Value of pre-treatment PET/CT metabolic parameters in prostate cancer patients receiving Lu-177 PSMA treatment

This study aimed to investigate the relationship between the data obtained from Positron Emission Tomography/Computed Tomography imaging performed before Prostate Specific Membrane Antigen-based radioligand treatment in patients with metastatic castration-resistant prostate cancer and the patients' clinic, treatment response and prognosis. Ethics committee approval was received for our retrospective study, and 42 male patients who received Lutetium-177 Prostate Specific Membrane Antigen treatment in our Department between 01.01.2017 and 31.12.2022 and met the inclusion criteria were included in the study. Considering the first treatment date and the last follow-up date, the median follow-up period was calculated as 7.26 (2.96-13.26) months and the median survival was 8.10 (95% CI: 3.63-12.56) months. No statistically significant relationship was found between the parameters obtained from Gallium-68 Prostate Specific Membrane Antigen imaging and treatment response, which is thought to be due to the small number of cases in our study. When 19 patients with dual imaging were divided into 2 groups: discordant and concordant, although no statistically significant survival difference was detected between the groups, a significant difference in the survival curve was observed in favor of the concordant group. As a result, metabolic imaging before Lutetium-177 Prostate Specific Membrane Antigen treatment in prostate cancer; It provides valuable information in assessing the extent of the disease, suitability of treatment and predicting patient outcomes. Radioligand therapy benefits overall survival in metastatic castration-resistant prostate cancer. Prospective studies in which radioligand therapy is administered at earlier stages are needed to evaluate potential higher survival benefits.