Stereotactic Body Radiotherapy With or Without Darolutamide for OligoRecurrent Prostate Cancer

As of the 2018 EAU guidelines, PSMA PET-CT is now recommended for prostate cancer patients with a rising PSA following local therapy, resulting in an increase in patients with conventional imaging M0, but novel imaging M1-state. This creates a new class of patients for which no clear guidelines exist on the optimal management. It became clear that there is no real consensus nor data on how these patients should be treated. In 1995, a new approach was proposed, hypothesizing that patients with a limited number of metastases (oligometastases) might benefit from eradication of metastases by means of local therapy, or metastasis-directed therapy. Stereotactic body radiotherapy (SBRT), a novel radiotherapy technique for metastatic and primary prostate cancer treatments, has emerged as a highly precise radiotherapy method able to eradicate small metastases with acceptable toxicity. Nevertheless, responses following SBRT were not always durable. To improve response rates and time to new metastases, additional steps should be taken balancing with potential added toxicity. One of the logical steps would be to combine SBRT with temporary androgen deprivation therapy (ADT) as this combination therapy is standard of care for primary PCa and locally recurrent PCa17. However, ADT, negatively impacts quality of life (QoL) even when used temporary. Anti-androgen or androgen receptor (AR) pathway inhibitors (ARpI) may circumvent these side effects by suppressing AR transcription by competitive inhibition of AR, without lowering systemic testosterone. The current trial will test the combination of darolutamide with SBRT, in oligometastatic recurrent hormone sensitive prostate cancer. We hypothesize that the addition of short-term darolutamide improves metastasis-free survival when added to SBRT without a detrimental impact on the QoL.