Comparison of tumoral foci in prostate needle biopsy of patients with prostate cancer and prostate involvement in GA-68 PSMA PT CT

Prostate cancer is the most common urogenital system malignancy in the male population and is the second most common cause of death after lung cancer among malignancies. PSMA PET/CT is used in the staging of prostate cancer, determining the treatment modality, evaluating the prognosis, locating the lesion in the presence of suspected recurrence or biochemical recurrence, and evaluation of the post-treatment response. The aim of this study is to compare the prostate involvement and degree detected on imaging and histopathological findings in patients who were diagnosed with prostate adenocarcinoma histopathologically as a result of prostate needle biopsy and then underwent PSMA PET/CT, and to examine the correlation of involvement with clinical and prognostic factors. Patients who were diagnosed with prostate adenocarcinoma histopathologically with TRUS-Bx in our hospital and then Ga-68 PSMA PET/CT were scanned retrospectively from the hospital data system, and a total of 84 patients were included in the study. The prostate was divided into 6 quadrants and a total of 504 quadrants were examined. PSMA PET/CT images were re-examined unaware of the pathology results, and SUVmax values were recalculated for each quadrant. Patients' age, PSA value, gleason score in biopsy pathology result, tumor percentage, SUVmax values in prostate gland in Ga-68 PSMA PET/CT images were evaluated. The mean age of the 84 patients included in the study was 68.4 (range 46-82) and the median PSA value was 12.7 ng/ml. With the data obtained from this study, the SUVmax cut-off value was found to be 1, and Ga-68 PSMA PET/CT was found to have 99.4% sensitivity and 92.1% specificity for prostate cancer. When the Gleason grade groups were compared in terms of SUVmax values in the tumor-detected quadrants, a statistically significant difference was found between them (p<0.001). There was a positive correlation between SUVmax values in tumor-detected quadrants and Gleason grade groups, PSA values and tumor percentages (r=0.349 p<0.001, r=0.349 p<0.001, r=0.379 p<0.001, respectively). Ga-68 PSMA PET-CT accurately demonstrates tumor localization within the prostate, so that the target lesion can be accurately located prior to prostate biopsy. SUVmax values detected in Ga-68 PSMA PET/CT are related to the Gleason grade group and PSA values of the patients, and SUVmax values can be used as prognostic factors like these determinants. As a result, it was concluded that Ga-68 PSMA PET/CT can contribute significantly to diagnosis, treatment and follow-up in prostate cancer. Key words: Prostate cancer, Prostate biopsy, Ga-68 PSMA PET/CT