with slower-growing
tumors for whom initial treatment doses were 200 mCi or more.