HIghly MetAstatic Life Prolonging Therapy-Resistant Prostate Cancer: Role of Stereotactic Radiotherapy for Bone and Lymph Node Metastases (HIMARS)

"The acceptable regimens are:~* 27 Gy / 3 fractions / 3 fractions per week~* 35 Gy / 5 fractions / 3 fractions per week An interval of at least 24 hours should be kept between two consecutive fractions.~Prescription must be defined on 80% isodose or higher, maximum dose up to 130% of the isodose prescription. At least 90% of the Planning Target Volume should receive the prescribed dose. A coverage of \<90% of the Planning Target Volume will be considered as acceptable deviation, and coverage of \<80% of the target volume as an Unacceptable Deviation. At least 90% of the Gross Tumoral Volume should receive the prescribed dose.~Only a part of the Gross Tumoral Volume\_Total could be considered for radiation, depending on the ratio with Bone Marrow Reserve. High-risk and/or symptomatic metastases will be prioritized over other metastases.~Anatomic bone marrow reserve (BMR) will be first determined for each patient:~BMR = Total trabecular bone - (Total trabecular bone ∩ GTV\_Total)"