Real-World data show utility of 18F-fluciclovine PET/CT in biochemically recurrent prostate cancer

Use of ¹⁸F-fluciclovine (Axumin) PET/CT changed clinical management in 62% of patients with biochemically recurrent prostate cancer, according to real-world data from an academic center published in Molecular Imaging and Biology.¹

Twelve percent of patients with negative results on conventional imaging had lesion localization on ¹⁸F-fluciclovine PET.

“¹⁸F-Fluciclovine PET/CT remains a useful diagnostic tool in the workup of patients with BCR PC,” authors concluded.

The study retrospectively assessed ¹⁸F-fluciclovine scans of 165 consecutive men with biochemical recurrence after receiving primary definitive treatment. Among these patients, 102 had undergone prostatectomy as their primary treatment and 63 had received radiotherapy.

¹⁸F-fluciclovine PET had an overall positivity rate of 67%. There was an expected incremental increase in the positivity rate as patients’ PSA levels increased, from a low of 15% among patients with a PSA <0.5 ng/ml, to a high of 94% among patients with a PSA ≥5 ng/ml. Overall, the results of ¹⁸F-fluciclovine PET resulted in a change in clinical management in 162 patients.

Additional findings were assessed in 33 patients who received 1 or more other PET imaging, including ¹⁸F-NaF PET/CT (12 patients), ⁶⁸Ga-PSMA11 PET/CT (5 patients), ¹⁸F-DCFPyL PET/CT (20 patients), and ⁶⁸Ga-RM2 PET/MRI (5 patients). Among 14 of these patients, changes to the patient’s treatment plan were made based on further PET imaging with a different radiopharmaceutical.

Prior clinical trial of ¹⁸F-fluciclovine PET/CT

Previous results from a study published in the Journal of Urology showed that ¹⁸F-fluciclovine PET/CT detects metastases better than conventional imaging in patients with high-risk prostate cancer.²

In this clinical trial, 57 patients with high-risk prostate cancer were staged by conventional imaging, including 99mTc-methylene diphosphonate bone scanning and CT or MRI. They then underwent ¹⁸F-fluciclovine PET/CT, followed by robotic radical prostatectomy and extended pelvic lymph node dissection.

¹⁸F-fluciclovine PET/CT detected nodal metastasis with a sensitivity of 55.3% and a specificity of 84.8% in each patient. PET imaging sensitivity and specificity were 54.8% and 96.4%, respectively, per region (right and left pelvis, presacral and nonregional), according to the paper.

The advanced imaging had 22% greater sensitivity for each patient compared with conventional imaging. And ¹⁸F-fluciclovine PET/CT detected regional and nonregional metastases in patients with prostate cancer that went undetected with conventional imaging. PET/CT detected metastases in 7 more patients and 22 more regions and identified distant disease or other cancers in 4 patients.

In the paper, the authors noted that their findings were in line with results of other studies published in the literature.

The FDA approved the radiopharmaceutical ¹⁸F-fluciclovine in May 2016 for PET imaging in men with suspected prostate cancer recurrence based on elevated PSA levels following prior treatment.

References

1. The Clinical Utility of ¹⁸F-Fluciclovine PET/CT in Biochemically Recurrent Prostate Cancer: an Academic Center Experience Post FDA Approval [published online ahead of print January 19, 2021]. Mol Imaging Biol. doi: 10.1007/s11307-021-01583-3

2. Alemozaffar M, Akintayo AA, Abiodun-Ojo OA, et al. [¹⁸F]Fluciclovine positron emission tomography/computerized tomography for preoperative staging in patients with intermediate to high risk primary prostate cancer. J Urol. 2020;204(4):734-740. doi:10.1097/JU.0000000000001095