Ga-68 PSMA PET-CT in Initial Staging First Line Imaging of Prostate Cancer: The Clinical Impact of Oligometastatic Disease

Abstract

Background: Imaging plays an essential role in the evaluation of prostate cancer patients. In recent years, much attention has been focused on 68Ga-PSMA PET-CT in prostate cancer patients and has been widely used for staging, especially biochemical relapse-restaging and therapy response for these patients. This study aimed to evaluate 68 Ga PSMA PET-CT imaging in initial staging-first line imaging of prostate cancer from low to high risk patients. Materials & Methods: Patients with low, intermediate and high risk newly diagnosed prostate cancer referred for initial staging of prostate cancer were included in the study. Histopathology and follow-up clinical and radiological information after PET/CT scanning served as the standard of reference. Results: The study included a total of 176 consecutive patients underwent 68 Ga PSMA PET-CT for initial staging with prostate cancer final histopathology result. The study included a total of 27 low-risk, 35 intermediate risk, and 114 high-risk patients SUVmax in the primary tumor was correlated significantly with PSA levels and patient risk group. Mean SUVmax values of the primary prostate lesion were 16.6 %, 25.8 % and 35.2 % in low, intermediate and high risk patients, respectively. Oligometastases were detected in low and intermediate groups in similar proportions and slightly less in high risk patients (22 %, 22.8 % and 15.7 % in low, intermediate and high risk patients respectively), In contrast, in low, intermediate, and high-risk patients, multiple metastases were detected significantly higher in high-risk group patients (3.7 %, 8.6 %, and 52.6 %, respectively). Conclusions: Oligometastases were detected with a relatively high rate in low- and intermediate-risk group patients. Ga-68 PSMA PET-CT imaging in newly diagnosed prostate cancer patients, even in low-risk patients, was quite valuable in the current studyGa-68 PSMA imaging should be done in all risk groups as a first-line imaging modality. This finding should be supported by other studies with the large number of patients.