Objective: The objective of our study was to investigate whether fluorodeoxyglucose (FDG) positron emission tomography scanning uptake impacts the yield of transbronchial needle aspiration (TBNA).
Methods: We carried out a retrospective analysis of data from 140 consecutive patients (178 lymph nodes) undergoing positron emission tomography-computed tomography scanning and subsequent TBNA with rapid onsite cytologic evaluation of the specimen. Patient and lymph node characteristics, including nodal station, size, FDG uptake, number of passes with the needle, sample adequacy, and the final diagnosis were recorded.
Results: The diagnostic yield of TBNA was 75%. Themean short axis lymph node diameter was 18.7+/-9 mm and mean maximum standardized uptake value (SUVmax) was 7.7+/-4. The diagnostic yield depended on the lymph node size [odds ratio (OR)=1.07 (1.00-1.14); P=0.04], clinical suspicion of malignancy [OR=5.13 (1.95-13.52); P=0.001], malignant diagnosis [OR=4.91 (1.71-14.09); P=0.003], and FDG uptake [for SUVmax cutoff of 3.0: OR=33.8 (9.2-124); P<0.001]. Only clinical suspicion of cancer [OR=6.2 (2.2-17.2); P=0.001] and FDG uptake [for SUVmax cutoff of 3.0: OR=33.8 (9.2-123.8); P<0.001] remained significant on multivariate analysis. Receiver operating characteristic curves combining 3 key variables (lymph node size, clinical suspicion of malignancy, and SUVmax) showed an area of 0.83 under the curve for a 2.5 SUVmax cutoff and 0.84 for a 3.0 cutoff.
Conclusions: FDG uptake is the single most important variable impacting the TBNA yield. TBNA of lymph nodes with an SUVmax less than 3.0 is rarely diagnostic.