F-DCFPyL PET/CT for primary staging in 160 high-risk prostate cancer patients; metastasis detection rate, influence on clinical management and preliminary results of treatment efficacy.

PURPOSE

Prostate-specific membrane antigen (PSMA) PET/CT shows better diagnostic performance for detection of lymph node and bone metastases as compared to conventional imaging. Studies of PSMA PET/CT in primary staging comprise highly selected patient cohorts. This study evaluates F-DCFPyL PET/CT as first-line imaging modality for primary staging of high-risk prostate cancer.

MATERIAL

From February 2018 until April 2019, all patients with high-risk prostate cancer received F-DCFPyL PET/CT for staging of prostate cancer. Baseline characteristics, findings at F-DCFPyL PET/CT, number and type of required additional diagnostic procedures, findings at additional diagnostic procedures, and effects of therapy on PSA levels for all patients treated with curative intent were collected and evaluated.

RESULTS

One hundred-sixty patients were included in the study of which 90 (56%) had evidence of metastasized disease (N1, M1a, M1b and, M1c in 49%, 28%, 31%, and 3% respectively). Additional diagnostic imaging was needed in 2/160 patients (1%) because of equivocal findings on F-DCFPyL PET/CT. Eighty-one patients had evidence of PSMA-positive lymph node metastases, of whom 39 (48%) had no enlarged lymph nodes on CT; F-DCFPyL PET detected additional metastatic lymph nodes in 41/42 patients that had evidence of lymph node metastases on CT. F-DCFPyL PET altered patients' management in 17% of patients.

CONCLUSION

F-DCFPyL PET/CT can be used as first-line imaging modality for therapy selection in patients with primary high-risk prostate cancer, without need for further diagnostic imaging procedures in the majority of patients.