The value of dual-time-point¹⁸F-FDG PET/CT for identifying axillary lymph node metastasis in breast cancer patients

Abstract

Objective: The sensitivity of 18-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography (PET) for detecting axillary lymph node (ALN) metastases in breast cancer is reported to be low. Several studies have shown, however, that dual-time-point 18 F-FDG PET imaging provides improved accuracy in the diagnosis of certain primary tumours when compared with single-scan imaging. The purpose of this study was to assess whether the use of dual-time-point 18 F-FDG PET/CT scans could improve the diagnostic accuracy of ALN metastasis in breast cancer. Method: The study included 171 breast cancer patients who underwent pre-operative 18 F-FDG PET/CT scans at 2 time-points, the first at 1 h after radiotracer injection and the second 3 h after injection. Where 18 F-FDG uptake was in the ALN perceptibly increased, the maximum standardised uptake values for both time-points (SUVmax1 and SUVmax2) and the retention index (RI) were calculated. Correlation between the PET/ CT results and post-operative histological results was assessed.Results: The performance of 1 h and 3 h PET/CT scans was equal, with sensitivity 60.3% and specificity 84.7%, in detecting ALN metastasis. Out of 171 patients, 60 had ALNs with increased 18 F-FDG uptake on 1 h or 3 h images. There was no significant difference in RI between the metastatic ALN-positive group and the node-negative group. The area under the receiver operating characteristic (ROC) curve for SUVmax1 was 0.90 (p,0.001) and 0.87 for SUVmax2 (p,0.001). Conclusion: Dual time-point imaging did not improve the overall performance of 18 F-FDG PET/CT in detecting ALN metastasis in breast cancer patients.

Dual-time-point Imaging and Delayed-time-point Fluorodeoxyglucose-PET/Computed Tomography Imaging in Various Clinical Settings

“…24,54,55 Several studies have investigated the applicability of DTPI for improvement of the results from FDG-PET/CT for diagnosis, assessment of axillary lymph nodes, and recurrence of breast cancer. 24,25,[56][57][58][59] Mavi and colleagues 24 in a study of 152 patients with DTPI observed an increase in the uptake of FDG at the second time point in patients with malignant breast lesions. They also noted differences in the increase of FDG uptake, which might reflect the tumor biology.…”

Use of Dual-Point Fluorodeoxyglucose Imaging to Enhance Sensitivity and Specificity

“…56 The study included 171 patients who underwent preoperative DP FDG-PET/CT (1 and 3 hours after radiotracer injection). Where FDG uptake in the axilla was perceptibly increased, the SUVs for both time points and the RI were calculated.…”

Diagnostic Accuracy of 18F-FDG PET/CT in Detection of Local Recurrence in Rectal Cancer and the Added Value of Dual Time Point Scanning

“…In a third study on 26 esophageal cancer patients specificity to detect metastatic lesions was improved when retention index (RI) 10% was used to supplement the early SUVmax of ≥ 2.5 (32) . On the other hand there are other studies that reported no improvement in diagnostic accuracy by the use of delayed imaging (33)(34)(35)(36) . In most of these studies the delayed SUVmax or RI were used separately versus the early SUVmax and not in conjunction with the early SUVmax.…”