Non-specific tumor-seeking radiopharmaceuticals--report and future aspects.

A review is made of some currently held views regarding the mechanism of uptake of non-specific tumor-seeking labelled compounds, with special reference to the role of cell membranes and the transfer mechanisms across such membranes. Results with various radiopharmaceuticals used in tumor scintigraphy are discussed and some suggestions are made for possibly profitable research to be done in that area.