Prophylactic Radiotherapy to Prevent Bone Complications in Patients With Metastatic Solid Cancers

Inclusion Criteria: * Age ≥18 years * Histologically confirmed solid malignancy * Metastatic disease confirmed by imaging (CT, MRI, or PET-CT) * Presence of up to five high-risk bone metastases * High-risk bone metastases defined according to protocol criteria * Asymptomatic or minimally symptomatic bone metastases (not requiring opioid analgesics) * ECOG performance status 0-2 * Ability to provide written informed consent Exclusion Criteria: * Prior radiotherapy to the index bone metastases preventing safe treatment planning * Symptomatic bone metastases requiring immediate palliative radiotherapy * Evidence of spinal cord compression * Bone metastases causing significant pain requiring opioid analgesics * Oligometastatic disease suitable for radical treatment * Leptomeningeal disease * ECOG performance status ≥3 * Life expectancy less than 3 months * Any condition that, in the investigator's opinion, would interfere with study participation or assessment