Comparative efficacy of positron emission tomography with fluorodeoxyglucose in evaluation of small (< 1 cm), intermediate (1 to 3 cm), and large (> 3 cm) lymph node lesions

Purpose: Our objective was to determine if positron emission tomography (PE T) with fluorodeoxyglucose (FDG; PET-FDG) imaging is equally efficacious in detection of metastases in small and large mediastinal lymph nodes as comp ared to CT scanning. Materials and methods: PET-FDG imaging, CT scanning, and histology results of sampled mediastinal lymph nodes were compared in 54 patients of total 11 8 patients studied. Efficacy of PET and CT was determined and compared in s mall (< 1 cm), intermediate (1 to 3 cm), and large (> 3 cm) mediastinal les ions. Results: PET was accurate in 94% of patients in characterizing "N" disease as compared to 61% with CT. Overall, sensitivity, specificity, and accuracy of PET for staging mediastinal lymph nodes (n 168 in 54 patients) was 96, 93, and 94%, as compared to 68, 65, and 66% with CT. Positive and negative predictive value of PET in detecting mediastinal adenopathy was 86% and 98% , as compared to 47% and 82% with CT, respectively. PET was also highly rel iable and accurate for detecting lymph nodes < 1 cm, 1 to 3 cm, and > 3 cm in size with superior efficacy than CT. Sensitivity, specificity, and accur acy of PET for detecting malignancy in lymph node lesions < 1 cm in size wa s 97, 82, and 95%, respectively. Conclusion: PET-FDG imaging is equally reliable and accurate for detecting disease in small and large lymph node lesions in patients with suspected or proven lung cancer with better efficacy than CT.