[Scintigraphic imaging of stage III non-small-cell bronchial cancer]

Scintigraphic imagery is a functional image based on the difference of the in vivo concentration of injected radio-active traces as a function-of the metabolic characteristics of the tissues. A positive emission tomography (TEP) relies on an injection of substances which reflect the metabolic activity of the tissues and consist of protein renewal with 11C-methionine or glucose metabolism with F18-fluorodeoxyglucose (FTG). The imagery by TEP enables 85-90% of solitary pulmonary nodules to be detected. The degree of capture of the tracer enables some differentiation of a malignant lesion from a benign lesion which fixes less. In the assessment of the degree of extension in the mediastinal nodes of non-small cell Stage III cancers imagery by TEP has a sensitivity ads specificity which appears superior to those of computed tomography (TEM). The interpretation of the image is simplified by carrying out fusion images between TEM and TEP. The application of TEP in the research into thoracic recurrence has shown a cumulated specificity of 81% and a reliability of 91%. The imagery by TEP is only practised in a few centres. It should be developed in pulmonary pathology if the cost of the apparatus diminishes and if FTG is available. Radioscintigraphy is losing ground in the precise domain of non-small cell carcinoma although it shows up well as a technique in neuro-endocrine tumours. Few studies have shown a decisive value in the radioimmunoscintigraphic evaluation of the extension of mediastinal nodes. A gallium 67 scintigraphy has weak specificity and on account of this has been abandoned for the staging of tumours. Another approach has been isotopic imagery of macrophages but is major inconvenience is a lack of specificity. Scintigraphic studies coupled with ventilation/perfusion remains a useful pre-operative test above all in patients with chronic airflow obstruction with gross tumours at the borderline of operability.