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 important 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. The aim of this study was evaluate 68 Ga PSMA PET-CT imaging in initial staging-first line imaging of prostate cancer from low to high risk patients.

Materials & Metods: 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. There were a total of 27 low risk, 35 intermediate risk and 114 high risk patients included in the study. SUVmax in the primary tumor was correlated significantly with PSA levels and patient risk group. Mean SUVmax value 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), whereas multipl metastases were detected significantly higher in high risk group patients (3.7 %, 8.6 % and 52.6 %, in low, intermediate and high risk patients respectively.

Conclusions: Oligometastases was detected with a relative 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 found to be quite useful in the current study. Ga-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 large number of patients.