The utility of the nonattenuation corrected 18F-FDG PET images in the characterization of solitary pulmonary lesions

Objective To determine the accuracy of nonattenuation corrected (NAC) F-18-fluorodeoxyglucose positron emission tomography (F-18-FDG PET) images in the evaluation of solitary pulmonary lesion as compared with more established methods. Methods Fifty-six patients received F-18-FDG PET/CT for diagnosing solitary pulmonary nodules or mass lesions based on histopathology (n=39) and clinical follow-up (n=17). Visual pulmonary lesion FDG uptake was graded by consensus of two nuclear medicine physicians on both attenuation corrected (AC) [absent, less than mediastinal blood pool (MBP), equal to MBP, greater than MBP] and NAC (absent, less than skin, equal to skin, greater than skin) images. Standardized uptake values (SUV) were also measured from AC images. SUV, visual AC, and visual NAC methods' diagnostic performances were compared, distinguishing benign from malignant pulmonary nodules. Results There were 34 malignant and 22 benign lesions. Lesion diameter varied from 5 to 100mm (mean +/- SD, 24.0 +/- 17.9 mm). The NAC, AC, and SUV method sensitivities and specificities were 100/64%, 91/59%, and 79/77%, respectively. For lesions less than 3 cm, NAC, AC, and SUV methods yielded accuracies of 85%, 78%, and 73%, respectively. The NAC method was the most sensitive and accurate especially for small nodules. Conclusion Visual assessment of NAC F-18-FDG PET images alone may provide a more accurate characterization of solitary pulmonary lesions. Nucl Med Commun 31: 945- 951 (C) 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.