Real-world evidence of 18F-fluciclovine Positron emission tomography/computed tomography performance for recurrent prostate cancer in the Veterans Affairs Health System.

ABSTRACT

BACKGROUND: There are no population-level studies assessing 18F-fluciclovine (fluciclovine) utilization of Positron emission tomography/computed tomography (PET/CT) for biochemically recurrent prostate cancer (PC). We assessed fluciclovine PET/CT in the Veterans Affairs Health Care System. METHODS: Of 1153 men with claims suggesting receipt of fluciclovine PET/CT, we randomly reviewed charts of 300 who indeed underwent fluciclovine PET/CT. The primary outcome was fluciclovine PET/CT result (positive or negative). Comparison among groups stratified by androgen deprivation therapy (ADT) (yes vs. no) and prostate-specific antigen (PSA) (≤1 vs. >1 ng/mL) at imaging were performed. Logistic regression tested associations between PSA, ADT receipt, and race with fluciclovine PET/CT positive imaging. RESULTS: Fluciclovine PET/CT positivity rate was 33% for patients with PSA 0-0.5 ng/mL, 21% for >0.5-1.0, 54% for >1.0-2.0, and 66% for >2.0 (p < 0.01). A 59% positivity rate ocurred in patients treated with concurrent ADT versus 37% in those not on ADT (p < 0.01). White were more likely to have a positive scan versus Black patients (55% vs. 38%; p = 0.02). Patients whose primary treatment was radical prostatectomy had a lower positivity rate (33%) versus those treated with radiotherapy (55%) (p < 0.001). On multivariable logistic regression, PSA > 1 ng/mL (all men odds ratio [OR] 4.06, 95% confidence interval [CI] 2.07-7.96; men on ADT only OR 4.42, 95% CI 1.73-11.26) and use of ADT (OR 3.94, 95% CI 1.32-11.75), and White (all men OR 2.22, 95% CI 1.20-4.17) predicted positive fluciclovine PET/CT. CONCLUSION: This real-world study assessing 18F-fluciclovine PET/CT performance in an equal access health care system confirms higher detection rates than traditional imaging methods, but positivity is highly influenced by PSA at time of imaging. Additionally, patients currently receiving ADT have at least four times higher likelihood of a positive scan, showing that scan positivity isn't negatively affected by ADT status in this study. Finally, White men were more likely to have a positive scan, the reasons for which should be explored in future studies.