Update on 18F-Fluciclovine PET for Prostate Cancer Imaging

Abstract

PET is a functional imaging method that can exploit various aspects of tumor biology to enable greater detection of prostate cancer than can be provided by morphologic imaging alone. Anti-1-amino-3-¹⁸F-flurocyclobutane-1-carboxylic acid (¹⁸F-fluciclovine) is a nonnaturally occurring amino acid PET radiotracer that was recently approved by the U.S. Food and Drug Administration for detection of suspected recurrent prostate cancer. The tumor-imaging features of this radiotracer mirror the upregulation of transmembrane amino acid transport that occurs in prostate cancer because of increased amino acid metabolism for energy and protein synthesis. This continuing medical education article provides an overview on ¹⁸F-fluciclovine PET diagnostic capabilities for primary and metastatic disease, including reviews of published comparisons to conventional imaging and other molecular imaging agents. Additionally, the imaging procedure and image interpretation are detailed, including physiologic and pathologic uptake patterns and pitfalls.

Keywords: 18F-fluciclovine; amino acid; prostate cancer.

FIGURE 1.

A 66-y-old man with biochemical recurrence of prostate cancer (PSA level, 29.3 ng/mL). Sagittal ¹⁸F-fluciclovine PET/CT (A), CT (B), and PET (C) found single suggestive focus of uptake in prostate resection bed. Patient underwent external-beam radiation of lesion, with corresponding PSA nadir (0.27 ng/mL)

FIGURE 2.

A 73-y-old man with biochemical recurrence of prostate cancer after prostatectomy and lymphadenectomy (PSA level, 1.02 ng/mL; doubling time, 4.5 mo). Transaxial ¹⁸F-fluciclovine PET (A) and PET/CT (B) found single 0.9-cm retrocaval lymph node with SUV higher than that of bone marrow. Surgical excision was positive for metastasis and subsequent PSA nadir (0.08 ng/mL)

FIGURE 3.

A 50-y-old man with biochemical recurrence of prostate cancer after prostatectomy (PSA level, 3.2 ng/mL; doubling time, 1.4 mo). MRI of abdomen, initially interpreted as negative, and subsequent ¹⁸F-fluciclovine PET/CT found multiple osseous metastases. Shown are transaxial PET/CT (A) and CT (B) through subtle left iliac bone lytic lesion and transaxial PET/CT (C) and CT (D) through silent right acetabular lesion.

FIGURE 4.

Schema of ¹⁸F-fluciclovine PET/CT acquisition adapted from Emory clinical protocol. Maximum-intensity-projection ¹⁸F-fluciclovine images show normal biodistribution. Pancreas uptake is relatively higher than liver uptake, consistent with ideal time of image acquisition after injection. PET bed-position times are after injection (p.i.).

FIGURE 5.

A 60-y-old man with biochemical recurrence of prostate cancer after prostatectomy (PSA level, 16.4 ng/mL; doubling time, 6.4 mo). ¹⁸F-fluciclovine PET/CT found metastatic mediastinal (A) and pulmonary nodules (B) on transaxial PET/CT. Patient was started on hormonal therapy with subsequent resolution of lymphadenopathy and pulmonary nodules and undetectable PSA.

FIGURE 6.

A 60-y-old man with biochemical recurrence of prostate cancer (PSA level, 6.2 ng/mL). ¹⁸F-fluciclovine PET/CT demonstrated uptake in right iliac bone (arrows; without CT correlate) and in prostate bed (not shown) on coronal PET (A) and CT (B). Biopsy of right iliac bone found benign sclerosis. Uptake was linear and ill-defined, atypical of prostate metastases.