Dual-time-point FDG PET/CT: Is It Useful for Lymph Node Staging in Patients with Non-Small-Cell Lung Cancer?

Abstract

Purpose Dual-time-point (DTP) FDG PET/CT has been shown to be useful for lymph node (LN) staging in patients with non-small-cell lung cancer (NSCLC). The aim of this study was to evaluate the LN staging ability of DTP FDG PET/CT in the predominant area of pulmonary tuberculosis. Methods Sixty-nine NSCLC patients underwent DTP PET/ CT. Regions of interest were placed on each LN of each station, and the maximum SUVs were measured. Three variables were obtained: (1) the SUV on the early scan (SUV early ), (2) the SUV on the delayed scan (SUV delayed ), and (3) the retention index of the SUV (RI). Each patient had one final LN stage and three other LN stages according to the cutoff values of SUV early , SUV delayed , and RI. Results In the LN-based analysis, the area under the ROC curve of SUV delayed (0.884) was significantly larger (P< 0.01) than those of SUV early (0.868) and RI (0.717). Among the three variables, SUV delayed was more accurate (P<0.01) for detecting the mediastinal LN metastasis than SUV early and RI. In the patient-based analysis, SUV delayed had correctly determined LN stages in 55 of 69 patients (sensitivity, specificity, and accuracy088.7 %, 50.0 %, and 79.7 %), whereas SUV early and RI correctly determined LN stages in 53 and 52 patients, respectively. Conclusions In this study, comparing the diagnostic efficacy of SUV early , SUV delayed , and RI for LN staging in patients with NSCLC, SUV delayed was the most accurate variable for LN staging. DTP PET/CT could provide improved diagnostic accuracy for the LN staging of NSCLC.

Characteristics of Metastatic Mediastinal Lymph Nodes of Non-Small Cell Lung Cancer on Preoperative F-18 FDG PET/CT

“…Adenocarcinoma is known for low FDGavidity [29]. In this study, many adenocarcinoma cases were included, and adenocarcinoma showed a significantly lower SUVmax than squamous cell carcinoma.…”

“…There are reports that F-18 FDG uptake by mediastinal lymph nodes was correlated with that by the primary nonsmall cell lung cancer [28,29]. Under the assumption that the ratio of two SUV values would be the significant variable, we evaluated the LN SUV/primary tumor SUV ratio.…”

Update on nodal staging in non-small cell lung cancer with integrated positron emission tomography/computed tomography: a meta-analysis

“…In this respect, diffusion-weighted imaging of magnetic resonance imaging (MRI) might have a role in nodal staging of NSCLC [36]. In addition, dual time point PET/CT, obtaining delayed images might have a complementary role in nodal staging [25]. Although none of the studies included in this meta-analysis stated the use of time-of-flight (TOF) PET, TOF PET has known to provide a gain in image signal-to-noise ratio, lesion detectability, and accuracy of lesion uptake measurement [49].…”

Diagnostic value of dual time-point 18 F-FDG PET/CT versus single time-point imaging for detection of mediastinal nodal metastasis in non-small cell lung cancer patients: a meta-analysis

“…Currently, the initial scan imaging is usually acquired after a minimum delay of 45 min for radiotracer distribution; however, there is no generally optimal delay time for either the initial time-point scan imaging or the time interval between the initial and delayed time points of image acquisition. In five of the included studies (10,(12)(13)(14)(15), imaging acquisition was performed 60 min and 120 min after the first injection. The other three studies (11,16,17) stated that delayed-scan imaging was obtained at 180 min, and one study (17) used 45 min as the initial scan time.…”

“…A total of 654 patients were included in the analysis, with ages in the range of 35-89 years. One study (16) enrolled patients prospectively, four studies (11,(13)(14)(15) enrolled retrospectively, and the enrolling procedures of three studies (10,12,17) were unclear. Additionally, the patient selection in three studies (13,15,16) was performed in a consecutive manner, while the other five studies (10-12,14,17) did not report this information.…”