Since a systemic therapy alone is incapable of permanently ablating metastatic prostate cancer (mPCa) lesions, we have designed this clinical trial to explore whether its combination with radiation ablation of low volume (≤3 detectable lesions) mPCa, using the novel and highly effective single dose radiotherapy (SDRT), will render cure of a subset of currently incurable mPCa, as achievable in other tumors at the so-called oligometastatic (OM) phase of tumor progression. Whether OM-PCa does, in fact, exist and whether it can be cured has never been systematically researched. The recent introduction of advanced diagnostic and therapeutic platforms provide new tools to address the OM paradigm in mPCa. For example, while the identification mPCa lesions is still challenging, 18F-Choline and 68Ga-Prostate Specific Membrane Antigen (PSMA) Positron Emission Tomography with Computed Tomography (PET/CT) are emerging as effective modalities for the identification of low volume metastases with a pooled sensitivity and specificity exceeding 85%. Hence, the focus of this project is to use modern diagnostic and therapeutic approaches to detect and ablate low tumor-load mPCa lesions, hypothesizing that a subset these tumors will be detected and treated at the OM phase, and may be cured. We propose that systematic studies of each tumor phenotype and their correlation with clinical outcomes will yield not only a validation of the existence of OM-PCa, but will also enable the generation of an algorithm that predicts the OM phenotype upfront and optimizes the treatment strategy.
