[Positron emission tomography using 18-FDG-PET in radiologically indeterminate pulmonary lesions]

Fluorine-18 deoxyglucose Positron Emission Tomography (FDG-PET) is a non-invasive technique that offers the possibility to define if the radiologically indetermined pulmonary lesions are benign or malignant with high positive and negative predictive values. Considering the indexed literature we can observe that there are few original studies performed with the diagnostic possibilities of our means. For this reason, our main objective is to evaluate the diagnostic accuracy of positron emission tomography in sixty-seven radiologically indetermined pulmonary nodular lesions.

Retrospectively, we evaluated the diagnostic ability of FDG-PET globally (by means of visual and semiquantitative analysis) and partially (only considering the Standardized Uptake Value (SUV)), in sixty-seven patients confirmed by pathology or clinical and radiological monitoring, in a time interval superior to one year.

Globally, FDG-PET had a sensitivity (S) of 92%, specificity (SP) of 86.6%, positive predictive value (PPV) of 89.4%, negative predictive value (NPV) of 89.6% and diagnostic accuracy (DA) of 89%. The best results were obtained for an SUV equal or superior to 2.5. With this value, the clinical efficacy parameters were: S 0.92, SP 0.90, PPV 0.92, NPV 0.90 and DA 0.91.

We can characterize most of the radiologically indetermined pulmonary lesions by FDG-PET. The additional use of SUV facilitates an increase in the positive predictive value and specificity of FDG-PET.