“…These tracers have been successfully applied in oncology, such as for the detection of endocrine tumours using somatostatin analogs (Krenning et al, 1989), specific receptor radiotracers for the brain (Wagner et al, 1983), radiolabelled epidermal growth factor in gynaecology (Schatten et al, 1990), radiolabelled oestrogen analogs in breast cancer (Pavlik et al, 1990) or galactose-terminated neoglycoalbumin (NGA) in primary and secondary liver cancer (Virgolini et al, 1989b). 9'Tc-NGA is one of the first chemically synthetised receptor radiopharmaceuticals introduced for in vivo use in humans (Vera et al, 1984;Stadalnik et al, 1985;Virgolini et al, 1989aVirgolini et al, ,b, 1991Virgolini et al, , 1992.…”