Clinical study of radioisotope uptake mechanisms in 33 brain lesions by comparative use of Na131I and SAIR

It is suggested that an isotope of small molecular size, not bound to proteins (NaI), would pass more easily into little-differentiated tumours and vascular syndromes due chiefly to a lesion of the hematoencephalic barrier (HEB). On the other hand iodinated serumalbumine (SAIR), a large organic molecule accumulating in abnormal extracellular spaces, should in principle be a better indicator in non-primitive tumours and highly differentiated tumours of the SNC. The clinical study reported confirms this hypothesis. Non-primitive tumours, meningiomas, metastases, sarcomas, are shown more clearly by SAIR (especially in meningiomas, nearly 90% of cases). In non-primitive tumours the difference in behaviour between NaI and SAIR does seem to depend on the degree of differentiation of the tumour. Thus in so-called benign gliomas the NaI uptake is greater, whereas in highly differentiated gliomas the advantage goes to SAIR. In one case of circulation deficiency a vascular type of hyperfixation was observed with NaI, while SAIR showed practically nothing