Using 18F-fluciclovine-PET/CT imaging versus conventional imaging (CI) alone to guide postprostatectomy salvage radiotherapy significantly improved event-free survival (EFS) in patients with detectable PSA, according to findings from the phase 2/3 EMPIRE-1 trial published in the Lancet.1,2
In the single-center trial the 3-year EFS rate was 75.5% in patients whose radiotherapy plan was finalized based on imaging with the fluciclovine PET radiotracer after an initial treatment assessment using CI. This marked a significant improvement over the 3-year EFS rate of 63% in the control arm of patients receiving radiotherapy based on CI alone (P = .003). The 4-year EFS rates were 75.5% versus 51.2%, respectively (P <.001).
"The decision to offer postprostatectomy radiation is complex, because conventional imaging can leave unanswered questions on the best approach for treatment planning," study coleader Ashesh B. Jani, MD, a radiation oncologist and prostate cancer specialist at Winship Cancer Institute of Emory University, stated in a press release.
"This research has found that integrating advanced PET imaging using fluciclovine allows us to do a better job of selecting patients for radiation therapy, guiding radiation decisions and planning, and ultimately, keeping our patients’ cancer under control," added Jani.
Overall, the open-label study (NCT 01666808), included 165 patients with adenocarcinoma of the prostate who had cancer recurrence following prostatectomy. Patients had a detectable PSA, a negative bone scan, and CT or MRI of their abdomen/pelvis showing no evidence of extra-pelvic metastases.
Patients were randomized in a 1:1 ratio to either radiation therapy based on conventional imaging (82 patients), or treatment guided by the fluciclovine PET radiotracer following initial CI (83 patients). Patients were randomized from September 18, 2012 to March 4, 2019. The median overall follow-up was 3.52 years.
At the time of the data analysis, the median overall survival had not yet been reached in either study arm.
"The question that we wanted to answer in this study was whether the treatment plan informed by fluciclovine PET imaging had a positive effect in the lives of patients," study coleader David M. Schuster, MD, a nuclear radiology specialist at Winship, stated in the press release. "The significant results of the EMPIRE-1 trial confirm that it does."
The investigators observed similar safety profiles in both study arms. The most common adverse events across the study population were late urinary frequency/urgency and acute diarrhea.
Jani and Schuster are now leading the NIH-funded EMPIRE-2 trial (NCT03762759), which is comparing 18F-fluciclovine-PET/CT with Ga 68 PSMA PET/CT to guide treatment and improve outcomes of postprostatectomy radiotherapy. The open-label trial has a targeted enrollment of 140 patients and the primary outcome measure is disease-free survival. The estimated primary completion date of the trial is December 31, 2025.
1. Winship study published in The Lancet shows increased failure-free survival in prostate cancer. Published online May 10, 2021. Accessed May 18, 2021. https://bit.ly/3bAxTD3.
2. Jani AB, Schreibmann E, Goyal S, Halkar R, et al. 18F-fluciclovine-PET/CT imaging versus conventional imaging alone to guide postprostatectomy salvage radiotherapy for prostate cancer (EMPIRE-1): a single centre, open-label, phase 2/3 randomised controlled trial [published online ahead of print May 7, 2021]. Lancet. 2021. doi: 10.1016/S0140-6736(21)00581-X