Clinical impact of 18F-DCFBC PET/CT in biochemical recurrence prostate cancer patients after treatment with curative intent.

Objectives: To assess the clinical impact of 18F-DCFBC PET/CT, a PSMA targeted PET agent, for lesion detection and clinical management of biochemical relapse prostate cancer patients.

Methods: This is a prospective IRB-approved study including 68 patients with documented biochemical recurrence (average PSA of 4.4 ng/ml) after local therapy either radical prostatectomy (n=50), post radiation therapy (n= 9) or both (n=9), with negative standard conventional anatomical imaging. All patients underwent whole body 18F-DCFBC PET/CT at 1 h and 2 h p.i. and mMRI imaging (62/68 pts), 2 weeks apart. Lesion detection rate of 18F-DCFBC was assessed and correlated with mMRI findings and with pre-scan PSA levels. The impact of 18F-DCFBC PET/CT on clinical management and treatment decision was established after 6 months’ patient follow up.

Results: 41 patients (60.3%) showed at least one positive 18F-DCFBC lesion, identifying a total of 79 lesions, 30 in the prostate bed, 40 lymph nodes, and 9 distant sites. Tumor recurrence was confirmed by either biopsy (13/41 pts), serial CT/MRI (7/41) or clinical follow up (14/41); 3 patients had negative biopsy and 4 are being followed up. The 18F-DCFBC and mMRI findings were concordant for 39 lesions (49.4%), and discordant for 40 lesions (50.6%), 34 of them located outside the mMR field of view. 18F-DCFBC lesion detection rate were 15%, 46%, 83%, 60%, 80% and 100% for PSA values <0.5, 0.5 to <1.0, 1.0 to <2.0, 2.0 to <5.0, 5.0 to <10.0, and 蠅10.0 ng/mL, respectively. A change in management was noted in 75% (30/41) of the patients with positive 18F-DFBCC results, starting new treatment in 25 patients and changing treatment plan of 5 patients.

Conclusion: 18F-DCFBC is helpful in identifying lesion detection in 60.3% of patients with biochemical recurrence prostate cancer, in a population with mixed PSA levels. Furthermore, 18F-DCFBC PET imaging let to a change on clinical management in 75% of patients with a positive scan. Research Support: