A UK multi-centre study has been carried out to collect medical and dosimetry data from treatments with 131I-metaiodobenzylguanidine (mIBG) for patients suffering from resistant neuroblastoma. All data have been acquired in a standardised way, following strict physics and clinical protocols. The accuracy of three different methods of dose prescription was studied. The results show that the most accurate method involved the use of an initial tracer study to determine the therapeutic activity required to deliver a predetermined absorbed whole-body (WB) dose.