This study explored the clinical value of dual time-point 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) imaging for differentiating lymph node metastasis from lymph nodes with reactive hyperplasia.
250 lymph nodes from 153 bladder cancer patients who underwent 18F-FDG PET/computed tomography (CT) delayed diuretic imaging were analyzed. The maximum and mean standardized uptake values (SUVmax and SUVmean, respectively), metabolic tumor volume (MTV), and related delay indices before and after PET delayed imaging were obtained. Relationships with outcomes were analyzed using nonparametric and multivariate analyses. Receiver operating characteristic curves and nomograms were drawn to predict lymph node metastasis.
Delayed PET/CT imaging showed better detection of hyperplasia and metastatic lymph nodes. Delayed imaging with a cutoff SUVmax of 2.0 or 2.5 increased the detection rate of metastatic lymph nodes by 4.1%, and 6.9%, respectively. Delayed imaging often showed speckle-like radioactive foci in lymph nodes with reactive hyperplasia and increased FDG uptake throughout the nodes in metastatic lymph nodes. The lymph node short-axis diameter, SUVmean, and delayed index of MTV (DIMTV) were independent predictors for differentiating metastatic lymph nodes from reactive hyperplasia, and their combination showed better differentiation performance than the individual predictors. In high-risk patients, the probability of lymph node metastasis was as high as 97.6%.
Dual time-point imaging can detect more metastatic lymph nodes. Some lymph nodes with hyperplasia show speckle-like radioactive foci on delayed imaging. The lymph node short-axis diameter, SUVmean, and DIMTV are three important parameters for predicting lymph node metastasis.
Academic radiology. 2024 Mar 01 [Epub ahead of print]
Xiang Zhou, Zehua Lu, Ruixue Zhang, Ruiyun Zhang, Gang Huang, Kuangyu Shi, Haige Chen, Jianjun Liu
Department of Nuclear Medicine, Institute of Clinical Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 1630 Dongfang Rd, Shanghai 200127, China (X.Z., Z.L., G.H., J.L.)., Department of Nuclear Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, 241 Huaihai West Road, Shanghai 200030, China (R.Z.)., Department of Urology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 1630 Dongfang Rd, Shanghai 200127, China (R.Z., H.C.)., Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Street Freiburgstr. 18, Bern 3010, Switzerland (K.S.)., Department of Nuclear Medicine, Institute of Clinical Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 1630 Dongfang Rd, Shanghai 200127, China (X.Z., Z.L., G.H., J.L.). Electronic address: .