Immune Response Evaluation in Oligorecurrent and Oligoprogressive Prostate Cancer Patients Treated With SBRT

"RT treatment Schedule as for clinical practice: Stereotactic body radiation treatment (SBRT) will be delivered with image guidance (image-guided radiation therapy or IGRT) and in the form of volumetric modulated arc therapy (VMAT).~RT treatment Schedule: SBRT will be delivered in 1 to 6 fractions on bone or lymph node metastases. The dose and fractionation schedule will depend on the size and location of the lesion and the surrounding normal tissue constraints."

"ADT as for clinical practice:~* for oligorecurrent patients, ADT will be started at time of polimetastatic progression after SBRT;~* for oligoprogressive patients, ADT will be continued during SBRT and untill polimetastatic progression"

We will use the flow cytometer FACSymphony, to analyse multiple immune populations from a limited sample of blood. We will monitor the dynamics of most innate (monocytic and granulocytic cells, Natural killer cells) and adaptive (T cells, B cells) immune subsets in the peripheral blood of PC patients before and after RT. We will deeply characterize CD4+ and CD8+ T cell subpopulations circulating in the patients enrolled in the study. In this attempt our panel will include markers of T cell differentiation and activation, including CD25, CD39, PD-1, CTL4, KLRG1, TIM3. We will analyse neutrophils subpopulations and investigate the functional profile of granulocytes in enrolled patients. Markers such as CD66b, CD24, CD16, MHC-II, LOX1, CD36 and CD62L will be included in our analysis. In conclusion our experimental strategy will result in a comprehensive profiling of the immune landscape in PC patients at single cell level.