Test–Retest Reproducibility of ¹⁸F-FDG PET/CT Uptake in Cancer Patients Within a Qualified and Calibrated Local Network

Abstract

Calibration and reproducibility of quantitative 18 F-FDG PET measures are essential for adopting integral 18 F-FDG PET/CT biomarkers and response measures in multicenter clinical trials. We implemented a multicenter qualification process using National Institute of Standards and Technology-traceable reference sources for scanners and dose calibrators, and similar patient and imaging protocols. We then assessed SUV in patient test-retest studies. Methods: Five 18 F-FDG PET/CT scanners from 4 institutions (2 in a National Cancer Institute-designated Comprehensive Cancer Center, 3 in a community-based network) were qualified for study use. Patients were scanned twice within 15 d, on the same scanner (n 5 10); different but same model scanners within an institution (n 5 2); or different model scanners at different institutions (n 5 11). SUV max was recorded for lesions, and SUV mean for normal liver uptake. Linear mixed models with random intercept were fitted to evaluate test-retest differences in multiple lesions per patient and to estimate the concordance correlation coefficient. Bland-Altman plots and repeatability coefficients were also produced. Results: In total, 162 lesions (82 bone, 80 soft tissue) were assessed in patients with breast cancer (n 5 17) or other cancers (n 5 6). Repeat scans within the same institution, using the same scanner or 2 scanners of the same model, had an average difference in SUV max of 8% (95% confidence interval, 6%-10%). For test-retest on different scanners at different sites, the average difference in lesion SUV max was 18% (95% confidence interval, 13%-24%). Normal liver uptake (SUV mean ) showed an average difference of 5% (95% confidence interval, 3%-10%) for the same scanner model or institution and 6% (95% confidence interval, 3%-11%) for different scanners from different institutions. Protocol adherence was good; the median difference in injection-to-acquisition time was 2 min (range, 0-11 min). Test-retest SUV max variability was not explained by available information on protocol deviations or patient or lesion characteristics. Conclusion: 18 F-FDG PET/CT scanner qualification and calibration can yield highly reproducible test-retest tumor SUV measurements. Our data support use of different qualified scanners of the same model for serial studies. Test-retest differences from different scanner models were greater; more resolution-dependent harmonization of scanner protocols and reconstruction algorithms may be capable of reducing these differences to values closer to same-scanner results. by on August 3, 2020. For personal use only. jnm.snmjournals.org Downloaded from FIGURE 4. Bland-Altman plot of liver SUV mean (n 5 23). Light-green circles 5 same scanner; dark-green circles 5 different scanners from same site; gray circles 5 different scanner models from different sites; dashed lines 5 average difference and 95% limits of agreement.

Evaluation of 18F-FDG PET/CT images acquired with a reduced scan time duration in lymphoma patients using the digital biograph vision

“…2 ), which we previously defined as the acceptable margin of error. Of note, a recent study by Kurland et al [ 17 ] demonstrated that lesion uptake (SUVmax) showed an average difference of 8% for the same scanner model within the same institution and 18% for different scanners from different institutions. No notable differences were observed between SUVmax and SUVpeak measurements and between low, moderate and high tracer uptake.…”

Tumor Subregion Evolution-Based Imaging Features to Assess Early Response and Predict Prognosis in Oropharyngeal Cancer

“…The proposed imaging signature should be further tested in independent, prospective studies. Issues such as repeatability and reproducibility should be addressed for multicenter validation as proposed in previous studies (41)(42)(43). Another limitation is that the cohort includes both HPV-positive and HPV-negative tumors.…”

Application of PET Tracers in Molecular Imaging for Breast Cancer

“…A high test-retest interclass correlation coefficient (ICC) of 0.90 and 0.91 was found for SUV max and SUV mean , respectively. Reproducibility across different scanners was assessed in 23 patients, 17 with BC [13]. Patients underwent two [ 18 F]-FDG-PET/CT scans within 15 days on the same scanner or on different scanners at different sites.…”