The impact of PSMA-PET/CT on clinical decision-making in primary staging of prostate cancer

Abstract Background Accurate staging is essential for optimal management of prostate cancer. Conventional imaging with computed tomography and bone scintigraphy has limited sensitivity and specificity, particularly for small-volume disease. Prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA-PET/CT) has emerged as a more sensitive modality, but its impact on clinical decision-making in primary staging remains to be fully defined. In this retrospective single-center study, we evaluated the impact of PSMA-PET/CT on treatment strategies compared with conventional imaging in patients with intermediate- and high-risk prostate cancer at Skåne University Hospital, Sweden, between October 2020 and December 2022. All patients underwent [ 18 F]PSMA-1007 PET/CT, computed tomography and bone scintigraphy within 90 days. Management decisions were assessed by comparing treatment decisions based on conventional imaging alone with those incorporating PSMA-PET/CT findings, and were classified as major (shift between curative and non-curative treatment intent), medium (modification of surgical or radiotherapy plans without altering overall treatment intent), and minor (additional investigations or minor adjustments resulting in treatment delay without change of intent or modality). Results A total of 287 consecutive patients were included, of whom 59 (21%) had intermediate-risk and 228 (79%) high-risk disease. Overall, 187 patients (65%) had negative findings on all imaging modalities, while 100 (35%) had positive findings. PSMA-PET/CT identified lesions in 94 patients, whereas only 6 patients had positive findings exclusively on conventional imaging. PSMA-PET/CT led to a change in clinical management in 65 patients (22.6%), including major changes in 31 (10.8%), medium changes in 28 (9.9%), and minor changes in 6 (2.1%). Among patients with positive PSMA-PET/CT findings ( n = 94), 32.0% experienced major, 29.8% medium and 5.2% minor treatment modifications. Management changes were more frequent in high-risk patients (24.6%) compared to intermediate-risk patients (15.3%). Conclusion PSMA-PET/CT provides actionable information that leads to changes in clinical management in approximately one in four patients undergoing primary staging of prostate cancer, with the greatest impact observed in high-risk disease. These findings support the integration of PSMA-PET/CT into routine staging to enable more precise and individualized treatment planning.