Reproducibility and reliability of anti-3-[¹⁸F]FACBC uptake measurements in background structures and malignant lesions on follow-up PET-CT in prostate carcinoma: an exploratory analysis

Abstract

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.

Conflict of interest statement

Conflict of Interest. Emory University and Dr. Mark Goodman are eligible to receive royalties from anti-3-[18F]FACBC.

Figures

Fig. 1

Correlation of early (4 min) SUVmean on both initial and follow-up scans in background structures.

Fig. 2

Correlation of delayed (17 min) SUVmean of both initial and follow-up scans in background structures.

Fig. 3

a CT, b FACBC PET, and c co-registered image from initial study in a patient with recurrent prostate carcinoma (patient 4 in Table 2) demonstrates abnormal uptake in a 0.6×0.7 cm aortocaval node (arrow). Follow-up study obtained 14 months later with d CT, e FACBC PET, and f co-registered image demonstrates similar uptake in the node (arrow), as well as visualized background structures. The node was biopsy proven to be metastatic prostate carcinoma.