Purpose: The aim of this study is to examine the reproducibility of anti-1-amino-3-[(18)F]fluorocyclobutane-1-carboxylic acid (anti-3-[(18)F]FACBC) quantitative measurements in key background structures and untreated malignant lesions.
Procedures: Retrospective review of 14 patients who underwent follow-up anti-3-[(18)F]FACBC positron emission tomography-X-ray computed tomography (PET-CT) for prostate carcinoma recurrence. Standard uptake values (SUV) were measured in both original and follow-up scans in key background structures and untreated malignant lesions. Absolute and percent mean difference in SUV between scans and interclass correlation coefficients (ICC) were also computed.
Results: Mean (±SD, range) scan interval was 17.4 months (±7.1, 4-29). %Mean difference in SUVmean was <20 % in background structures with low absolute differences. ICCs were >0.6 except for early-phase blood pool (ICC = 0.4). SUVmax in malignant lesions without interim therapy increased or remained stable over time.
Conclusions: Despite variable time interval between scans, FACBC PET-CT demonstrates acceptable reproducibility in key background structures. Untreated malignant lesions showed stable or increased uptake over time. A formal test-retest study is planned.