Clinical outcome of PSMA-guided radiotherapy for patients with oligorecurrent prostate cancer

Ziel/Aim First line treatment of patients with recurrent, metastatic prostate cancer is a combination of hormone therapy with or without chemotherapy/abiraterone, as a systemic, palliative treatment. A new perspective is given by PSMA-PET/CT-guided irradiation, which demonstrated promising efficacy in recent trials. The current study aimed to classify the type and localization of metastases after primary treatment and its clinical outcome.

Methodik/Methods Between 2011 and 2019, 86 patients (mean age of 69 years) with recurrent, oligometastatic prostate cancer received a PSMA-PET/CT followed by a precise irradiation of their metastases. 60 patients underwent a clinical follow-up including a quality of life status. Data were analyzed retrospectively regarding the region of relapse and the primary endpoints overall survival (OS), biochemical progression free survival (bPFS) and androgen deprivation therapy (ADT)-free survival.

Ergebnisse/Results The median follow- up was 24 months (range 4–72). According to the d’Amico risk classification, 90.7 % of all patients were categorized as high-risk. A median amount of 1.0 metastasis per patient could be identified. In total, 49.4 % of the metastasis were considered as metastasis of the bone, 34.1 % were nodal metastases within and 16.5 % nodal metastases outside of the pelvis. A 2-year OS rate of 95.7 % and a 2-year bPFS rate of 85.1 % were calculated. The data analysis revealed a mean ADT- free time of 15.9 months (range 3–40). Biochemical response was detected in 83.3 % of the cohort. If a progress monitoring via PSMA-PET/CT was implemented, the standard uptake value (SUV) of the irradiated metastases was reduced significantly.

Schlussfolgerungen/Conclusions PSMA-guided radiotherapy is a promising, novel therapeutic approach for oligorecurrent prostate carcinoma to extent OS and bPFS in comparison to systemic therapy and should be more considered in the recurrent situation. However, prospective, randomized trials are necessary to confirm and validate the analyzed data with a larger cohort of patients.