RESUMO
Although promising results with radioimmunotherapy and radioimmunodiagnosis in haematological diseases, have been reported, they are less encouraging results in solid tumours. Experimental mathematical models suggest that optimization of antibody-based therapy and diagnosis is possible and that further research towards improvement is warranted. In this review, the major problems of radioimmunotherapy and diagnosis are discussed. Particular items adressed include tumour uptake of antibodies and antibody-fragments, the target/non-target ratio, immunogenicity and the selection of radionuclides.
Assuntos
Neoplasias/diagnóstico por imagem , Neoplasias/radioterapia , Radioimunodetecção , Radioimunoterapia , Anticorpos Monoclonais/uso terapêutico , Humanos , Radioimunodetecção/efeitos adversos , Radioimunodetecção/métodos , Radioimunoterapia/efeitos adversos , Radioimunoterapia/métodos , RadioisótoposRESUMO
Enhancement of antigen expression could result in improved tumour targeting using antibodies directed to the antigen. In this study we performed radioimmunoscintigraphy using 99mTc-CEA-Scan to analyse the effect of interferon-alpha (IFN-alpha) in enhancing the expression of carcinoembryonic antigen (CEA) in ten patients with CEA-producing tumours. Furthermore, we investigated the feasibility of a future therapeutic study with this antibody fragment labelled with rhenium-186. Although IFN-alpha gave rise to a significant increase in antibody uptake by the tumour, the absolute antibody uptake in the tumour appeared to be poor, with a mean of 0.475% of injected dose (ID) in the tumour before IFN-alpha, rising to 0.562% ID in the tumour after IFN-alpha. Pharmacokinetic analysis demonstrated no significant alterations after IFN-alpha. In conclusion, the administration of IFN-alpha is an attractive way to achieve enhanced tumour targeting, although the increase was of little clinical significance in this patient population and using this antibody fragment.
