Anti-3-¹⁸F-FACBC (¹⁸F-Fluciclovine) PET/CT of Breast Cancer: An Exploratory Study

Abstract

The purpose of this study was to explore the uptake of the synthetic amino acid analog PET radiotracer anti-3-18 F-FACBC ( 18 F-fluciclovine) in breast lesions with correlation to histologic and immunohistochemical characteristics. Methods: Twelve women with breast lesions underwent 45-min dynamic PET/CT of the thorax after intravenous administration of 366.3 ± 14.8 (337.44-394.05) MBq of 18 F-fluciclovine. Uptake in the primary lesions at 4 representative time points (5, 17, 29, and 41 min) after injection were correlated with histologic, imaging, and clinical findings. The significance of differences in SUV max and tumor-to-background ratios between malignant and benign tissue were calculated. Correlations of activity to histologic and immunohistochemical cancer subtypes were made including Ki-67 intensity and Nottingham grade (NG). Results: There were 17 breast lesions (4 benign, 13 malignant) including 7 of 13 invasive ductal, 5 of 13 invasive lobular, and 1 of 13 metaplastic carcinomas. There was a significant difference in mean SUV max ± SD of malignant (6.2 ± 3.2, 6.0 ± 3.2, 5.7 ± 2.8, and 5.6 ± 3.0) versus benign (1.3 ± 0.6, 1.2 ± 0.5, 1.2 ± 0.6, and 1.1 ± 0.5) lesions at 5, 17, 29, and 41 min, respectively (all P # 0.0001). Tumor-tobackground (aorta, normal breast, and marrow) ratios were also significantly higher in malignant than benign breast lesions (all P # 0.02). The highest 18 F-fluciclovine activity seems to be present in triplenegative and NG3 subtypes. . In 7 patients, 18 F-fluciclovine PET visualized locoregional and distant spread including that of lobular cancer, though identification of hepatic metastases was limited by physiologic background activity. Conclusion: The uptake characteristics of 18 F-fluciclovine are reflective of the histologic and immunohistochemical characteristics in suspected breast lesions with greater activity in malignant versus benign etiology. The data from this exploratory study may be useful to design future studies using 18 F-fluciclovine PET for breast tumor imaging as well as for detection of locoregional and distant spread.

18F-Fluciclovine (FACBC) and Its Potential Use for Breast Cancer Imaging

“…Because amino acid transport is upregulated in many types of cancer, 18 F-fluciclovine has potential application in multiple types of cancer. In this issue of The Journal of Nuclear Medicine, 2 groups report promising preliminary results for FACBC in women with breast cancer naïve to therapy (2,3). These studies demonstrated substantially higher uptake of 18 F-fluciclovine in primary and metastatic breast cancers than in benign breast lesions and normal breast tissue.…”

“…The report from the Emory group, by Tade et al (2), evaluated 18 F-fluciclovine PET/CT in 12 women with malignant (n 5 13) and benign (n 5 4) breast lesions with histologic verification. In this study, patients underwent dynamic 18 F-fluciclovine PET/CT of the thorax for 45 min.…”

Synthesis and biological properties of radiohalogenated α,α‐disubstituted amino acids for PET and SPECT imaging of amino acid transporters (AATs)

“…Anti-3-[ 18 F]-FACBC (7) was shown to be more efficacious than [ 111 In]-Prostascint in detecting recurrent prostate cancer and has recently been approved by the FDA as Axumin for prostate cancer. In a series of preliminary studies in humans, anti-3-[ 18 F]FACBC (7) was observed to show increased uptake in lung, 98 breast, 99,100 and renal 101 lesions, whereas anti-2-[ 18 F]FACPC (12) showed uptake in metastatic prostate cancer. 102,103 The transport mechanism of the AAs anti-3-FACBC (7) has been elucidated in human prostate cancer 17,18,[104][105][106][107] and glioma 105 cells.…”

Precision Medicine and PET/Computed Tomography

“…Not all tumors are intensely FDG avid such as lobular breast cancer and bronchio alveolar cancer of the lung and it would be difficult to implement FDG PET/CT based early therapy assessment for these cancers. However, a novel PET radiopharmaceutical such as FACBC(18), which demonstrates intense uptake in lobular breast cancer can be successfully deployed. Therefore, selecting a tumor type or molecular subtype, which has moderate to intense avidity for the PET radiopharmaceutical, is fundamentally important.…”