Nuclear medicine imaging of lung cancer

Two new radiotracers, F-18 FDG and Tc 99m Depreotide (Neotect), parallel advances in imaging equipment, coincident (PET) imaging, and dual detector SPECT scintigraphy are now available in clinical settings. F-18 FDG serc es as a marker of glucose metabolism. Because malignant tissue has an increased rate of anaerobic glycolysis, it is a sensitive, although not totally specific, means to identify malignant tissue. Tt 99m Depreotide identifies several somatostatin-receptor subtypes that have been identified on malignant tumors including adenocarcinoma of the lung and small cell carcinoma. Both techniques are capable of identifying malignant tissue in masses as small as 1 cm with great specificity and equivalent sensitivity to CT imaging. Thus, nuclear scintigraphy provides a noninvasive means to select patients for thoracotomy and to follow their response to therapy.