Lu-PSMA and Stereotactic Radiotherapy Versus Radiotherapy Alone for Prostate Cancer (LUST)

Biochemical recurrence (BCR), i.e. prostate-specific antigen (PSA) only recurrence occurs in nearly one-third of patients, after primary definitive therapy for prostate cancer. PSMA (prostate-specific membrane antigen) is an attractive target for diagnosis and therapy of metastasized prostate cancer (PCa) as its expression levels are directly correlated with androgen independence, metastases and progression. Positron Emission Tomography/Computed Tomography (PET-CT) using PSMA is able to detect \> 50% of relapses with PSA between 0.50 and 1 ng/mL and \>75% with PSA between 1 and 2. Oligometastatic prostate cancer include 1-3 asymptomatic metastatic lesion(s) of the soft tissue or bone. The treatment of oligometastatic disease depends on multiple factors including the site, the size, number and location of metastases, and the effectiveness of treatments. Recent advances in radiation therapy allow to image and treat precisely target lesions within any anatomic region of the body. Stereotactic radiation therapy permit highly conformal and precisely targeted radiation administered in a dose intensive strategy. Local control in excess of 75% has been reported for metastatic prostate cancer with very low toxicity. Lutetium 177-PSMA (177Lu-PSMA) is the most extensively investigated PSMA radioligand for radionuclide therapy in castration resistant prostate cancer (CRPC). Several retrospective studies and three phase II prospective studies demonstrated safety and impressive efficacy of 177Lu-PSMA in metastatic CRPC (mCRPC).The purpose of this study is to evaluate in a randomized phase II study the impact of Lu-PSMA added to stereotactic radiotherapy vs radiotherapy alone in PSMA detected- metastatic lesions of hormone-sensible prostate cancer.