Impact of dual-time-point 18 F-FDG PET imaging and partial volume correction in the assessment of solitary pulmonary nodules

Purpose Our aim was to assess the diagnostic potential of 18 F-FDG PET using partial volume correction and dual-time-point imaging in the assessment of solitary pulmonary nodules. Methods We included 265 patients in this retrospective study (171 men; 94 women; age range, 41–92 years). All had pulmonary nodules on CT, and diagnosis was confirmed by biopsy or follow-up CT. All underwent whole body FDG PET, 60 min after FDG injection. Of the 265 patients, 255 underwent second FDG PET for chest 100 min after injection. Maximum SUVs for nodules were calculated from both scans. Partial volume correction for first time SUVs was applied, using coefficient factor. Malignancy was defined using the following criteria: (1) Visual assessment; (2) First time SUV ≥ 2.5; (3) Partial volume corrected first time SUV ≥ 2.5; (4) second time SUV ≥ 2.5; (5) Increase in SUV over time; (6) Increase or no change in SUV; (7) First time SUV ≥ 2.5 and/or increase or no change in SUV. Results Biopsy and follow-up revealed 72 malignant lung nodules and 193 benign nodules. Sensitivity, specificity and accuracy for the five criteria were as follows: (1) 97, 58 and 68%; (2) 65, 92 and 85%; (3) 84, 91 and 89%; (4) 90, 80 and 83%; (5) 84, 95 and 92%; (6) 92, 92, and 92%; (7) 95, 90 and 91%, respectively. Conclusion Dual-time-point 18 F-FDG PET has potential impact on improving the diagnostic accuracy for malignant lung nodules. Dual-time-point 18 F-FDG PET imaging should be included in the clinical work-up of patients with pulmonary nodule.