Autoradiographic detection of neuroblastoma cells in bone marrow

Autoradiography with 125J m-iodobenzylguanidine and 3H-norepinephrine is an easily performed method for the detection of very small amounts of neuroblastoma cells in bone marrow. Taking into account that the time of exposition is about one week using 3H-norephinephrine the method is suitable for diagnostic purpose, such as distinguishing a true remission from a virtuell one, for the detection of a bone marrow recurrence or staging patients in stage III or stage IV. In a preliminary clinical study bone marrow of nine children has been examined for neuroblastoma cells. In three children no bone marrow involvement was found, neither in the usual cytological examination nor in autoradiography. In the bone marrow of five out of the other six children neuroblastoma cells were detectable by autoradiography and it was possible to quantify the involvement. The only child whose neuroblastoma cells were not detectable by autoradiography lacked of elevated urinary catecholamines and the tumor was primarily negative for catecholamines. This method detects a biochemically defined population of neuroblastoma cells in bone marrow, which are able to synthesize the neurotransmitter norepinephrine or to actively adsorb it. These relatively well differentiated neuroblastoma cells are especially accessible to therapies such as treatment with 131J m-iodobenzylguanidine or 6-hydroxydopamine. (orig.)