Nuclear medicine imaging in lung cancer

The evaluation of the anatomical dissemination of lung cancer has a pivotal role in the choice of the most appropriate treatment modality. The techniques of nuclear medicine are founded on the use of different radiopharmaceuticals capable of exploiting the specific characteristics of malignant tissues. They may recognise diverse cell densities, growth rates, metabolic pathways, antigenic and surface receptor expressions. In the past, the use of Co-57-bleomycin and, then, of (67)Gallium has encountered a mixed acceptance among nuclear medicine specialists, with favourable reports claiming their utility, and others with more sceptical opinions. It is generally admitted that both Co-57-bleomycin and (67)Gallium scintigraphies are quite sensitive and rather accurate. Their use, however, is almost abandoned in favour of more innovative and encouraging approaches, including non-specific radio-tracers ((201)Thallium and Tc-99m-sestamibi), substances useful in particular clinical applications (the somatostatin analogues I-123-tyr(3) and the In-111 octreotide for neuronendocrine tumours), radio-labelled monoclonal antibodies, and the recently introduced positron emission tomography. Promising results with each of these techniques need to be further substantiated, before their entering into clinical practice. However, the abundance of choices offered by nuclear medicine might reasonably bring forward the ideal noninvasive test. We review the many scintigraphic methods investigated so far and their clinical significance.